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Biochemical and Pharmacological investigations of selected cyanobacteria
Abstract
Cyanobacteria are a very old group of prokaryotic organisms that produce a variety of secondary metabolites with antibiotic, algicide, cytotoxic, immunosuppressive and enzyme inhibiting activities. In the last decades structures of pure compounds have been determined as phenols, peptides, alkaloids or terpenoids (Falch, 1996). Screening of lipophilic and hydrophilic extracts from cultured cyanobacteria or waterbloom material, isolated from German lakes and the Baltic sea for antiviral, antibiotic, immunomodulating and enzyme inhibiting activity in different in vitro systems revealed strains with interesting effects. These strains were cultivated in 45 litre photobioreactors to produce enough biomass for bioassay-guided isolation of the active substances. First results characterising active substances are reported.
... Disc diffusion method for antimicrobial susceptibility test was carried out according to the standard method given by Mundt et al. (2001) to assess the presence of antibacterial and antifungal properties of the extract. Bacterial and fungal cultures (which have been adjusted to 0.5 McFarland standard), were used for lawn Muller Hinton and PDA agar plates respectively. ...
... High metabolite yield was obtained in the methanol extract (60%) compared with hexane (10%) extract, this may be due to the presence of moderately polar compounds in methanol extract. A similar result was recorded by Mundt et al., 2001 for Chlorococcus species in methanol extract. It was foundthat high percentage of methanol extracts with positive effects against S. aureus indicated a higher chance of finding antimicrobial chemicals in methanol extracts. ...
... In the present study, similar impressed results of antibacterial and antifungal properties were found in methanol extract compared to hexane extract. Cyanobacteria belong to the Gram-negative bacteria; therefore, their metabolites have stronger activity against Gram-positive bacteria and yeasts (Mundt et al., 2001). This fact supports the assumption that these metabolites can be produced to protect cyanobacteria themselves from competing for organisms (Piccardi et al., 2000;Mundt et al., 2001;Bhadury and wright, 2004;Martins et al., 2008). ...
Cyanobacteria, highly diverse group of prokaryotes are recognized as a potent source of biologically active compounds with antiviral, antibacterial, antifungal, and anticancer properties.The aim of the present study was to screen antibacterial, antifungal and cytotoxic activities of intracellular secondary metabolites of freshwater cyanobacterium Oscillataria sp. Cyanobacterium Oscillatoria sp. was isolated from Senanayaka Samudraya reservoir (7 0 11' 37.37 0 N 81 0 31' 47.13 0 E), Sri Lanka.In vitro antibacterial and antifungal activity of Oscillatoria sp. was screened against Gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 25923, Bacillus anthracis and Gram-negative Pseudomonas aeruginosa (ATCC 25853), Salmonella typhi and Escherichia coli (ATCC 25922) and fungi, unicellular Candida albicans (ATCC 60192) and Candida tropicalis using agar disc diffusion method.The Minimum Inhibitory Concentrations (MIC), Minimum Bacteriocidal Concentration (MBC), Minimum Fungicidal Concentrations (MFC) and cytotoxic effects (brine shrimp bioassay) of Oscillatoria crude extract were determined. 10% and 60% of biomass was extracted with hexane and methanol respectively.Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify compounds in the crude extract. The highest antibacterial and antifungal activity of crude extract were detectedin methanol extract against S.aureus (19±2 mm)and C.albicans (10±1 mm) within 24 hours wherein the hexane extract, antibacterial activity was detected only for S. aureus and mean diameter of inhibition zone was 11±1mm within 24 hours.The lowest MIC of methanol extract against S. aureus wasfound as 156.25 µg/ml. The lowest MBC and MFC of methanol extract againstS. aureus and C.albicans were 0.63 mg/ml and 1.25mg/ml respectively. Lethal concentration, 50% of the crude extract against brine shrimp was recorded at 2.50 g/l, 1.25 g/l and 0.625 g/l for 6, 12, 24 hrs intervals respectively. GC-MS analysis revealed that the methanol crude extract of Oscillatoria sp. contains important fatty acid namely hexadecanoic acid methyl ester, methyl tetradecane and 13-tetradecanoic acid and n-hexane extract contains Bis (2-ethylhexyl hydroxypyridine oxide, 1 2-benzenedicarboxylic acid mono (2-ethylhexyl) ester, Phthalic acid 6-ethyl-3-Octyl heptyl ester and Phthalic acid dodecyl nonyl ester which may possess antibacterial and antifungal properties.
... Different solvents are stated as being the most effective solvent to use for extracting antimicrobial compounds in the disc diffusion assay (Table 1) ranging from non-polar compounds such as hexane (Kellam and Walker, 1989;Mundt et al., 2001;Sushanth and Rajashekhar, 2015), diethyl ether (Mc Gee et al., 2020), chloroform (Abo-State et al., 2015) and ethyl acetate (Biondi et al., 2008) to polar compounds such as methanol (Bhateja et al., 2006;Cannell et al., 1988;Pawar and Puranik, 2008;Soltani et al., 2005). A greater number of MIC values are reported in the literature for extracts made using polar solvents e.g. ...
... Some compounds are also active against drug-resistant antibacterial strains and so could potentially provide promising leads in pharmaceutical drug development (Table 7). For example, Hapalindole T isolated from Fischerella sp. was extremely active (MIC 0.25-32 μg/mL) against a MDR E. coli strain and M. tuberculosis (Asthana et al., 2006) and the fatty acid α-linolenic acid isolated from Limnothrix redeki (Order Oscillatoriales) was active against a MDR Staphylococcus strain (Mundt et al., 2001). ...
While there are many opportunities to use microalgae as antimicrobial agents, little has been done to develop them beyond the characterization phase to the biotechnology phase. One challenge when screening microalgae for antimicrobial activity is their ability to synthesize biologically active secondary metabolites in response to environmental triggers. In order to identify potential strains with good antimicrobial activity and to advance the development of microalgae as antimicrobial agents, a rigorous scientific approach is required. Microalgae are most commonly screened for antimicrobial activity using the disc diffusion assay but this assay is problematic and produces false-positive and false-negative results. Quantitative minimum inhibitory concentration (MIC) values generated in assays such as the microdilution broth assay are more reproducible and enable comparison of results between research groups. For the present review, a dataset was compiled of published MIC values for microalgae. The Cyanobacteria and Chlorophyta were the best represented and other phyla were under represented. This data was used for assessment of factors influencing antimicrobial activity, including test microorganisms, microalgae taxonomy, different solvents for extraction and the growth phase at harvest. Activity was considered good if MIC values were < 1 mg/mL, moderate if MIC values were 1–8 mg/mL and weak with MIC >8.0 mg/mL. Areas requiring more research are discussed including screening a greater diversity of species in appropriate assays, reporting negative results, testing the culture supernatant for activity, synergistic effects and identifying antimicrobial compounds in the Chlorophyta. The potential for successful development and commercialization of microalgae antimicrobial agents will increase as more microalgae are screened and compounds identified.
... Screening of cyanobacteria for antibiotics and pharmaceutically active compounds has received great attention since there is an increasing trend in the identification of biological resources for the production of bioactive compounds. This has prompted the scientific community to screen cyanobacteria for antibacterial, antifungal, antiviral, anticancer and antiplasmodial activities (Patterson et al., 1992;Gerwick et al., 1994;Papendorf et al., 1998;Jaki et al., 2000;Mundt et al., 2001). The ability to produce antimicrobial substances may be attributed to the defensive nature to survive in different habitats of the species and also a good source of new bioactive compounds. ...
... The methanol extract showed good activity against bacteria as compared to other extracts which also agreed with our results, where methanol extract showed maximum inhibition activity, whereas acetone extract of Spirulina subsala and Phormidium corium and ethanol extracts of Oscillatoria pseudogeminata showed high inhibition activity against P. aeruginosa and S. aureus (Reehana et al., 2012). Mundt et al. (2001) observed that the extract of Anabaena variabilis inhibited the growth of only B. subtilis. Antimicrobial activity of cyanobacteria isolated from a freshwater lake was studied by Madhumathi et al. (2011) where Oscillatoria latevirens, Chrococcus minor, Microcystitis aeroginosa were found to have antifungal activities against Candida albicans which also agrees with our findings that cyanobacterial species exhibited antifungal activity against C. albicans. ...
... Cyanobacteria are accredited synthesis of biologically active and structurally dierse secondary metabolites (Le Flaive and Ten-Hage, 2007). Thses compounds exhibit potent activity against organism including viruses, bacteria, fungai and other algal species (Carmichael, 1992;Patterson et al., 1993;Skulberg, 2000;Mundt et al., 2001). Selected inhibitory agents may serve as prospective candidates for development of natural biopharmaceuticals (Gerwick et al., 1994;Sandsdalen et al., 2003). ...
... Similarly toxin from Acutiphycin (Phospholipid compound) from Oscillatoria acutissima showed promising antitumor activity. Likewise Mundt et al. (2001) described the anticancer effect of toxin (Linolenic acid) from Oscillatoria redekei, Fischerella sp, against cancers of the breast and colon. Based on the cytotoxicity screening results, the present investigation revealed that the GC fractionated Benzeneacetanomide and Norvaline, n-propargyloxycarbonyl (Pyrrol deriatives) is non-toxic in nature. ...
The biomedical applications of the secondary metabolites produced by the harmful algal blooms were studied over a few decades ago. Only few research studies have been reported on the medicinal properties of the secondary metabolites produced by the cyanobacteria Microcystis aeruginosa. The present study was aimed to screen the Biological activities of GC fractionated Benzeneacetanomide and Norvaline, n-propargyloxycarbonyl mixtures of Microcystis aeruginosa secondary metabolites. The Microcystis aeruginosa samples were collected by plankton net from the blooming area at Muttukadu. The metabolites were extracted by using polar solvent as methanol. The yield percentage of Microcystis aeruginosa methanolic extract showed moderate level of 41% from the dry weight of the pre extracted Microcystis aeruginosa powder. The crude metabolites were purified through column chromatography and GC-MS analysis. The GC-MS results showed the presence of two compounds (2 major peaks), Benzeneacetamide at the retention time (RT) of 7.315 min and l-Norvaline, n-propargyloxycarbonyl (Pyrrol derivaties) at the retention time (RT) of 12.541 min. The GC-MS fractioned compounds were characterized by FT-IR and ¹HNMR. The anticancer, antioxidant and antimicrobial activity of the compounds were studied. This study highlights the bioactive potential of Microcystis aeruginosa secondary metabolites that might lead to the development of cancer drug.
... Cyanobacteria strains have been found to produce intracellular and extracellular metabolites with a wide range of biological activities, including antibacterial, antifungal, cytotoxic, algaecide, immunosuppressive, and antiviral activities. (Mundt et al.,2001).Spirulina, a blue-green algae, is rapidly becoming a popular health food worldwide. It is a photoautotrophic Cyanobacterium from the class Cyanophyta that is edible, minute, multicellular, filamentous, and alkalophilic. ...
... Cyanobacteria strains have been found to produce intracellular and extracellular metabolites with a wide range of biological activities, including antibacterial, antifungal, cytotoxic, algaecide, immunosuppressive, and antiviral activities. (Mundt et al.,2001).Spirulina, a blue-green algae, is rapidly becoming a popular health food worldwide. It is a photoautotrophic Cyanobacterium from the class Cyanophyta that is edible, minute, multicellular, filamentous, and alkalophilic. ...
... Cyanobacteria are regarded as good candidates for drug discovery with applications in pharmaceuticals. 33 Cyanobacteria have shown activity toward Bacillus subtilis, Bacillus thuringiensis, Bacillus megaterium, E. coli, P. aeruginosa, Candida tropicalis and Saccharomyces cerevisiae. 34 It was reported that extracts of Oscillatoria, Phormidium and Lyngbya obtained by different solvents exhibited antimicrobial activity on both gram positive and Gram negative organisms. ...
The present study reported the biogenic synthesis of silver nanoparticles using paddy inhabitant cyanobacteria Anabaena iyengarii. The synthesized silver nanoparticles were characterized by UV-vis, FT-IR, SEM and XRD analysis. The UV-Vis spectrum revealed a characteristic surface plasmon resonance peak at 423 nm which corresponds to the absorption band of silver nanoparticles. FTIR spectrum and X-ray diffraction patterns confirmed the formation of silver nanoparticles. The SEM results showed that synthesized silver nanoparticles were spherical shaped with size of 54nm. In this study, the efficiency of silver nanoparticles as an antibacterial against maximum zone of inhibition on Staphylococcus aureus followed by Pseudomonas aeroginosa and E. coli was evaluated. This study elaborated the process of biogenic silver nanoparticles formation via green chemistry approach. Antibacterial activity was also analyzed.
... In a few years, the focus shifted to these organisms because of their ability to produce fertilizer, food, and fuel. Algae as a fertilizer have been studied for various purposes such as manufacturing biopesticide, biofungicide, and nutrient enhancers [1]. The present work focussed on the vast use of algae as a fertilizer with industrial applicability for a various commercial industrial application. ...
In rain-fed crop, after the first monsoon rain, the farmers plow their lands and sow seeds. Because of the lack of moisture in the soil, sown seeds fail to germinate and are eventually destroyed. As a result, the farmers suffer economic losses. To address this issue, seed encapsulation with seaweed powder was performed. Micro (Spirulina plantensis and Chlorella vulgaris) and macroalgae (Sargassum, Halimeda macrolaba, and Gracilaria) were collected from the southeast coast of India. The seaweeds were dried, powdered, and weighed about 1 g of each and were filled in a gelatin capsule. Soil profile (pH, EC, water percolation rate, moisture content, water holding capacity, capillary action, N, P, K, Zn, Fe, Cu, and Mn) was characterized before cropping. Abelmoschus esculentus, Raphanus sativus, Helianthus annuus, and Capsicum annum cultivation were done. The plant growth and yield were analyzed. The texture was clay loamy soil with micro and macronutrients present in it. In Abelmoschus esculentus, the number of leaves, plant height, and branches were increased as compared to control. Sargassum treatment shows highest yield (285.6 g) of A. esculentus. The nutritional quality was enriched in Sargassum treatment followed by C. vulgaris and S. platensis. In Raphanussativus L. cultivation, the estimated yield is as follows: in Sargassum (5.95 kg), C. vulgaris (5.10 kg), S. platensis (3.95 kg), and control (3.15 kg). The yield of Helianthus annuus L. cultivation showed increased in Sargassum treatment of about 200.5-g total seed weight. The yield was higher in Sargassum treatment as compared to C. vulgaris and Gracilaria in Capsicum annum cultivation. Sown seeds in novel seed encapsulation remain undamaged in soil until favorable rainfall occurs. Another benefit is that a marine source biofertilizer enriched with macro/micronutrients and hormones was encapsulated around the seeds, promoting plant growth and yield. The application of fertilizer to a large area is both costly and time consuming. In contrast, applying to specific roots around the plant is both effective and cost effective in terms of plant growth. This novel seed encapsulation with marine source biofertilizer has two advantages: (i) it protects the seed from damage and (ii) it supplements plant nutrition. As a result, farmers lose less and profit more by using less biofertilizer.
Graphical abstract
(a) Powder of micro and macroalgae. (b) Seeds. (c) Encapsulation of seed with micro and macroalgae powder. (d) Encapsulated with macroalgae. (e) Encapsulated with microalgae. (f) Encapsulated with micro and macroalgae. (g) Dissolving of gelatin in soil. (h) Experimental field. (i) Capsule placing inside the soil. (j) Capsule in soil. (k) Seed germination. (l) Plant growth. (m) Ladies finger yield. (n) Sunflower yield. (o) Radish yield
... These metabolitesare used asnatural therapeutics but also as structural models in the production of synthetic molecules. Biologically active substances were extracted from cyanobacteria (Mundt et al., 2001;Volk et al., 2006). Microalgae have meanwhile been found to produce antibiotics: manymicroalgal extracts and/or extracellular products have proven antibacterial, antifungal, antiprotozoal, and antiplasmodial properties. ...
Spirulina plantensis is a filamentous, spiral-shaped alga used as a primary source of food over the years. They are suspected to have antioxidant and antimicrobial activities. Therefore, this study aimed at determining the antimicrobial activities of Spirulina plantensis extracts in Owo local government, Ondo-State, Nigeria. Spirulina platensiswas sampled from the Enete river and cultivated in the laboratory on synthetic media andriverwater. The biomass was harvested after ten days, and extraction of bioactive compounds was carried out using the maceration method. The ethanols, hot and cold-water extracts of S. plantensis were tested against pathogenic strains of Staphylococcus aureus and Pseudomonas aeruginosa using the agar well and disk diffusion methods. The extracted pigments were identified by thin-layer chromatography. The results showed that the tested microbes were resistant to thebioactive compounds in S. plantensis algal extract. Comparative antibiotic tests against the bacteria strains showed resistance to all antibiotic disks used. The growth pattern of the algae on the synthetic medium was poor as compared to that of river water used as control. There was a deterioration of the algae growth from day three of cultivation on the synthetic medium which could be attributed to nutrient depletion. Thin-layer chromatography revealed bands that confirmedthat biological components were present in the algae which were xanthophylls, chlorophyll b, chlorophyll a, Beta-carotene and phycobiliprotein.
... In addition, it has a simple cellular structure; they are morphologically diverse, including unicellular, colonial, filamentous, and branched forms, sometimes forming aggregates visible to the naked eye (Mazard et al. 2016;Borowitzka 2018). In a way, cyanobacteria use water for photosynthesis and produce oxygen, releasing it into the atmosphere (Mundt et al. 2001). ...
... In economic terms, several cyanobacteria are important contributors of carbon and nitrogen bioavailability in the terrestrial ecosystem and are found frequently associated with nondiazotrophic organisms in symbiosis. Members of the terrestrial cyanobacteria also proved an extremely valuable source of novel compounds [10,11], rendering an important selective advantage [12] to this group. Cyanobacteria were not only revealed as a rich source of antimicrobial metabolites [13] but also have cytotoxic efficacy [14][15][16][17], with promising results [18], ability to detect fungal toxins [19], pesticide residues, and monitoring toxicity of organic wastes in marine biomes [20]. ...
From the oasis of Cholistan, true branching heterocystous cyanobacterial strains were studied for, the cell arrangement in primary branches being mono‐ or bi‐seriate; shape of cells in main filament large and irregular; profused secondary branching emerging on one or both sides and tapering along their length. In these observed traits, two clear morphological taxa were recognized, both well assorted from the previously described species of the genus Westiellopsis. Both strains showed culturing response and studied for antibacterial, cytotoxic and anticancer potentials. The strain derived from the site B‐10 provenance exhibited antibacterial activity against Pseudomonas (18 mm); Klebsiella (15 mm), Staphylococcus (22 mm). On the contrary, the strain of site A‐44 showed no activity against any of the above‐mentioned bacterial strains. The cytotoxicity assay for the strain of B‐10 site showed a 36% larval mortality, whereas the strain A‐44 showed 24% larval mortality. Performance of the strain B‐10 in MTT assay (assessed on HCT‐116 cell lines) revealed a dose‐dependent activity: @200 µg/ml, 100 µg/ml, 50 µg/ml and 25 µg/ml; achieving a growth inhibition of 50.15%, 40.22%, 33.72% and 10.21%, respectively; and the strain of A‐44 could only exhibit a 30.06% growth inhibition @200 µg/ml. The 16S rDNA sequencing revealed the sequence homology with Neowestiellopsis. Based on data presented here we report two diverse taxa of true branching Nostocales from Cholistan oasis, Pakistan. This article is protected by copyright. All rights reserved.
... The success of cyanobacteria as ecological group in a wide range of habitats has been attributed to their unique physiological characteristics, which bestows them with a high adaptive ability under a wide range of environmental conditions (Prasanna et al., 2012). They are a ubiquitous group of prokaryotes, whose evolution (amply supported by fossil and molecular evidence) can be traced back 3.5 billion years (Mundt et al., 2001). Although cyanobacteria are globally important primary producers, exhibiting a worldwide distribution in diverse ecosystems and contributing significantly to the fertility of rice fields, research on their role as biofertilizers is gaining interest since the last decade. ...
Biofertilizers containing living organisms are attractive because of their potential positive impact on plant growth and reduced environmental effect compared to mineral fertilizers. Many studies have reported the potential of plant growth-promoting rhizobacteria (PGPR) and cyanobacteria, applied singly or in combination. In the present study, the combined effect of PGPR and cyanobacteria on Triticum aestivum L. was examined in a hydroponic growth system. Calothrix sp. and Anabaena cylindrica were used as cyanobacterial strains, and Chryseobacterium balustinum, Pseudomonas simiae and Pseudomonas fluorescens were used as PGPR strains. In addition to growth parameters, total nutrients in each treatment and the ability to produce indole acetic acid (IAA) were measured after 17 days of treatments. The study results indicate that the consortium of the five isolates gave the best performance in terms of growth parameters. It increased by 36% for plant height in the combination of Calothrix sp. and P. simiae, and the dry shoot mass was increased by 80%, 77%, and 76% under the combinations of A. cylindrica with C. balustinum, P. simiae, and P. fluorescens, respectively. The ability to produce IAA was confirmed in the treatments with cyanobacteria, with PGPR strains, and in treatments combining the different microorganisms, using both colorimetric and chromatographic methods. Thus, biofertilizers containing the consortia cyanobacteria and PGPR used in this study are recommended for improved growth of wheat plants.
... Natural products have been isolated from a wide variety of taxa and tested for various biological activities. Among these taxa, cyanobacteria are regarded as good candidates for drug discovery, with applications in agriculture [3], industry [4] and especially, in pharmaceuticals [5]. Although cyanobacteria are still primarily viewed as an environmental nuisance or a source of toxins, hazardous to man and aquatic livestock, there are many potential benefits to research on chemicals produced by these organisms. ...
... Different bioactive compounds like nostocine A (Hirata et al., 1996) and tenuecyclamide A-D (Banker & Carmeli, 1998) from N. spongiaeformae, noscomin (Jaki et al., 1999) and comnostin A-E (Jaki et al., 2000) from N. commune, borophycin (Hemscheidt et al., 1994), muscoride (Nagatsu et al.,1995), cryptophycin (Biondi et al., 2004) and nostocarboline (Becher et al., 2005) from N. linckia, N. muscorum, N. ellipsosporum, Nostoc ATCC 53789 and Nostoc 18-12A respectively have been reported. Methanol as a control was not able to inhibit microbial activity but methanol extracted nostophycin exhibits antimicrobial activity against bacteria, different workers also adopted methanol extracts for evaluating antibacterial activity (Asthana et al., 2009);Jaki et al.,, 2000;Mundt et al., 2001). The inherent capacity to produce specific bioactive compounds from methanolic extract of Nostoc strain ATCC 53789 seems to play an antifungal role against a variety of pathogens of different agricultural importance fungi such as Armillaria sp., Colletotrichum coffeanum, C. trifolii, Fusarium solanii, F. oxysporum f. sp. ...
Different types of peptides are produced by cyanobacteria of the genus Nostoc, which are unique in structure and have a wide spectrum of biological activities. The objective of the study to explore different habitats of organism and study antimicrobial activities to improve their pharmaceutical application and drug like properties by structure modification. A cyclic peptide nostophycin was isolated from Nostoc calcicola (MK506349) through freeze dried lyophilization method. Its structure has been elucidated with FT-IR, 1HNMR, 13CNMR and LC-MS. Glycine, d-glutamine, l-phenylamine, d-isoleucine, l-proline and a novel amino acid Ahoa are constituents of nostophycin. 1HNMR, 13CNMR spectroscopy confirmed the number of protons and carbons, and characteristics peak determined the structure and fragmentation pattern through LCMS. Nostophycin possess Ahoa instead of Adha which makes it different from microcystin. Nostophycin exhibits antimicrobial activity against E.coli, S. aureus, C. albicens and A. niger. A good antifungal activity (9-52 μg/mL) and moderate antimicrobial activity (concentration 18-52 μg/mL) were found for nostophycin. In case of already known peptides, these molecules may be further exploited to improve pharmaceutical application and future drug development.
... Cyanobacteria are a major source of bioactive metabolites or compounds that contain a varied range of nitrogen-rich alkaloids and peptides (Gervick et al. 2001). The significance of such microbes, which are known as the source of cyano-toxins and different other newly found biologically active compounds, is accepted and recognized worldwide (Mundt et al. 2001;Kumar et al. 2005); however, their role as a chemical potential agent like biocontrol agents or in crop protection is less explored in agriculture. The attack of a disease-causing organism like bacteria, fungi, zooplankton and eukaryotic microalgae could be reduced possibly by using cyanobacteria as a potential defense option of synthesis of highly active toxins. ...
Plant pathogenic biocontrol agents in the very wide-ranging sense encompass
the methods for utilization of organisms except for human. Among all
the microorganisms, cyanobacteria and algae are distinguished bioactive
agents which have gained a remarkable consideration by scientists globally.
Cyanobacteria, autotrophic blue-green algae which are known to be the
most diverse, largest and abundantly distributed group of small, prokaryotic,
unicellular and photosynthetic organism, found specifically in fresh and marine
water, all together with eukaryotic algae ‘could have been the world’s largest
biomass’, whereas algae were found either in marine or in freshwater habitat
with a large number of species found in soil. They are mostly photosynthetic;
however, a great number are heterotrophic facultative species while few are
non-photosynthetic/heterotrophic obligates. Both cyanobacteria and algae
were used hardly as beneficial extracts against pathogenic fungus because of
their stimulation effect for plant productivity and vigour. They have also been
used as media substrates for microbial cultures. Cyanobacteria function as
the most significant source of naturally occurring bioactive compound with
antiprotozoal, antimicrobial, antibacterial, antiviral, anti-proliferative and
anticancer activities. Anabaena, Microcystis, Nostoc and Calothrix have been
observed to counter inhibitory effect against various fungal pathogens, and
also several other species, i.e. Noscomin and Nostocarboline, were found to
exhibit antibacterial activity and inhibit the growth of cyanobacteria. Both
cyanobacteria and algae have shown a significant role against various fungal
and bacterial infections, working as plant pathogens’ biocontrol agents.
... Alternatively, plant and microalgae-resulting peptides are recognized as selective, useful, nontoxic and well accepted when consumed, having a significant potentiality for utilization in functional aliments, drugs, and cosmetic products. Furthermore, due to the increasing issue of the antibiotic resistance against pathogenic bacteria, research has been targeted to exploring new antibacterial compounds derived from different natural environments [1][2][3][4]. Consequently, in recent years, growing scientific interest has been centered on the study of the bioactivity of extracts derived from plant species. In particular, the focus is on food plants included in the so-called traditional derived from plant species. ...
In the scenario of promising sources of functional foods and preventive drugs, microalgae and cyanobacteria are attracting global attention. In this review, the current and future role of microalgae as natural sources of functional foods for human health and, in particular, for oral health has been reported and discussed in order to provide an overview on the state of art on microalgal effects on human oral health. It is well known that due to their richness in high-valuable products, microalgae offer good anti-inflammatory, antioxidant, antitumoral, anti-glycemic, cholesterol-lowering, and antimicrobial activity. Moreover, the findings of the present research show that microalgae could also have a significant impact on oral health: several studies agree on the potential application of microalgae for oral cancer prevention as well as for the treatment of chronic periodontitis and different oral diseases with microbial origin. Thus, beneficial effects of microalgae could be implemented in different medical fields. Microalgae and cyanobacteria could represent a potential natural alternative to antibiotic, antiviral, or antimycotic therapies, as well as a good supplement for the prevention and co-adjuvant treatment of different oral diseases. Nevertheless, more studies are required to identify strains of interest, increase overall functioning, and make safe, effective products available for the whole population.
... Various components such as phycobilins, phenolic compounds, carotenoids, organic acids, sulphated polysaccharides spirulan and polyunsaturated fatty acids are present in blue green algae. Due to the high content of these metabolites, it has been reported for antioxidant (Wu et al, 2005), antibacterial (Falch et al, 1995;Mundt et al, 2001), antifungal (Macmillan et al, 2002) and even antiviral activities against Herpes simplex virus (HSV1), cytomegalovirus and influenza viruses (Mishima et al, 1998). Spirulina, the blue green alga is well known for its protein source. ...
... They can be used as thickeners, emulsifying agents and biosurfactants, with applications in the food and biomedical industry. Antibacterial (Mundt et al. 2001), antioxidant (Trabelsi et al. 2016) and anti-inflammatory properties (Xiao et al. 2018) have already been reported for EPS of cyanobacteria. ...
Abstract Arthrospira platensis is a cyanobacterium that is of great biotechnological interest, particularly for the food industry, as it possesses a high content of proteins, pigments, lipids and carbohydrates. Cyanobacteria produce extracellular polymeric substances (EPS), which are co-products of secondary metabolism that present thickening or gelling properties. A 3-level factorial design was used to study the combined effect of different nitrate concentrations and photon flux density (PFD) values to evaluate the biomass and EPS production of A. platensis. The best result in terms of biomass production was obtained under condition 6 (2 g L−1 NaNO3 and 600 μE m−2 s−1) yielding a concentration of 1.292 g L−1. However, condition 1 (0.25 g L−1 NaNO3 and 200 μE m−2 s−1) produced the greatest EPS yield (111 mg g−1), followed by condition 9 (2 g L−1 NaNO3 and 1000 μE m−2 s−1). FTIR analyses of EPS samples indicated the presence of carboxylate and sulfate functional groups, and rheological studies of the EPS at 5 and 10 g L−1 revealed a dilute solution behavior.
... They can be used as thickeners, emulsifying agents and biosurfactants, with applications in the food and biomedical industry. Antibacterial (Mundt et al. 2001 Arthrospira platensis, also called Spirulina platensis, is a lamentous blue-green cyanobacterium, belonging to the order Cyanophycea, division Cyanophyta (Manirafasha et al. 2018). Its biomass is used in human food due to its high protein content (approximately 70% of dry weight). ...
Arthrospira platensis is a cyanobacterium that is of great biotechnological interest, particularly for the food industry, as it possesses a high content of proteins, pigments, lipids and carbohydrates. Cyanobacteria produce extracellular polymeric substances (EPS), which are co-products of secondary metabolism that present thickening or gelling properties. A 3-level factorial design was used to study the combined effect of different nitrate concentrations and photon flux density (PFD) values to evaluate the biomass and EPS production of A. platensis . The best result in terms of biomass production was obtained under condition 6 (2 g.L ⁻¹ NaNO 3 and 600 μE.m ⁻² .s ⁻¹ ) yielding a concentration of 1.292 g.L ⁻¹ . However, condition 1 (0.25 g.L ⁻¹ NaNO 3 and 200 μE.m ⁻² .s ⁻¹ ) produced the greatest EPS yield (111 mg.g ⁻¹ ), followed by condition 9 (2 g.L ⁻¹ NaNO 3 and 1000 μE.m ⁻² .s ⁻¹ ). FTIR analyses of EPS samples indicated the presence of carboxylate and sulfate functional groups, and rheological studies of the EPS at 5 and 10 g.L ⁻¹ revealed a dilute solution behavior.
... Antimicrobial effects from Cyanobacterial aqueous and organic solvent extracts are visualized in bioassays using selected microorganisms as test organisms [5,6]. Cyanobacteria from local habitats seem to be a source of potential new active substances that could contribute to reduction of the number of bacteria, fungi, viruses and other microorganisms [7]. In the present work cyanobacteria of Thanjavur have not yet been studied for antimicrobial activity and little work has been done to screen cyanobacteria isolated from paddy-fields with regard to their production of bioactive compounds. ...
The three cyanobacterial species were isolated from Paddy-fields in the Poondi village, Thanjavur Dt., Tamil Nadu, India and cultured in BG11 media. Based on their growth characteristic, three species namely Oscillatoria laete-virens (Gronan) Gomont. Nostoc calcicola and Phormodium tenue were selected for antifungal and antibacterial assay against the pathogenic bacteria such as Citrobacter divergens, Escherichia coli (MTCC 3221), Klebsiella pneumoniae (MTCC 3384), Staphylococcus aurues (MTCC 3160) and Serratia marcescens (MTCC 3124) and the pathogenic fungus such as Aspergillus flavus (MTCC 1973), Aspergillus fumigatus (MTCC 3002), Aspergillus niger (MTCC 1344), Candida albicans (MTCC 3017), Rhizobus sp. The experiments for the inhibition activity on pathogenic bacterial and fungal strains were carried out at different concentration levels (25, 50 and 100 mg) of crude extract of three species of Cyanobacteria. Among the three cyanobacterial species extracts, Phormodium tenue showed the maximum inhibition (62 mm) against Serratia marcescens compared to other species whereas, the maximum antifungal activity (44 mm) was recorded in Phormodium tenue against Aspergillus flavus.
... Since ancient times the use of algae as food have been exhibited in various parts of the world such as Mexico, China, North America, India, Japan, Peru, and others. These Cyanobacteria have been earlier documented for their association with greater morphological, physiological and structural diversity which is a prerequisite for adaptation in a wide range of environment (Mundt et al., 2001). Within cyanobacterial phyla photosynthesis not only serves to be an ef icient phenomenon for reducing atmospheric carbon dioxide (Yun et al., 1997) but is also related with production of metabolites having signi icant economic and scienti ic value (Lim et al., 2005). ...
Cyanobacteria represent the richest sources of phycobiliproteins with especial reference to C-phycocyanin (C-PC), which in turn holds exhaustive therapeutic implications. Screening of several cyanobacterial strains namely Anabaena sp., Nostoc muscorum, Cylindrospermum sp., Plectonema sp., Scytonema sp., Spirulina sp., Synechococcous sp. and Tolypothrix sp. was carried out for their C-PC producing capacity, however the produced quantity of C-PC varies greatly among different strains. Owing to the crucial role of different media constituents on productivity of C-PC the current study was designed to optimize most appropriate media composition for augmented CPC production by selected superior producer. 36 factorial central composite design (CCD) dependent response surface methodology (RSM) was utilized to estimate the important medium components attributed with influencing C-PC productivity. RSM analysis of five independent coded factors including Na2CO3, K2HPO4, NaNO3, citric acid and EDTA were analyzed preceded by recognition of efficient variables for algal components production by Plectonema sp. Investigation of results revealed that the eminent medium components were NaCO3 (0.4 g/L); NaNO3 (0.5 g/L); K2HPO4 (2.8 g/L); citric acid (0.08 g/L) and EDTA (0.01 g/L) respectively. The optimized combination yielded 0.5536 mg/ml of C-PC. The increment of C-PC yield is R-Sq = 88.2%. Thus, our study led to the recognition of critical nutritional component that can be used further for enhanced productivity of C-PC.
... In recent years, the antimicrobial activity of cyanobacteria has gained importance due to antibiotic resistance as a result of overusing antibiotics, which leads to an increase in the infection rate by these antibiotic-resistant microorganisms (Chauhan et al., 2010). Some strains of cyanobacteria produce intracellular and extracellular metabolites with diverse biological activities such as antibacterial and antifungal (Mundt et al., 2001). Anabaena is a multicellular, filamentous, freshwater cyanobacterium that can fix nitrogen into a bioavailable form via the oxygen-labile nitrogenase complex, which is protected from molecular oxygen in specialized non-photosynthetic, non-dividing cells called heterocysts (Videau and Cozy, 2019). ...
The purpose of this work was to research the impact of N2- fixing cyanobacterium Anabaena sp. supplementation in the diet or as a culture in the fishpond of Nile tilapia. The growth performance and chemical analysis of fish body were investigated before challenging with Aeromonas hydrophila (.A. hydrophila). While biochemistry of the serum, immunity, and health status of Nile tilapia were investigated before and after the challenge test. Oreochromis niloticus (monosex males) were randomly allotted into three groups, according to Anabaena supplementation in the fish diet or pond. Groups including, a control group was provided with the experimental diet without supplement, the AM (Anabaena meal) group was provided with the experimental diet enclosure Anabaena (15 g/100 g rations), and the A (Anabaena cultivated in the pond) group was provided with the experimental diet but Anabaena was cultivated in the pond. The results showed that both ways of Anabaena supplementation significantly (P ≤ 0.05) improved growth performance parameters and increased protein in body composition before A. hydrophila challenge compared with the control. On the other hand, the serum biochemical parameters and immunity status of Nile tilapia significantly (P ≤ 0.05) improved before and after experimental challenge.
... Upon tested various solvents for the strains of Cylindrospermum majus, Oscillatoria, Calothrix gracilis, and Nostoc, n-hexane solvent restrained these microbial clusters at the concentration of 100 µg/ml, and when experienced distinctive extracts for the cultures such as Pseudanabaena catenata, Anabaena variabilis, and Gloeocapsa caldariorum, menthanol extract repressed the microbial growth of Bacillus subtilis with the concentration extend from 1.4 to 70 µg/ml. [57]. The Limnothrix redekei also inhibits the growth of Staphylococcus aureus and Micrococcus flavus with the concentration of 50/100 µg of the isolated substances per paper disk. ...
Water is an absolutely required resource for life nourishment especially for the purpose of drinking, domestic and farming. People in various part of the world are under prodigious threat due to unenviable changes in the physical-chemical and biological properties of an ecosystem. Due to anthropogenic causes like industrialization, the use of fertilizers and urbanization leads to highly polluted water bodies that include fresh and brackish water. These changes influence the harmful growth of cyanobacteria that is blue green algae. cyanoHABs (Cyanobacterial Harmful Algal Blooms) became a worldwide threat to drinking and recreational purpose due to its adopting nature according to the temperature fluctuations. In this study, a basic introduction to cyanotoxins as well as the entanglement of public health that includes route of exposure health effects and the pervasive impact of cyanotoxins and alleviation efforts in the waterbodies along with that the toxicosis. Cyanobacterial toxins such as hepatotoxicosis, neurotoxicosis, gastrointestinal disturbances respiratory and allergic reactions were reviewed. Their detection process and the treatment techniques with various physicochemical methods and bioassay methods were also reviewed.
... In one of the study antifungal activity the strains of cyanobacteria belonging to family Nostaceae, Microchaetaceae and Scytonematacaea were isolated from the Argentinian paddy fields, against Staphylococcus aureus and C. albicans was reported 33 . In Iran 150 strains of cyanobacteria were isolated out of which, 21 showed significant in vitro antibacterial activities and 13 of them had antifungal effect with the proportion of the isolates ...
In this pilot study, Zarrouk media was optimized in terms of biomass production and metabolites for the culture growth of, Spirulina species; Spirulina maxima and Spirulina platensis and their extract were tested against a nosocomial fungal species Candida albicans (C. albicans) to explore anticandidal activity. The corresponding growth and metabolite was measured in terms of turbidity, chlorophyll, carotenoid and protein content. The culture was harvested by centrifugation and extracted with 75% methanol by freeze thaw method. Supernatant was collected, evaporated to dryness and stored at-20 0 C. Anticandidal activities were assessed based on the agar-well diffusion method. The lawn of C. albicans was maintained at 1.5×10 5 CFU/ml on Sarbourd dextrose (SD) agar plates under sterile conditions. The plates were dried at 37 0 C for 30 minutes. Wells of 6mm diameter ware created by using sterile agar borer. The dried supernatants were dissolute in normal saline (0.8% NaCl) and poured in each well (100 µl) control well carried 100µl normal saline. Poured wells were incubated for 18 hours at 37 0 C and after that measured the zone of growth inhibition. Anticandidal activity was found to be maximum in the dissolute of late stationary phase of S. maxima where in S. platensis dissolute were less effective. The study concludes that antifungal activity of Spirulina species should be explored on the basis of their metabolite structure and function is needed to develop an effective edible fungicide in near future.
... Cyanobacteria are one of the oldest organisms in the world and have spread to very large habitats including freshwater, sea, and land (Malathi et al. 2014;Mundt et al. 2001;Thajuddin and Subramanian 2005). In recent years, the metabolites and the biomass produced by Cyanobacteria are gaining attention as new commercial sources. ...
The information available on microalgae-sourced compounds, especially antibiotics and other bioactive compounds, and their potential commercial applications is still insufficient. In this study, antibacterial activity, metabolites, and molecular characterization of Phormidium autumnale, which was isolated from samples collected from different natural freshwater sources in Ankara, Turkey, were investigated. Sequencing results of 16s rDNA confirmed the molecular identification of P. autumnale by 99%. It was determined that the peak values of some phenolic compounds and cyclic peptides were consistent with the 1653–1389 cm−1 band regions in the FTIR spectra of the species. The antibacterial activities of P. autumnale cyanobacteria (CBA) extracts that were obtained by using different solvents were tested on Escherichia coli, Staphylococcus epidermidis, methicillin-resistant (MR) Staphylococcus aureus, Streptococcus agalactiae, and Enterococcus faecalis by using a disc diffusion method. Also, the minimum inhibition concentration (MIC) and antimicrobial indexes of all extracts were determined. It was found that P. autumnale methanol extracts showed antibacterial activity on all test bacteria, whereas acetone extracts showed effects only on E. coli. For the inhibition of MR S. aureus, the control methanol extract was found to give very similar results to those exhibited by the control antibiotics, and the antimicrobial index results were determined to be 58.7–67.5%. According to the results of the analysis of methanol extract, gentisic acid, vanillic acid, 4-hydroxybenzoic acid, p-coumaric acid, and catechin (especially phenolic compounds) were determined to be the active compounds. It can be concluded that P. autumnale is an alternative to current commercial applications as an antibacterial agent in phytotherapy.
... It is also recommended that to obtain highest amount of cell biomass, and intracellular and extracellular peptides, there is need to make some changes in the recipe of BG-11 and time to harvest N. spumigena KAC 66 cultures. The role of toxin and other bioactive peptides by cyanobacteria is still unclear, potential use as signalling compounds or for defence against microorganisms that feed on cyanobacterial strains (Mundt et al. 2001). There is some information available on the fate of toxins released in surrounding medium. ...
Blooms of the cyanobacterium Nodularia spumigena occur regularly in the Baltic Sea typically producing a wide range of bioactive peptides including the hepatotoxin nodularin (NOD), spumigins, anabaenopeptins and nodulopeptins (molecular weights: 917, 901 and 899 Da). This study reports the production of intracellular and extracellular NOD and nodulopeptin 901 (the major secondary metabolites), at various nitrate and phosphorus concentrations produced by N. spumigena KAC 66 which had been originally isolated from the Baltic Sea. The growth was observed by cell biomass and intracellular and extracellular peptides monitored by high-performance liquid chromatography with photodiode array and mass spectrometry (HPLC-PDA-MS). In the present work, it was found that high concentrations of nitrate and phosphorus have a considerable effect on biomass and toxin levels of N. spumigena. In common with many studies, the maximum amount of NOD was retained within the cells during 5 weeks of growth. In contrast, as much as ~ 40% of nodulopeptin 901 was excreted into the medium throughout the duration of experiments. At 6.5 and 3.5 mg L⁻¹ nitrate, the maximum concentrations of peptide per unit biomass was 1.78 ng NOD (in week 4) and 1.42 ng nodulopeptin 901 μg⁻¹ (in week 3) were detected. However, the high concentrations of both peptides were produced in the absence of nitrate. The phosphate experiment indicated growth, and peptide production was dependent on availability of phosphorus. At 0 mg L⁻¹ of phosphate, an increased amount of intracellular (502.4 ng μg⁻¹ biomass) nodulopeptin 901 was recorded. This report evaluates the effect of nutrients on the production of biomass and toxins, which may predict the formation and control of blooms of N. spumigena in the Baltic Sea. It also provides information to improve the growth conditions to produce high biomass and toxins under suitable conditions, which may be helpful in the research. The results from the current study will also be helpful to predict about possible blooms of N. spumigena in the Baltic Sea with reference to increase or decrease in nitrate and phosphate concentrations.
... In recent years, the occurrence of harmful algal blooms has increased due to eutrophication. As cyanobacteria are often present, they can accumulate in the food chain leading to animal poisoning and risks to human health (Mata et al., 2010;Mundt et al., 2001). Thus, research is also focused on removing such species from the environment by environmentally attractive means. ...
The majority of algal cells can interact with a wide range of nano-and microparticles. Upon interaction the modified cells usually maintain their viability and the presence of foreign material on their surfaces or in protoplasm can provide additional functionalities. Magnetic modification and labeling of microalgal biomass ensures a wide spectrum of biotechnological, bioanalytical and environmental applications. Different aspects of microalgal cell magnetic modification are covered in the review, followed by successful applications of magnetic algae. Modified cells can be employed during their harvesting and removal, applied in toxicity microscreening devices and also as efficient adsorbents of different types of xenobiotics.
... Cyanobacteria have a significant attraction as natural source of bioactive molecules with a broad range of biological activities [2]such as antibiotics, antiviral, antitumourals, antioxidant and anti-inflammatory compounds [3]. Cyanobacteria have been regarded as a good candidate for drug discovery with applications in agriculture [4], industry [5] and especially in pharmaceuticals [6]. Researchers have been claimed that consumption of cyanobacteria are beneficial to health due to its chemical composition including compounds like essential amino acids, vitamins, natural pigments and essential fatty acids, particularly γ-linolenic acid, a precursor of the body's prostaglandins. ...
The aim of the study was to investigate the anti-pathogenic activities of selected cyanobacteria isolated from freshwater bodies of Sri Lanka.
... These organisms are an excellent sources for investigation by the ecologists, physiologists, biochemists, pharmacists and molecular biologists. Biologically active substances were extracted from cyanobacteria [7,8]. Microalgae have meanwhile been found to produce antibiotics: a large number of microalgal extracts and/or extracellular products have proven antibacterial, antifungal, antiprotozoal and antiplasmodial [9,10]. ...
Cultures of the blue green algae (cyanobacteria) Anabaena circinalis were identified and isolated from freshwater and their antimicrobial effect was studied. The extract of A. circinalis was tested to investigate its efficiency against four bacterial strains (Achromobacter xylosoxidans, Staphylococcus aureus, Escherichia coli, Shigella dysenteriae. Antimicrobial test was determined by disk diffusion method. Different concentrations of algal extracts (25, 50, 75 and 100%) were tested. Results showed that the highest level of antimicrobial activity was recorded against S. dysenteriae at 100% concentration followed by 25% extract concentration against the same bacteria. In comparison with two antibiotics Ampicillin (AMP), oxacilina (OXA), AMP was the most effective on S. dysenteriae followed by OXA. S. aureus and E. coli were resistant to both antibiotics while they were sensitive to A. circinalis extracts at even at low concentrations (25% and 50%). Thus the present study revealed that extracts of A. circinalis extract is would be a promising natural source, for novel antibiotics, hence worthy for more investigations.
... Cyanobacteria have proven to be an extremely valuable source of novel bioactive agents (Jaki et al., 2000). Cyanobacteria produce a variety of secondary metabolites with cytotoxic (Harrigan et al., 1998;Luesch et al., 2000), antiviral (Larsen et al., 1994;Hayashi & Hayashi, 1996), antiplasmodial (Papendorf et al., 1998), algicide (Papke et al., 1997), immunosuppressive (Koehn et al., 1992), antibacterial (Falch et al., 1995;Ishida et al., 1997;Mundt et al., 2001), and antifungal (Kajiyama et al., 1998;Jaki et al., 2001;MacMillan et al., 2002) activities. Screening of cyanobacteria for antibiotics and other pharmacologically active compounds has recently received considerable attention as a new source of novel bioactive natural products (Browitzka, 1995). ...
... Hence, the extract is recommended to treat infections like Bacillus subtilis and S. typhi. Generally Chlorella were found to be effective against only on two pathogen and the anti bacterial activities was found to be dose dependent the phenomenon was in agreement with the findings of [32]. After being isolated, they were confirmed through morphological structures of microalgae C. vulgaris on cultivation of two different Medias. ...
The three marine microalgae (Chlorella vulgaris, Spirulina platensis and Nannochloropsis bacillaris) were collected from Vellar estuary, South east coast of India. These three microalgae were cultivated in respective media and estimated their biochemical composition and antibacterial activity. Simultaneously, these cultures were cultivated in flask containing 500 ml of respective media at lab condition for a period of one month and their growth, pH, biomass and CO 2 fixation and carbon content were determined. Based on the growth rate, the pH of three microalgae in media was observed at lab condition. During maximum growth and biomass, the pH was found to be ranged between 9 & 11 for Spirulina platensis, 7 & 9 for Chlorella vulgaris; 8 & 9 for Nannochloropsis bacillaris. Spirulina platensis and Chlorella vulgaris reached maximum growth rate whereas Chlorella vulgaris and Spirulina platensis showed maximum biomass produced. Chlorella vulgaris and Spirulina platensis attained maximum biomass in media at lab condition, also fixed highest level of carbon dioxide in media but they did not produce maximum biomass, though the growth of Nannochloropsis bacillaris were found high in media at lab condition. Among the three microalgae, Chlorella vulgaris and Spirulina platensis produced highest biochemical compounds. Hence Chlorella vulgaris and Spirulina platensis were selected as efficient microalgae for antibacterial activity against human pathogen. This study revealed that certain green algae and blue green microalgae having high growth, pH, CO 2 fixation, carbon content and biochemical composition paves the way for pharmaceutical activity. Antibacterial activity was evaluated for Chlorella and Spirulina with their potential health benefits.
... Screening of cyanobacteria for antibiotics and other pharmacologically active compounds, has received ever-increasing interest as a potential source for new drugs (Kaushik and Chauhan, 2009;Rastogi and Sinha, 2009). Cyanobacteria from local habitats seem to be a source of potential new active substances that could contribute to reduction of the number of bacteria, fungi, viruses and other microorganisms (Mundt et al., 2001). The growing concern about Antibiotic resistant in patients with bacterial infections has recently led to the development of natural antimicrobials to control pathogens and spoilage bacteria (Friedman et al., 2002). ...
Cyanobacterial secondary metabolites can be a good candidate for inhibition of many n pathogenic bacteria. The general objective of this study was test of antibacterial activity of aqueous and methanolic extract of cyanobacterium Synechococcus elongatus against a number of pathogenic bacteria. In this experimental study, the cyanobacterium Synechococcus elongatus ISC 106 was obtained from the Algal culture collection of research institute of applied science, ACECR, Tehran, Iran. Disk diffusion method was used to study the effect of antimicrobial and broth microdilution method was used to determine the minimum inhibitory concentration (MIC). The results indicated that Methanolic extract of Synechococcus elongatus has no significant effect against tested bacteria. The results also clearly showed that aqueous extract of Synechococcus elongatus have significant antibacterial activity against most pathogenic bacteria; So that maximum antibacterial activity was against Staphylococcus aureus (PTCC 1112) which the average zone diameter around it was 26.33 Millimeters. Minimum inhibitory concentration of aqueous extract against most tested human pathogen bacteria was 125 mg/ml. It is concluded from this study that extracts of Synechococcus elongatus show antimicrobial activity against the human pathogenic bacteria used in the present investigation and antibacterial activity of aqueous extract of Synechococcus elongatus was more than Methanolic extract of Synechococcus elongatus Improvement knowledge of the composition, analysis, and the properties of these cyanobacteria with respect to antimicrobial compounds would assist in efforts for the pharmaceutical application.
... Thraustochytrids can act as bacterivores or bacterial feeders (Raghukumar 1992;Atienza 2012;Chang 2013) and many previous reports have demonstrated antibacterial activity of several microalgae (e.g., Abedin and Taha 2008;Martins et al. 2008). The potential of antibacterial agent production by microorganisms as a defensive mechanism could be exploited as a source of new bioactive compounds (Mundt et al. 2001). Antagonistic potential can be used in aquaculture sector as these strains can be used as probiont/ live agent to protect the host against pathogens and control pathogenic bacterial proliferation in aquaculture systems. ...
... Thraustochytrids can act as bacterivores or bacterial feeders (Raghukumar 1992;Atienza 2012;Chang 2013) and many previous reports have demonstrated antibacterial activity of several microalgae (e.g., Abedin and Taha 2008;Martins et al. 2008). The potential of antibacterial agent production by microorganisms as a defensive mechanism could be exploited as a source of new bioactive compounds (Mundt et al. 2001). Antagonistic potential can be used in aquaculture sector as these strains can be used as probiont/ live agent to protect the host against pathogens and control pathogenic bacterial proliferation in aquaculture systems. ...
Among several sustainable resources, marine heterotrophic microorganisms have gained much interest for various commercial applications owing to their potential to produce high quantities of polyunsaturated fatty acids. Above 70% of the globally produced fish oil is utilised for aqua feed formulations. Intense research is being carried out to find suitable alternatives to fish oil. Oleaginous protists are being explored as a promising substitute to fish oil and also for various high-value-added products. However, characterisation and utilisation of these unique protists remain underexplored in many countries including India and this prompted us to screen and isolate these heterotrophic microorganisms capable of producing PUFAs. In this study, 11 strains of heterotrophic thraustochytrid capable of producing significant quantities of polyunsaturated fatty acids were successfully isolated from different mangrove habitats along the southwest coast of India. Morphological characterisation along with molecular identification revealed that these strains showed close similarity to Aurantiochytrium spp. of the family Thraustochytridae. They are able to produce 7–11 g of dry biomass per litre of culture. Their fatty acid content was up to 12% (wt/wt) of biomass and GC analysis confirmed that these protists can accumulate docosahexaenoic acid as high as 22–60% of the total fatty acids. Their enzymatic activity, tolerance to various abiotic stress factors and antagonistic potential against vibrios are also described. These heterotrophic protists can antagonise aquaculture pathogens and act as an excellent source of docosahexaenoic acid that indicates their potential as a sustainable alternative to fish oil.
... Bioassay-guided fractionation is a successful strategy in the isolation and discovery of novel compounds [27][28][29][30][31]. To address toxin production, several assays can be used. ...
Marine sponges and cyanobacteria have a long history of co-evolution, with documented genome adaptations in cyanobionts. Both organisms are known to produce a wide variety of natural compounds, with only scarce information about novel natural compounds produced by cyanobionts. In the present study, we aimed to address their toxicological potential, isolating cyanobacteria (n = 12) from different sponge species from the coast of Portugal (mainland, Azores, and Madeira Islands). After large-scale growth, we obtained both organic and aqueous extracts to perform a series of ecologically-relevant bioassays. In the acute toxicity assay, using nauplii of Artemia salina, only organic extracts showed lethality, especially in picocyanobacterial strains. In the bioassay with Paracentrotus lividus, both organic and aqueous extracts produced embryogenic toxicity (respectively 58% and 36%), pointing to the presence of compounds that interfere with growth factors on cells. No development of pluteus larvae was observed for the organic extract of the strain Chroococcales 6MA13ti, indicating the presence of compounds that affect skeleton formation. In the hemolytic assay, none of the extracts induced red blood cells lysis. Organic extracts, especially from picoplanktonic strains, proved to be the most promising for future bioassay-guided fractionation and compounds isolation. This approach allows us to classify the compounds extracted from the cyanobacteria into effect categories and bioactivity profiles.
... No Brasil, os episódios de florações são favorecidos pelo precário sistema de tratamento e fiscalização dos efluentes de esgoto residencial e industrial, aliado, geralmente, às características edafo- climáticas (níveis altos de radiação solar e ventos fracos, águas com temperatura amena e pH) propícias ao crescimento intenso de cianobactérias durante todo o ano ( CARNEIRO, 2005 As cianobactérias também vêm sendo estudadas para uso no ramo alimentício, farmacêutico e agrícola; pelo seu alto valor nutritivo, possível potencial farmacológico e pela influência que exercem sobre a fertilidade de solos e águas (REPKA et al. 2004;GOMES et al., 2009). Além das toxinas, um grande número de substâncias ativas com potencial biológico antibacteriano, antiviral, fungicida, de inibição de enzimas, com atividade imunossupressora, efeitos citotóxicos e algicida foram isolados a partir de cianobactérias (MUNDT et al., 2001). A identificação desses compostos e o estabelecimento de seus efeitos constituem uma nova fonte de produtos naturais chamados cianopeptídeos Finalmente, as ciclamidas ( fig. ...
The development of multiple-drug-resistant pathogens has prompted medical research toward the development of new and effective antimicrobial therapies. Much research into novel antibiotics has focused on bacterial and fungal compounds, and on chemical modification of existing compounds to increase their efficacy or reactivate their antimicrobial properties. In contrast, cyanobac-teria have been relatively overlooked for antibiotic discovery, and much more work is required. This may be because some cyanobacterial species produce environmental toxins, leading to concerns about the safety of cyanobacterial compounds in therapy. Despite this, several cyanobacterial-derived compounds have been identified with noteworthy inhibitory activity against bacterial, fungal and protozoal growth, as well as viral replication. Additionally, many of these compounds have relatively low toxicity and are therefore relevant targets for drug development. Of particular note, several linear and heterocyclic peptides and depsipeptides with potent activity and good safety indexes have been identified and are undergoing development as antimicrobial chemotherapies. However, substantial further studies are required to identify and screen the myriad other cyanobacterial-derived compounds to evaluate their therapeutic potential. This study reviews the known phytochemistry of cyanobacteria, and where relevant, the effects of those compounds against bacterial, fungal, protozoal and viral pathogens, with the aim of highlighting gaps in the literature and focusing future studies in this field.
Cyanobacteria, an abundant source of natural products with a broad diversity of secondary metabolites, have emerged as a novel resource for the progression of synthetic analogs. Due to the rise of antibiotic resistance, there is a need for new medications and cyanobacteria-derived compounds have shown promising important alternatives for new therapeutics. These secondary metabolites are produced through nonribosomal peptide synthetase (NRPS), polyketide synthase (PKS), and mainly through mixed NRPS-PKS enzymatic systems. Current research is focused on the exploitation of cyanobacteria for the production of bioactive metabolites. Screening of cyanobacteria for pharmaceutically active compounds has received increasing attention; however, limited knowledge is available on biosynthetic mechanisms that would enhance the drug discovery process and culture-based production of desired metabolites. Overall, there is a promising outlook that cyanobacterial secondary metabolites will become alternatives for the development of new medications in a near future with enhanced pharmacological and pharmacokinetic properties.
Intensive use of fossil-based energy sources causes significant environmental problems on a global scale. Researchers have been working for several decades to find alternative energy solutions to fossil fuels. Algae are a renewable energy source, with high potential for increasing scarce resources and reducing environmental problems caused by fossil fuel use. Algal Biotechnology for Fuel Applications gives the reader a comprehensive picture of the industrial use of algae for generating power. This book informs readers about the existence of alternative species to the currently used algae species for biofuel production, while also explaining the methods and current concepts in sustainable biofuel production. Key Features - Fifteen chapters covering topics on commercial algae species and algal biofuel production. - Covers anaerobic biotechnology and basic biofuel production from thermal liquefaction - Covers biodiesel production and algal biofuel characterization - Introduces the reader to applied microbial fuel cell technology and algae cultivation methods - Provides concepts about ecological engineering - Covers microalgae culture and biofuel production techniques - Explains the importance of catalysts - Explains the economic evaluation of algae fuel production technology This reference is essential reading for students and academics involved in environmental science, biotechnology, chemical engineering and sustainability education programs. It also serves as a reference for general readers who want to understand the ins and outs of algal biofuel technology.
Intensive use of fossil-based energy sources causes significant environmental problems on a global scale. Researchers have been working for several decades to find alternative energy solutions to fossil fuels. Algae are a renewable energy source, with high potential for increasing scarce resources and reducing environmental problems caused by fossil fuel use. Algal Biotechnology for Fuel Applications gives the reader a comprehensive picture of the industrial use of algae for generating power. This book informs readers about the existence of alternative species to the currently used algae species for biofuel production, while also explaining the methods and current concepts in sustainable biofuel production. Key Features - Fifteen chapters covering topics on commercial algae species and algal biofuel production. - Covers anaerobic biotechnology and basic biofuel production from thermal liquefaction - Covers biodiesel production and algal biofuel characterization - Introduces the reader to applied microbial fuel cell technology and algae cultivation methods - Provides concepts about ecological engineering - Covers microalgae culture and biofuel production techniques - Explains the importance of catalysts - Explains the economic evaluation of algae fuel production technology This reference is essential reading for students and academics involved in environmental science, biotechnology, chemical engineering and sustainability education programs. It also serves as a reference for general readers who want to understand the ins and outs of algal biofuel technology.
Intensive use of fossil-based energy sources causes significant environmental problems on a global scale. Researchers have been working for several decades to find alternative energy solutions to fossil fuels. Algae are a renewable energy source, with high potential for increasing scarce resources and reducing environmental problems caused by fossil fuel use. Algal Biotechnology for Fuel Applications gives the reader a comprehensive picture of the industrial use of algae for generating power. This book informs readers about the existence of alternative species to the currently used algae species for biofuel production, while also explaining the methods and current concepts in sustainable biofuel production. Key Features - Fifteen chapters covering topics on commercial algae species and algal biofuel production. - Covers anaerobic biotechnology and basic biofuel production from thermal liquefaction - Covers biodiesel production and algal biofuel characterization - Introduces the reader to applied microbial fuel cell technology and algae cultivation methods - Provides concepts about ecological engineering - Covers microalgae culture and biofuel production techniques - Explains the importance of catalysts - Explains the economic evaluation of algae fuel production technology This reference is essential reading for students and academics involved in environmental science, biotechnology, chemical engineering and sustainability education programs. It also serves as a reference for general readers who want to understand the ins and outs of algal biofuel technology.
Cyanobacterial algae Gloeocapsa and Phormidium and the green algae Ankistrodesmus and Chlorella were used for this study Molecular diagnosis was made for Phormidium and Ankistrodesmus, the results showed that the algae Phormidium showed a 92% match of the genome with the alga Cyanobacteria Phormidium sp. Ru5-34, Ankistrodesmus, showed 88% genome match was found with the green alga Ankistrodesmus falcatus.
Two different mediums were used for algal growing, modified Chu10 and modified EChu10, for a growth period of seventeen days for all algae except for Phormidium, in which the growth was for the twentieth day.. A difference in growth was noticed, in modified Chu10 it was increased till the Fifteenth day then it began to decrease. In modified EChu 10, it was noticed the wave of growth among these algae in different days, whereas in Phormidium the growth was best at the 10th day and then decreased at the 20Th day in both media. The ethanol and the phenol (ethylene acetate) extracts were prepared and phenolic compounds (Gallic acid, Phenol and Tannic acid) were diagnosed in the phenolic extract via TLC technique. Also a number of phenolic compounds (Gallic acid, Keampferol, Qurcetine, Rutin, Catechine, Apigenin and Coumarin) were diagnosed for algae via HPLC and the compound (Qurcetine) recorded the highest percentage in the raw ethanol extract of the algae Ankistrodesmus (20.9%), and in the phenolic extract of the algae (Chlorella) (16.9%), thus, green algae outmatched the cyanobacteria. Acetone extract, ether extract (beta- carotene) and methanol extract were prepared for Phormidium and Ankistrodesmus algae, and β– carotene pigment was diagnosed in the ether extract via TCL and HPLC in both the two algae. The highest ratio of the pigment was in the acetone
A
extract followed by the ether extract and finally came the methanol extract. Green algae exceed the cyanobacteria in all extracts and their ratio in the ether extract in the two above mentioned algae were (63.5،7.460%), respectively. The antibacterial activity of all extracts against bacteria (Staphylococcus aureus ،Esherichia coli ،Proteus mirabilis ،pneumoniae Klebsiell ،Pseudomonas aeruginosa), were studied and it was noticed the inactive of the ethanol and acetone extracts of algae against all types of bacteria while the phenolic and ether extracts showed evident efficiency. The most significant inhibition was of the phenolic extract of the algae Phormidium against the bacteria Klebsiell pneumoniae with a diameter of (32 mm). The efficiency of these extracts was also studied against the fungi (Fusarium solani ،Alternaria alternata،Candida albicans) and the efficiency of the extracts was similar to their efficiency against bacteria except for the ethanol extracts of Phormidium and Ankistrodesmus which were effective against the fungi Alternaria alternate with a diameter of (13, 17 mm) respectively, and the Gloeocapsa phenolic extract had the highest activity against Alternaria alternata, with an inhibition diameter of (42 mm). The effect was studied of adding the amino acid tyrosine (Try) and phenylalanine (Phe) on the content of phenols in algae (internal content= Enddocellular) and the concentration of phenols in the cultivation medium Chu10 (external secretion=Exocellular), as well as the variation of the concentration of phenols according to the concentration, the type of the added amino acid to the cultivation medium and the type of algae. The highest internal content with a concentration of (0.5 μg/ml) was of Chlorella in the medium to which amino acid (Phe 0.5 / liter) was added and at the 24th day, while the highest concentration of phenol for the external
B
excretion of Gloeocapsa algae was (0.47 μg/ ml) in a medium to which amino acid (Try 1g/liter) was added
Cyanobacteria are one of the oldest creatures on earth, originated 3.5–3.3 billion years ago, and are distributed all over the world, including freshwater ponds and lakes, hot springs, and polar ice, especially in tropical and subtropical marine locations. Due to their large multimodular non-ribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) biosynthetic machinery, cyanobacteria have represented a significant new source of structurally bioactive secondary metabolites. Moorea as a prolific producer have yielded lots of natural products with a variety of bioactivities such as highly cytotoxicity, anticancer activity, ion channel blocking activity, brine shrimp toxicity and other activities. Some of secondary metabolites have been identified as potential lead compounds for the development of anticancer agents. In this review, a total of 111 bioactive marine cyanobacterial secondary metabolites from the genus Moorea, published in the 54 literatures in past 26 years and some synthetic analogues, are discussed with emphasis on their structures and biological activities.
This paper presents a strategy for isolation, identification and evaluation of microalgae strains synthesizing biologically active compounds (BAC) with antimicrobial activity against food-borne and other pathogens. Water samples containing microalgae were initially submitted to the enrichment process, followed by standard procedure for obtaining pure culture. Purified DNA from the microalgae isolates was used for sequencing the amplified 18S rDNA genomic region, which resulted in the identification of Poterioochromonas malhamensis, Chlorella sp., Micractinium sp., Tetradesmus sp. and Desmodesmus sp. All isolated strains were cultivated in 1-L flat-plate PBRs, with the Poterioochromonas malhamensis being the only one to show antibacterial activity in agar diffusion assay. Further, PPEQ-01strain was cultured under different types and scales of PBR, intensity and spectrum of the incident light, in order to study and prove the antibacterial potential of the strain. Ethanolic and methanolic supernatants, or hydrophilic and methanolic extracts produced from biomass cultivated in different conditions led to formation of bacterial growth inhibition halos around the impregnated disks used in the agar diffusion test. The hydrophilic extract, obtained from biomass cultured under green illumination, exhibited stronger activity against all tested pathogenic bacteria as compared to the other extracts. The results obtained with the new isolated Poterioochromonas malhamensis strain proved efficiency of the innovative complex approach applied to BAC aiming the identification of microalgae that present antimicrobial activity.
Ethanol, methanol and aqueous extracts of the algal plant Sprirulina plantensis were evaluated for their antimicrobial activity against four types of Gram positive bacteria namely Staphylococcus aureus, Streptococcus pneumoniae, Bacillus cereus and Enterococcus faecalis. Six types of Gram negative bacteria were also tested. They were Pseudomonas aureginosa, Proteus vulgaris, Salmonella typhi, Enterobacter cloacae, Klebsiella pneumoniae and Escherichia coli. Four species of Candida sp. were also bioassayed their response when the extracts were used. All of these algal extracts irrespective of their types inhibited the growth of all microbes to varying degrees. Methanol extract showed strong and superior antibacterial activity against all bacterial strains especially with regard to Gram positive bacteria (Staphylococcus aureus, Streptococcus pneumoniae, Bacillus cereus and Enterococcus faecalis) as compared to ethanol or aqueous extracts. Less or no activity was observed against Penicillium sp. (5±0.41) and Candida parapsilosis (08±0.44) in aqueous extract with 50mg/mL concentration. The minimum inhibitory concentration value of ethanol and methanol extract ranged between 5-100mg/mL for different strains tested. It was clearly noticed that Spirulina had a broad spectrum activity against bacteria and fungi in all the extracts tested. These findings support the traditional use of Spirulina as probiotic agent or in the treatment of different infections in area.
Introduction:
Due to the increase in bacterial resistance to common antibiotics, a tendency has grown toward using
natural compounds with antimicrobial activity. Meanwhile, many bacterial species show multi- or panresistant
phenotypes. Many of these multidrug resistant (MDR) bacteria can cause life-threatening
infections, being a major concern both in the hospital and in the community. Therefore, in this study,
we investigated the antimicrobial properties of cyanobacteria Oscillatoria sp.
Material and Methods:
The antimicrobial effect of cyanobacteria of Oscillatoria was investigated at concentrations of 50
mg/ml. The antimicrobial properties of cyanobacteria extract supernatant was investigated in well
diffusion agar. Moreover, the minimum inhibitory concentration (MIC) was calculated against human
pathogenic bacteria such as S. aureus, B. subtilis, P. aeruginosa and E. coli.
Results:
We observed the highest antimicrobial activity against E. coli with inhibition zone diameter of 24 mm
and the lowest antibacterial effect against P.aeruginosa with inhibition zone diameter of 14 mm. In
addition, the minimum inhibitory concentration of Oscillatoria extract against E. coli and Pseudomonas
was documented in 3.125 and 12.5 mg/mL, respectively.
Conclusion:
Our results indicated that the methanolic extract of Oscillatoria had a proper antimicrobial activity
against human pathogens and this inhibiotion was dose-dependent.
Keywords: Oscillatoria, Human Pathogens, Antimicrobial
Several species of blue-green algae (cyanobacteria) in saline and fresh waters produce toxins which cause illness or death to domestic animals, birds and fish. The extent of this hazard in Europe has been surveyed and the presence of toxic blooms has been found to be greater than previously estimated. Reviews the current understanding of blue-green algal toxicity, identifies the gaps in this knowledge and recommends areas for future studies.-from Authors
A status report of a program initiated in early 1981 to evaluate extracts of cultured blue-green algae for pharmacological activity and to isolate and identify active agents i s presented. Novel macrolides and nucleosides, for example, have been shown to be responsible for the cytotoxic and fungicidal activities of many blue-green algae belonging to the Scytonemataceae. In the last two years this program has been expanded to include studies on marine animals that harbor symbiotic algae. Macrolides, for example, have been found to account for the potent cytotoxicity of an Indonesian sponge Hyattella sp. and a Guamanian tunicate Lissoclinum patella.
Studies were conducted on the eutrophic Mikołajskie Lake in the Mazurian Lake District. Over the period of investigation three maxima of the development of phytoplankton were observed: in the spring, summer and autumn. During the algal blooms the total number of bacteria in the lake strongly decreased and was between several and a dozen time smaller than between blooms. The decrease in the total number of bacteria in water and the elimination of gram positive bacteria during the algal blooms is most probably caused by the production by the algae of substances inhibiting bacterial development.
It has been found that during algal blooms in an eutrophic lake occurs elimination and selection of bacteria. In this period a strong decrease in number of bacteria in the water was observed. The effect of the antibacterial substances produced by algae on the growth and respiration of bacteria isolated from the lake was investigated. The bloom forming algae were found to produce substances inhibiting the growth and respiration of Gram positive bacteria. Gram negative rods were resistant to the action of these substances. The algal substances inhibited also degradation of organic matter in the lake but only in the euphotic zone.
IL-4 has multiple biologic activities and it has been shown to have effects on B and T lymphocytes, mast cells, NK cells, and monocytes. We studied the influence of IL-4 on the expression of cell membrane determinants, in particular aminopeptidase-N (CD13) and Fc epsilon RIIb (CD23), on human peripheral blood monocytes. We compared the response of monocytes with the response of human alveolar macrophages and monocytic cell lines (U937 and THP1), as mature and more immature representatives of the mononuclear phagocyte system, respectively. A dose-dependent increase of the expression of CD13 Ag was observed when monocytes were cultured with IL-4. Kinetic analyses revealed that this induction was maximal after 2 to 3 days of culture and resembled the kinetics of IL-4-induced expression of Fc epsilon RIIb on monocytes. This IL-4-induced increase was absent when monocytes were cultured with IL-4 and an anti-IL-4 antiserum. Concomitantly, an IL-4-induced increase in leucine-aminopeptidase activity could be observed. Northern blot analysis showed that incubation of monocytes with IL-4 induced a marked increase in CD13 mRNA. Alveolar macrophages also exhibited an increase in CD13 Ag expression when exposed to IL-4. Surprisingly, IL-4 was unable to induce expression of Fc epsilon RIIb on alveolar macrophages. U937 and THP1 cells did not show an induction of CD13 Ag when cultured in the presence of IL-4. However, IL-4 did induce the expression of Fc epsilon RIIb on both cell lines, suggesting the presence of functional IL-4R. Our data demonstrate that IL-4 increases the expression of CD13 Ag on monocytes. This IL-4-induced increase can also be observed in more mature monocytic cells such as alveolar macrophages, but is absent in immature cells such as U937 or THP1 cells. This is functionally accompanied by an increase in leucine-aminopeptidase activity and may be part of the general activation of monocytes/macrophages by IL-4. In conclusion, the data suggest that IL-4 responsiveness, in particular the induction of CD13 Ag and Fc epsilon RIIb expression, may be dependent on the stage of maturation of monocytes/macrophages.
A novel trypsin-like protease associated with rat bronchiolar epithelial Clara cells, named Tryptase Clara, was purified to homogeneity from rat lung by a series of standard chromatographic procedures. The enzyme has apparent molecular masses of 180 +/- 16 kDa on gel filtration and 30 +/- 1.5 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. Its isoelectric point is pH 4.75. Studies with model peptide substrates showed that the enzyme preferentially recognizes a single arginine cleavage site, cleaving Boc-Gln-Ala-Arg-4-methylcoumaryl-7-amide most efficiently and having a pH optimum of 7.5 with this substrate. The enzyme is strongly inhibited by aprotinin, diisopropylfluorophosphate, antipain, leupeptin, and Kunitz-type soybean trypsin inhibitor, but inhibited only slightly by Bowman-Birk soybean trypsin inhibitor, benzamidine, and alpha 1-antitrypsin. Immunohistochemical studies indicated that the enzyme is located exclusively in the bronchiolar epithelial Clara cells and colocalized with surfactant. An immunoreactive protein with a molecular mass of 28.5 kDa was also detected in airway secretions by Western blotting analyses, suggesting that the 30-kDa protease in Clara cells is processed before or after its secretion. Proteolytic cleavage of the hemagglutinin of influenza virus is a prerequisite for the virus to become infectious. Tryptase Clara was shown to cleave the hemagglutinin and activate infectivity of influenza A virus in a dose-dependent way. These results suggest that the enzyme is a possible activator of inactive viral fusion glycoprotein in the respiratory tract and thus responsible for pneumopathogenicity of the virus.
Most antigenic peptides presented on major histocompatibility complex class I molecules are generated during protein breakdown by proteasomes, whose specificity is altered by interferon-gamma (IFN-gamma). When extended versions of the ovalbumin-derived epitope SIINFEKL are expressed in vivo, the correct C terminus is generated by proteasomal cleavage, but distinct cytosolic protease(s) generate its N terminus. To identify the other protease(s) involved in antigen processing, we incubated soluble extracts of HeLa cells with the 11-mer QLESIINFEKL, which in vivo is processed to the antigenic 8-mer (SIINFEKL) by a proteasome-independent pathway. This 11-mer was converted to the 9-mer by sequential removal of the N-terminal residues, but surprisingly the extract showed little or no endopeptidase or carboxypeptidase activity against this precursor. After treatment of cells with IFN-gamma, this N-terminal trimming was severalfold faster and proceeded to the antigenic 8-mer. The IFN-treated cells also showed greater aminopeptidase activity against many model fluorogenic substrates. Upon extract fractionation, three bestatin-sensitive aminopeptidase peaks were detected. One was induced by IFN-gamma and was identified immunologically as leucine aminopeptidase (LAP). Purified LAP, like the extracts of IFN-gamma-treated cells, processed the 11-mer peptide to SIINFEKL. Thus, IFN-gamma not only promotes proteasomal cleavages that determine the C termini of antigenic peptides, but also can stimulate formation of their N termini by inducing LAP. This enzyme appears to catalyze the trimming of the N terminus of this and presumably other proteasome-derived precursors. Thus, susceptibility to LAP may be an important influence on the generation on immunodominant epitopes.
Four modified cyclic hexapeptides, tenuecyclamides A-D (1-4), were isolated along with the known antibiotic, borophycin (5), from the methanol extract of Nostoc spongiaeforme var. tenue (TAU strain IL-184-6). The planar structure of tenuecyclamides A-D (1-4) was determined by homonuclear and inverse-heteronuclear 2D-NMR techniques as well as by high-resolution mass spectrometry measurements. The absolute configuration of the asymmetric centers was studied by Marfey's method for HPLC. The stereochemistry of the asymmetric centers in tenuecyclamides A and B (1 and 2) could not be fully determined, while that of tenuecyclamides C and D (3 and 4) was unambiguously determined.
The production of volatile odour compounds by freshwater phytoplankton was monitored weekly from November to April (summer period) 1990/91 at two sites: (1) Hay Weir pool on the Murrumbidgee River, NSW and (2) Carcoar Dam, near Blayney, NSW. During this period, the phytoplankton of the Murrumbidgee River was dominated by two species of the diatom Melosira, and the cyanobacterium Anabaena sp. Carcoar Dam was mostly dominated by the cyanobacteria Microcystis aeruginosa and Anabaena sp. The major odour compounds detected were geosmin, β-cyclocitral, β-ionone, geranylacetone, and 6-methylhept-5-en-2-one. Clmparison of multivariate statistical analyses of the volatile odour compound profiles and algal population data provided strong evidence for the hypothesis that the major source of many of these odour compounds was the phytoplankton. Total (intra+extracellular) geosmin concentration was strongly correlated with Anabaena abundance with no significant difference in geosmin production between sites. From the overall average of 10 fg geosmin cell−1 it is possible to predict that taste and odour problems, due to geosmin, may be experienced at Anabaena abundances of > 1,000-2,000 cells ml−1 in temperate Australian waters. β-cyclocitral concentration was correlated with Microcystis abundance at Carcoar Dam (10 fg β-cyclocitral cell−1), but with Anabaena sp. abundance at Hay Weir (2 fg cell−1).
Oscillatoria rubescens and O. redekei were isolated (not free of bacteria) and cultivated. Alterations of trichome-diameter, cell-length, buoyancy and pigmentation in relation to cultivation-conditions were investigated. The growth — C-fixation, increase of dry substance, extinction and cell number — were measured under different cultivation-conditions, too.
Screening of the aqueous extracts of 15 cultured cyanobacterial strains and 4 cyanobacterial waterblooms for antiviral activity against Influenza virus A in the cellular test system Influenza virus A/WSN33/London - MDCK cells resulted in the detection of an antiviral activity in three extracts, prepared of field collected biomass of Oscillatoria tenuis SPH 03 and Microcystis aeruginosa SPH 01 and the cultured cyanobacterial strain Microcystis firma 398. The best antiviral effect without any cytotoxicity against MDCK cells up to a concentration of 1000 μg/ml was shown by the Microcystis extract. The concentration for 50% inhibition of virus replication was 10.2 μg/ml. The antiviral effect was verified in the Allantois on shell system using different subtyps of Influenza virus A and B. The virus replication was inhibited for 90% with only 10-20 μg extract/ml. No cytotoxic effects were observed up to concentrations of 400 μg/ml. Surprisingly all tested strains of influenza virus A did not become resistant against the cyanobacterial extract after continous incubation about several virus passages.
In principle, the isolation and purification of cyanobacteria from saline environments does not differ from that for other groups of cyanobacteria (see this Handbook, Chapter 8 for general discussion and Table 1 in this chapter for specific media for marine and halophilic forms). In this chapter, the cyanobacteria of marine and hypersaline environments will be discussed seChapautely; the physiological properties which distinguish these cyanobacteria from others and the range of taxonomic diversity encountered in saline environments will be indicated.
Cyanobacteria (blue - green algae) are one of the largest group of Gram -negative, photosynthetic prokaryotes, which are morphologically diverse and highly widespread in salt and sweet water and also in terrestrial habitats. They play a significant role as primary producers in many ecosystems. Some species of Cyanobacteria are capable to grow extensively and formate toxic water blooms which can be dangerous for animal and human health. Certain species of them produce a wide variety of bioactive compounds which can have potential biotechnological cosmetical and pharmaceutical applications. Cyanobacteria have recently been identified as one of the most promising group of organisms from which large number of novel, biochemically active natural compounds can be isolated.
The blue green algae are able to synthesize many pharmacologically active secondary products, serving as their chemical weapons. Because of the toxicity of these compounds directed against man and animal as well as their potential role as drugs blue green algae were investigated in the last decade with growing intensity regarding chemistry and the pharmacology of their active agents. The substances isolated on this occasion belong above all to the groups of polyketides, amides, alkaloids, and peptides. Dependent on the screening methods used, the effects of the isolated potential drugs were mainly cytostatic, antibiotic and antimycotic. Besides that cardiotonic action, calcium antagonism, tyrosinase inhibition, acetylcholinesterase inhibition, blockade of Na+ channels and nicotinergic action were observed. Taking into account our recent knowledge in this field, it seems promising to try new screening strategies and to develop new methods of cultivation of blue green algae to make them accessible as a new source of effective drugs.
46 species of 10 families of basidomycetes were screened for trypsin-inhibitor activity. These mushrooms were extracted with water to estimate the inhibitor activity. High inhibitor activity (trypsinhibition higher than 50%) was estimated in 8 species of 5 families.Zusammenfassung46 Arten aus 10 Familien von Basidiomyceten wurden auf ihre Trypsininhibitorwirkung untersucht. Der klare, wäßrige Extrakt wurde zur Bestimmung der Inhibitoraktivität eingesetzt. Eine hohe Inhibitoraktivität wurde in 8 Arten von 5 Familien bestimmt.
The wide range of secondary metabolites from cyanobacteria includes cyclic depsipeptides. They can be filed into several classes. Members of class V, the cyanopeptolins, are proposed in this review to be defined as (a) cyanobacterial 19-membered cyclic depsipeptides cyclized by an ester-linkage of the hydroxyl-group of threonine with the carboxy terminus of the C-terminal amino acid of a proposed linear precursor, (b) an unusual 3-amino-6-hydroxy-2-piperidone unit, and (c) a cis-configurated amide linkage between the amino acids in position 3 and 4. The cyanobacterial depsipeptides known so far, matching with this definition, are the cyanopeptolins A, B, C, and D, the aeruginopeptins 228-A, 228-B, 95-A, and 95-B, microcystilide A, the micropeptins A, B, and 90, compound A90720A, and the sulfate-containing cyanopeptolins S and SS.
The cyanopeptolins and related depsipeptides from cyanobacteria may serve a biochemical and pharmacological tools, because most of them exhibit protease-inhibitory and/or cytotoxic activities. The structure-function relationships of the serine protease inhibitor A90720A and trypsin is known by a cocrystallization study. There are indications for a possible cyanobacterial origin of cyanopeptolin-like compounds found in marine eukaryotes.
The production of volatile odour compounds by freshwater pbytoplankton was monitored weekly from November to April (summer period) 1990/91 at two sites. (1) Hay Weir pool on the Murrumbidgee River, NSW and (2) Carcoar Dam, near Blayney, NSW. During this period, the pbytoplankton of the Mumrmbidgee River was dominated by two species of the diatom Melosira, and the cyanobacterium Anabaena sp. Carcoar Dam was mostly dominated by the cyanobacteria Microcystis aeruginosa and Anabaena sp. The major odour compounds detected were geosmin, β-cyclocitral, β-ionone, geranylacetone, and 6-methylhept-5-en-2-one. Comparison of multivariate statistical analyses of the volatile odour compound profiles and algal population data provided strong evidence for the hypothesis (bat the major source of many of these odour compounds was the pbytoplankton. Total (intra+extracellular) geosmin concentration was strongly correlated with Anabaena abundance with no significant difference in geosmin production between sites. From the overall average of 10 fg geosmin cell−1 it is possible to predict that taste and odour problems, due to geosmin, may be experienced at Anabaena abundances of > 1,000-2,000 cells ml−1 in temperate Australian waters. β cyclocitral concentration was correlated with Microcystis abundance at Carcoar Dam (10 fg β-cyclocitral cell−1), but with Anabaena sp. abundance at Hay Weir (2 fg cell−1).
Lyngbyabellin A (1), a significantly cytotoxic compound with unusual structural features, was isolated from a Guamanian strain of the marine cyanobacterium Lyngbya majuscula. This novel peptolide is structurally related to dolabellin (2) in that both depsipeptides bear a dichlorinated beta-hydroxy acid and two functionalized thiazole carboxylic acid units. Its gross structure has been elucidated by spectral analysis, including 2D NMR techniques. The absolute stereochemistry of 1 was determined by chiral HPLC analysis of hydrolysis products and by characterization of the degradation products methyl 7,7-dichloro-3-hydroxy-2,2-dimethyloctanoate (3) and the corresponding acid 4. The total structure was further supported by molecular modeling studies. The isolation of 1 from L. majuscula once more supports the proposal that many compounds originally isolated from the sea hare Dolabella auricularia are of cyanobacterial origin. Lyngbyabellin A (1) was shown to be a potent disrupter of the cellular microfilament network.
The crude aqueous extract of a field collected strain of Microcystis aeruginosa (Kütz) showed antiviral activity against influenza A virus. The concentration for 50% inhibition of virus replication in MDCK cells was 11 μg dry extract/mL. The virus specific protein synthesis decreased if the extract was present over the whole time of replication. Furthermore protease inhibitory activity was estimated for the crude aqueous extract and subextracts. © 1997 by John Wiley & Sons, Ltd.
In the course of our screening program for bioactive compounds, a novel lipopeptide, nostofungicidine (1), was isolated from the methanolic extract of a fiel-grown terrestrial blue-green alga, Nostoc commune. The structure of nostofungicidine was elucidated by chemical degradation and extensive NMR measurements including DQF-COSY, HOHAHA, HMBC, and ROESY techniques. Nostofungicidine contains a novel β-amino acid, 3-amino-6-hydroxy stearic acid (Ahs) in its structure.
Two cyclic peptides, anabaenopeptins A (1) and B (2), were isolated as a third group of bioactive compounds fromAnabaena flos-aquae NRC 525-17. Their structures were determined by 2D-NMR techniques and Marfey's method combined with LC/MS.
Aeruginosins 102-A and B were isolated from the freshwater cyanobacterium Microcystis aeruginosa (NIES-102). Their structures were elucidated to be 1 and 2 on the basis of 2D NMR data and chemical degradation. These peptides inhibited thrombin potently.
From 1977 to 1979 plankton samples were taken from 6 lakes in the German Democratic Republic (GDR) during water blooms and examined for their toxicity to homothermal animals. Microcystis aeruginosa, Aphanizomenon flos-aquae, Anabaena spiroides, and Oscillatoria redekei were dominant in the samples. With the exception of Oscillatoria redekei the algae tested had toxic effects on mice after intraperitoneal injection. The rate of survival of the test animals was particularly low when the algae were disintegrated by ultrasound or freeze-drying prior to injection, this indicating the endogenic character of the toxins. Water blooms of Microcystis aeruginosa taken from Lake Pehlitzsee (Eberswalde District) showed the highest toxicity with an LD30 as high as 45 and 43.7 mg/kg, respectively. Injection of the lyophilized cells of Aphanizomenon flos-aquae brought about the same symptoms in the test animals as in the case of Microcystis, but the LD30 was 200 mg/kg.
Aeruginosins 98-A and B, trypsin inhibitors, were isolated from the cultured freshwater blue-green alga Microcystis aeruginosa. Their structures were elucidated to be 1 and 2 respectively on the basis of 2D NMR data and chemical degradation. These peptides inhibited trypsin potently with an IC50 of 0.6 μg/ml.
In order to find new sources of antiviral agents with different mechanisms of action, extracts of 49 algae were assayed for antiherpes simplex virus (HSV) and anti-human immunodeficiency virus (HIV) activities. Twenty-five aqueous extracts showed anti-HSV activity, four of which were found to be most potent inhibitors with a selective index more than 1000. Eight samples of the aqueous extracts were identified as having activity against HIV replication. The result suggests that the extracts from algae are a promising source of antiviral agents which may act on different stages in virus replication cycle.
Since 1981 we have cultured and prepared lipophilic and hydrophilic extracts from more than 1500 strains representing some 400 species of blue-green algae. Screening for a wide variety of potentially useful bioactivities, including cytotoxic, multi-drug-resistance reversal, antifungal, and antiviral effects, has led to the discovery and identification of numerous novel bioactive metabolites including peptides, macrolides and glycosides.A systematic evaluation of the chemical and environmental factors that influence the production of secondary metabolites inScytonema ocellatum, which produces tolytoxin (a macrocyclic lactone that depolymerizes actinin vivo to disrupt cell division in eukaryotic organisms), has shown that cyanophytes can be manipulated in culture to improve growth and product yields.
Cyanobacteria produce a large number of compounds with varying bioactivities. Prominent among these are toxins: hepatotoxins such as microcystins and nodularins and neurotoxins such as anatoxins and saxitoxins. Cytotoxicity to tumor cells has been demonstrated for other cyanobacterial products, including 9-deazaadenosine, dolastatin 13 and analogs. A number of compounds in cyanobacteria are inhibitors of proteases — micropeptins, cyanopeptolins, oscillapeptin, microviridin, aeruginosins- and other enzymes, while still other compounds have no recognized biological activities. In general cyclic peptides and depsipeptides are the most common structural types, but a wide variety of other types are also found: linear peptides, guanidines, phosphonates, purines and macrolides. The close similarity or identity in structures between cyanobacterial products and compounds isolated from sponges, tunicates and other marine invertebrates suggests the latter compounds may be derived from dietary or symbiotic blue-green algae.
Microcystis andNodularia species produce cyclic hepta- and pentapeptides, microcystins and nodularin, respectively, both containing the same unusual C20 amino acid, abbreviated Adda. Biosynthesis of nodularin fromNodularia and especially of Adda employs a pathway similar to that employed byMicrocystis for producting microcystins. Nearly 30 new microcystins have been isolated in our laboratory from cyanobacteria species and their structures assigned, largely employing tandem FAB mass spectrometry (FABMS/CID/MS). Acyclic peptides, some of them presumed precursors of nodularin and microcystins, have now been isolated and characterized. The numerous analogs identified or synthesized allow the identification of important parameters in a structure-activity relationship study.
Methanol extracts fromChlorococcum strain HS-101 andDunaliella primolecta strongly inhibited the growth of a strain of methicillin-resistantStaphylococcus aureus (MRSA), which is causing serious problems in Japanese hospitals. So that the anti-MRSA substance(s) could be purified and identified, the growth medium was improved for antibiotic production. When the two strains were cultured in their improved media, antibiotic production byChlorococcum strain HS-101 was 1.8-fold that in the standard BG-11 medium, and production byD. primolecta was 2.3-fold. The activity pattern of fractions eluted by silica-gel or gel-permeation chromatography suggested that both strains produced two antibiotic substances. Identification of the purified substances by NMR and GC-MS showed that one of the active substances in both strains was-linolenic acid. Ten fatty acids from other sources were tested, and it was found that unsaturated fatty acids had antibiotic activity against MRSA, with the highest activity that of -linolenic acid.
The T lymphocyte-mediated induction of angiotensin-converting enzyme (ACE) in cultured autologous peripheral blood monocytes has been proposed as a model system for the investigation of the in vivo induction of ACE in the monocyte-derived granuloma epithelioid cells of some granulomatous diseases such as sarcoidosis. The studies described here were designed to evaluate the specificity of the model system by comparing the parameters for induction of ACE with those for the induction of another monocyte metallo-ecto-peptidase, leucine aminopeptidase (LAP). The concentration of LAP in freshly isolated monocytes was 0.09 mU/10(6) monocytes (s.e.m. 0.04) and increased to a maximal value of 0.19 mU/10(6) monocytes (s.e.m. 0.32) after 3 days when monocytes were cultured alone. ACE was not detectable in freshly isolated monocytes. However, after 6 days of culture, monocytes contained 0.22 mU ACE/10(6) monocytes (s.e.m. 0.04). Comparison of the levels of ACE and LAP induced during culture of monocytes alone indicated that the induction of these two enzymes were correlated. The induction of both enzymes was further enhanced by the presence of T lymphocytes in a dose-dependent manner. At 4 x 10(6) T lymphocytes per culture, ACE levels increased to 1.81 mU/10(6) monocytes (s.e.m. 0.24) and LAP levels to 1.03 mU/10(6) monocytes (s.e.m. 0.35). The enhancement of ACE activity required autologous lymphocytes, while heterologous T lymphocytes were equally effective in inducing LAP. Comparison of the levels of ACE and LAP induced during coculture of autologous T lymphocytes and monocytes from 21 independent donors, demonstrated no correlation between the induction of ACE and LAP. These data indicate that, although T lymphocytes also enhance the induction of LAP, the underlying mechanism must differ from that of ACE induction.
An autolytic substance in an axenic cyanobacterium, Phormidium tenue, was identified as a mixture of fatty acids, by use of cultured cells in the laboratory. Among them, linoleic acid and linolenic acid were potent growth inhibitors.
The effect of interferon-alpha (Wellferon) on human monocyte to macrophage maturation in vitro has been investigated. Cell volume and three markers, acid phosphatase, leucine aminopeptidase, and phagocytosis, which increase with maturation, have been studied employing recently developed flow cytofluorometric techniques. The increase in cell volume and in the expression of all three markers was inhibited in a dose-dependent manner in monocyte cultures given 50-300 U/ml of interferon within 2 hr of culture initiation. An initial dose of 300 U/ml of interferon, removed from the cultures after 24 hr, was as effective in inhibiting the development of each of the markers as three 100 U pulses on three consecutive days, and as effective as 300 U interferon left in throughout the culture period. Histogram analysis of marker expression indicated that all monocytes, and not a subpopulation, were affected by the interferon. Cytotoxic activity of freshly isolated monocytes rapidly decayed when the cells were cultured under standard maturation conditions. The addition of interferon to the cultures prevented the loss of this activity while also preventing the development of more mature cells. It appears that maintenance of the cytotoxic state is one influence of interferons; however, it may be that these cells have also been directed toward alternate pathways of macrophage differentiation.
An extract of the cyanobacterium P. tenue showed a significant inhibitory effect on its own growth. Bioassay-directed fractionation has led to the identification of the auto-growth inhibitory substance as a mixture of fatty acids. Unsaturated fatty acids such as linoleic and linolenic acids appear to be predominantly responsible for the auto-growth inhibitory effect.
A method for screening of antiviral compounds against adenoviruses was established. Test compounds were diluted and plated in chamber slides for tissue culture. Drug-treated, virus-infected cultures were stained with fluorescein isothiocyanate conjugated rabbit antibodies against adenovirus hexon type 2 and fluorescent cells were counted by microscopy. This assay is more sensitive than the colorimetric method and requires smaller volumes of compounds when compared with the standard method using plaque assay.
Bioactivity-directed fractionation of a hot H2O extract from a blue-green alga Spirulina platensis led to the isolation of a novel sulfated polysaccharide named calcium spirulan (Ca-SP) as an antiviral principle. This polysaccharide was composed of rhamnose, ribose, mannose, fructose, galactose, xylose, glucose, glucuronic acid, galacturonic acid, sulfate, and calcium. Ca-SP was found to inhibit the replication of several enveloped viruses, including Herpes simplex virus type 1, human cytomegalovirus, measles virus, mumps virus, influenza A virus, and HIV-1. It was revealed that Ca-SP selectively inhibited the penetration of virus into host cells. Retention of molecular conformation by chelation of calcium ion with sulfate groups was suggested to be indispensable to its antiviral effect.
Toxic cyanobacterial blooms are a threat because of secondary metabolite production. We used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to identify intact microorganisms. Microgram quantities of prepared cells, including solvent (acetonitrile and ethanol) and alpha-cyano-4-hydroxycinnamic acid matrix, display spectra showing predominantly the secondary metabolites including known microcystins, micropeptin, and anabaenopeptolin. A new cyclic anabaenopeptolin has been identified using the Post-Source-Decay mode. Strains of various origins can easily be typed according to their cyclic peptide production, and toxic and nontoxic algal blooms can be differentiated within minutes.
A new solid tumor selective cytotoxic analogue of dolastatin 10 (1) has been isolated from the marine cyanobacterium Symploca hydnoides, collected near Guam. This metabolite has been assigned the trivial name symplostatin 1 (2). This discovery supports the proposal that many compounds isolated from the seahare Dolabella auricularia, the original source of the dolastatins, are of dietary origin.
Bioassay guided fractionation of the lipophilic extract of the marine cyanobacterium Phormidium ectocarpi yielded a new natural product hierridin B and the previously described compound 2,4-dimethoxy-6-heptadecyl-phenol. Both structures were secured by extensive spectroscopic analysis (1D and 2D NMR, MS, GC-MS, IR). The isolate (mixture) showed antiplasmodial activity towards Plasmodium falciparum.
A novel extracellular metabolite with an unprecedented diterpenoid skeleton, 8-[(5-carboxy-2-hydroxy)benzyl]-2-hydroxy-1,1,4a,7, 8-pentamethyl-1,2,3,4,4a,6,7,8,8a,9,10,10a-dodecahydrophenanthrene , has been isolated from the culture medium of the terrestrial cyanobacterium Nostoc commune Vaucher (EAWAG 122b) by means of bioguided isolation. The molecule was designated as noscomin. The structure was determined by spectroscopic methods, mainly NMR and mass spectrometry. Noscomin exhibited antibacterial activity against Bacillus cereus, Staphylococcus epidermidis, and Escherichia coli.
An analogue of dolastatin 13 (2) has been isolated from a marine cyanobacterium, Symploca hydnoides, collected near Guam. This new cyclic depsipeptide contains a L-methionine sulfoxide residue; however, the sulfoxide exists as both R- and S-forms, resulting in the doubling of several signals in the 1H and 13C NMR spectra. Structure elucidation required extensive application of 2-D NMR techniques such as COSY, HMQC, HMBC, and ROESY. The trivial name symplostatin 2 (1) has been assigned to the new metabolite and its isolation from S. hydnoides further supports the proposal that many compounds originally isolated from the sea hare Dolabella auricularia are most probably of cyanobacterial origin.