Figures 28-35 - uploaded by Maria Teresa de P. Azevedo
Content may be subject to copyright.
Chroococcales species from São Paulo State. 28-29. Microcystis protocystis. 28. General aspect of colony. 29. Detail of cells with individual envelope. 30. Different Microcystis species forming bloom: M. protocystis (A), M. panniformis (B), M. aeruginosa (C). 31. M. panniformis. 32. M. wesenbergii. 33. Coelomoron cf. tropicale: atypical colonies showing cells not densely aggregated. 34-35. Radiocystis fernandoi. 34. General aspect of colonies. 35. Colony showing the radial cells organization. Bars = 10 µm (29, 33), 50 µm (28, 32, 34), 20 µm (30, 35), 100 µm (31).
Source publication
Planktic Cyanobacteria from São Paulo State, Brazil: Chroococcales). The biodiversity studies of planktic cyanobacteria started in 1997 with intensive collecting in different water bodies of São Paulo State. Due to the problems brougth by eutrophication and cyanobacterial blooms, the samplings were concentrated in reservoirs of Alto Tietê region th...
Similar publications
Increased eutrophication in the recent years has resulted in considerable research focus on identification of methods for preventing cyanobacterial blooms that are rapid and efficient. The objectives of this study were to investigate the effects of dihydroartemisinin and artemether on the growth of Microcystis aeruginosa and to elucidate its mode o...
In recent years, algae bloom phenomenon outbreaks frequently in large-scale water bodies during summer. At present, mechanical method is used to collect cyanobacteria and reduce volume. However, the characteristics of algae, namely high viscosity, small particle size and high moisture content, lead to poor efficiency of dehydration. In order to imp...
The physiochemical and planktonic community responses of the water column to the introduction of silver and bighead carp at a biomass of 50 g m−3 were studied in enclosures in the hypereutrophic Meiliang Bay of Lake Taihu over a 54-day period. Groups of silver carp and bighead carp stocked at weight ratios of 1:0 (G1), 1:1(G2) and 1:2 (G3) as well...
The study of the composition of Planktonic blue-green algae was under taken for the period
of eight months (February–September, 2007). Assessment of physicochemical characteristics of the river
was also attempted to find out the state of the water quality of the river. Twenty four species of bluegreen
algae were observed belonging to two orders nam...
The field monitoring data was used to analyze the distribution and its influencing factors of bloom-forming cyanobacteria and explore the source of bloom-forming cyanobacteria in Poyang Lake. It resulted that diatoms was dominant in Poyang Lake, cyanobacteria was sub-dominant, and there is a rising trend of the proportion of cyanobacteria in the co...
Citations
... Approximately 20 individuals from each taxon were evaluated morphologically and morphometrically. Their identification was based on relevant classical literature (Komárek and Fott, 1983;Sant'Anna, 1984;Komárek and De Paiva Azevedo, 2000;Sant'Anna et al., 2004;Godinho et al., 2010). ...
The present work aimed to investigate the effects of adding CO 2 to the treatment carried out by native microalgae in a raceway pond with high load sewage to remove E. coli and total coliforms, as well as to evaluate the influence of shading on the treatment system operated on a pilot scale, outdoors under actual conditions in real time analysis. There were significant correlations between total coliforms and E. coli removals with abiotic parameters such as pH and dissolved oxygen. From the results, it was observed that in the experiments without shading the removal of total coliforms and E. coli were better. It can be concluded that they were factors acting synergistically for the success of the pathogenic removal of coliforms and this may be the occurrence of endogenous photo-oxidation and oxidative stress in microbial cell leads to DNA damage and cell death due inactivate the metabolic growth of the cells. Further, the final effluent generated by the pond cannot be used for direct reuse, a post-treatment is necessary to fit within the established limits so as to increase the possibilities of its reuse.
... For phytoplankton analysis, untreated water samples were Lugol-fixed for subsequent identification and quantification in sedimentation chambers using an inverted microscope (Olympus CK2) at 400× magnification following the Utermöhl (1958) [34] method. Phytoplankton taxa were identified according to specialized literature [35][36][37][38][39][40]. A counting limit was established through the species-rarefying curve until reaching 100 individuals (cell, filament, colony, and coenobium) of the most common species. ...
Freshwater reservoirs constitute an important source of drinking water, but eutrophication and higher temperatures increase the risk of more frequent blooms of cyanobacteria, including species that produce toxins. To improve the prediction of cyanotoxin episodes, we studied the annual occurrence of potential microcystin (MC) and saxitoxin (STX)-producing cyanobacteria in the Lobo reservoir, São Paulo State, Brazil. Relationships among environmental variables, cyanobacterial biomass, numbers of the mcyE and sxtA genotypes (genes encoding production of MC and STX, respectively), and concentrations of MC and STX were determined to address variables applicable for monitoring and predicting the dynamics of cyanobacteria and cyanotoxins in the reservoir. Microscopy confirmed the presence of potentially toxin-producing cyanobacteria at all sampling times, and qPCR detection showed the occurrence of both mcyE and sxtA in most samples. Concentrations of MC and STX were generally low (MC 0–1.54 µg L−1; STX 0.03–0.21 µg L−1). The highest MC level exceeded the recommended limit for human intake of 1 µg L−1. The abundance of the mcyE and sxtA genes, as well as the toxin concentrations, were positively correlated with the biomass of Phormidium and Raphidiopsis. Among environmental variables, the abundance of potential toxic cyanobacteria was mainly affected by P limitation (high TN:TP ratios). Our data show that detection of the mcyE and sxtA genotypes serves as a useful and reliable predictor of toxin episodes but might be combined with chemical toxin detection to form an environmental toolbox for cyanotoxin monitoring.
... Silva and Pienaar (1999) surveyed entire South Africa and recorded 40 taxa consisting of 18 genera from 6 families of this order. Planktic Cyanobacteria of SauPaulo, Brazil was investigated and 26 taxa including natural as well as cultural samples of Chroococcales were recorded by Sant'Anna (2004). Extensive studies from north western Australia revealed 54 species having dominant taxa like, Aphanocapsa, Cyanodictyon, Myxobaktron, Merismopedia and Microcystis (Mc Gregor, 2007). ...
Unicellular Cyanobacteria from aquatic as well as aerial and subaerial habitats of West Bengal were explored in the current survey. A total of 7 taxa namely Chroococcidiopsis thermalis, Snowella fennica, Snowella lacustris, Chlorogloea tuberculosa, Chlorogloea novacekii, Hydrococcus cesatii and Aphanocapsa hyalina were found new to India.
... Las microfotografías fueron editadas para hacer homogéneo el brillo y el contraste con Adobe Photoshop 23.31. Para la identificación de las especies se utilizó la siguiente bibliografía: Bicudo y Menezes (2006), Bourrelly (1970), Ciugulea y Triemer (2010), Comas (1996Comas ( , 2009), Croasdale et al. (1983), González e Inostrosa (2017), González-Guerrero (1941), Huber-Pestalozzi (1955), John et al. (2002), Komárek (2013), Komárek y Anagnostidis (1999, 2005, Komárek y Fott (1983), Krammer y Lange-Bertalot (1986, 1988, 1991a, b), Lange-Bertalot (2001), Parra et al. (1982aParra et al. ( , b, 1983, Rivera et al. (1982), Round et al. (2000), Sant'Anna (1984), Sant'Anna et al. (2004, 2012 y Tomas (1997). ...
En Tabasco se han reconocido 699 taxones algales dulceacuícolas, cifra que consideramos baja, dado que resguarda el mayor número de cuerpos de agua dulce del país y alberga la Reserva de la Biosfera Pantanos de Centla (RBPC), el humedal tropical más extenso, que por su compleja hidrología y biodiversidad es uno de los sitios más importantes de su tipo en Mesoamérica. El objetivo central de este estudio consistió en registrar y documentar las especies fitoplanctónicas de las lagunas El Viento y San Pedrito, localizadas al interior de la RBPC, durante 2 períodos, lluvias de norte (noviembre 2016) y secas (febrero 2017). Se documentaron 67 especies, 4 de ellas se registran para México por primera vez y 18 para la entidad. El 67% se presentan en sistemas acuáticos eutrofizados, con una forma de vida típicamente planctónica (73%). La cantidad y variedad de cuerpos acuáticos en la entidad, la ubicación de la RBPC y la influencia de la región hidrológica Grijalva-Usumacinta, hacen notable la gran diversidad de algas y de procariotas fotoautotróficos (Cyanoprokaryota).
... According to Komárek and Anagnostidis (1998), this species is cosmopolitan. In Brazil, species of the genus Aphanocapsa were found as producers of microcystin [32]. ...
... Although some genera related to the production of microcystins were identified at the sampling points, the positive results for the presence of the specific gene encoding microcystin (Table 3), specially at the points P3 and P4, may be related to the genus Aphanocapsa, which was observed in greater quantity at these points (Table 1) [26,32,40]. ...
The Joanes I Reservoir is responsible for 40% of the drinking water supply of the Metropolitan Region of Salvador, Bahia, Brazil. For water sources such as this, there is concern regarding the proliferation of potentially toxin-producing cyanobacteria, which can cause environmental and public health impacts. To evaluate the presence of cyanobacteria and their cyanotoxins in the water of this reservoir, the cyanobacteria were identified by microscopy; the presence of the genes of the cyanotoxin-producing cyanobacteria was detected by molecular methods (polymerase chain reaction (PCR)/sequencing); and the presence of toxins was determined by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The water samples were collected at four sampling points in the Joanes I Reservoir in a monitoring campaign conducted during the occurrence of phytoplankton blooms, and the water quality parameters were also analysed. Ten cyanobacteria species/genera were identified at the monitoring sites, including five potentially cyanotoxin-producing species, such as Cylindrospermopsis raciborskii, Cylindrospermopsis cf. acuminato-crispa, Aphanocapsa sp., Phormidium sp., and Pseudanabaena sp. A positive result for the presence of the cylindrospermopsin toxin was confirmed at two sampling points by LC-MS/MS, which indicated that the populations are actively producing toxins. The analysis of the PCR products using the HEPF/HEPR primer pair for the detection of the microcystin biosynthesis gene mcyE was positive for the analysed samples. The results of this study point to the worrisome condition of this reservoir, from which water is collected for public supply, and indicate the importance of the joint use of different methods for the analysis of cyanobacteria and their toxins in reservoir monitoring.
... Quantitative analysis was performed with an inverted microscope (Zeizz Axiovert 40 C) at 400× magnification, using a sedimentation chamber, as described by Utermöhl (1958). Biomass (mg L − 1 ) was determined by multiplying the density (ind mL − 1 ; Ross, 1979) by the cell volume (mm 3 ; Hillebrand et al., 1999), assuming the fresh unit weight expressed as a mass of 1 mm 3 L − 1 = 1 mg L − 1 (Wetzel and Likens, 2000). ...
... Studies have shown representatives of this morphofunctional group, such as the recognized potentially toxic cyanobacterium Microcystis aeruginosa, being resistant to sedimentation and still forming suspended aggregates at the top of the tubes with the addition of coagulants, such as chitosan Miranda et al., 2017). In our study, Microcystis aeruginosa did not occur and the only representative of MBFG VII was the cyanobacterium Aphanocapsa delicatissima, which forms small and weakly aggregated colonies with hyaline mucilaginous sheath (Sant'Anna et al., 2004), which would justify the results observed. It is worth noting that, in addition to these characteristics, unlike M. aeruginosa, Aphanocapsa delicatissima does not have aerotopes in cells (Padisák et al., 2003;Naselli-Flores et al., 2007), a characteristic that reinforces resistance to settling. ...
The Floc and Sink technique promotes, through the application of coagulants and clays, the removal of phosphorus and algal biomass from the water column by flocculation and sedimentation. Although it is a promising technique for mitigating harmful cyanobacterial blooms, little is known about the impacts on other phytoplankton species as well as it is not known how species with mechanisms of resistance to sedimentation respond to the application of these products. In this study, a laboratory experiment was carried out with water from a eutrophic reservoir to assess the impact of applying aluminum-based coagulants, aluminum sulfate and polyaluminium chloride, and chitosan, alone and combined with lanthanum modified bentonite and natural bentonite on the phytoplankton community, in a functional approach based on morphology (Morphology-Based Functional Groups – MBFG, Kruk et al., 2010 and Reynolds et al., 2014), with an emphasis on the characteristics that provide resistance to sedimentation. We tested two hypotheses: phytoplankton species with adaptive mechanisms that provide buoyancy to cells are more resistant to the removal from the water column by coagulants and clays; and coagulants based on metals and modified clays are more efficient in sedimentation of microalgal cells compared to natural products, regardless of the presence of an adaptive mechanism of resistance to sedimentation. Our results showed that aluminum sulfate and polyaluminium chloride alone or combined with lanthanum modified bentonite and natural bentonite effectively sedimented the cells, regardless of the presence of buoyancy mechanisms. In contrast, the natural coagulant chitosan alone or combined with lanthanum modified bentonite and natural bentonite removed only those species that were small-celled or small colonial without specialized structures or with the presence of spines, arms and siliceous exoskeleton. In the case of species with aerotopes and flagella, the removal was not effective and still caused an increase in algal biomass due to the formation of suspended cell aggregates on the surface of the water column of the experimental units. Therefore, we concluded that the Floc and Sink technique has an impact on the phytoplankton community because it removes from the water column species that are not the target of coagulants and clays, but that are considered important sources of energy in freshwater trophic webs. This result differs according to the type of product used as well as it is related to the morphological adaptations that favor the buoyancy of cells in the water column. Species with aerotopes and flagella are more resistant to sedimentation and may make the use of products applied in the Floc and Sink technique unfeasible. Nevertheless, these results represent only an immediate effect of the technique on the phytoplankton community, thus requiring a longer time scale evaluation to determine the algae that can effectively recover water column. Therefore, we also emphasize that algae of nutritional value can recover over time and make the long-term application of the technique acceptable.
... For phytoplankton analysis, samples were Lugol-fixed for subsequent identification and quantification in sedimentation chambers using classical phytoplankton counting method in inverted microscope (Zeiss Axiovert 25) at 400-fold magnification by Utermöhl technique (Utermöhl, 1958). Specialized literature was used for the taxonomic classification of phytoplankton organisms Anagnostidis, 1998, 2005;Wehr and Sheath, 2003;Sant'Anna et al., 2004;Komárek, 2013;Bicudo and Menezes, 2017). Photographic documentation for presence of selected species are shown in Fig. S3. ...
Diversity of phytoplankton in three eutrophic and two mesotrophic lakes in Denmark was determined by microscopic and HPLC pigment analyses to identify and quantify potential saxitoxin (STX) producing cyanobacteria. Potential dominant STX-producers were identified to the filamentous genera Dolichospermum, Cuspidothrix, Phormidium and Planktolyngbya. Presence of STX production was documented by extraction of five intracellular STXs that included (in declining concentration in the cyanobacteria) dc-neo-STX, neo-STX, dc-STX, STX and GTX. Total concentrations of the five STXs varied from 9 to 142 fg per potential STX producer, corresponding to 87 to 985 ng L⁻¹ in the lakes. For molecular detection of the STX-producers, a quantitative PCR method was developed by design of a new robust primer set with broad coverage to target the sxtA gene that is common to all STX-producing cyanobacteria. After validation, copy numbers of the sxtA gene were determined to vary from about 10⁴ (mesotrophic lakes) to 10⁸ per mL (the most eutrophic lake). A moderate but significant correlation was observed between abundance of the sxtA copies and concentrations of the five intracellular STXs. The qPCR assay was found to be a rapid and robust procedure for quantification of STX producers. Saxitoxin and its analogs appeared not to cause health concerns in the lakes, but commercial fishing for pike perch in the most eutrophic lake should be monitored to test for food web accumulation of STXs.
... The phytoplankton classification follows specific literature (Komárek & Anagnostidis, 1998;Sant'Anna et al., 2004;Komárek & Anagnostidis, 2005;Hoffmann et al., 2005;Metzeltin & Lange-Bertalot, 2007;Godinho et al., 2010;Rodrigues et al., 2010;Rosini et al., 2012;Rosini et al., 2013b;Rosini et al., 2013a;Cavalcante et al., 2013;Almanza et al., 2016;Campanelli et al., 2017). Statistical analysis: Shapiro-Wilks test and Levene's test were used to evaluate the normality of distributions and the equality of the variances for all abiotic and biotic data. ...
In phytoplankton communities, dissimilarities in the species composition and abundance can be correlated with environmental variability at different spatial and temporal scales. This environmental variability can ascertain periodic replacements in phytoplankton assemblages, favoring, in some cases, the growth and dominance of specific algae groups. In this study, the occurrence of spatial/temporal dissimilarities (variation in the density of different taxonomic groups) in the phytoplankton community and their correlations with the environmental variability were studied in an artificial reservoir located in southern Brazil. Seasonal alternation of dominant groups was observed, with dominance of potential harmful cyanobacteria (Aphanizomenon spp. and Dolichospermum spp.) in summer, alien dinoflagellates (Ceratium spp.) in autumn/winter and chlorophytes in spring. The variability of the environmental conditions and resources explained a significant portion of the dissimilarity observed in the phytoplankton community among seasons. In the BioEnv analysis, water temperature explained 53% of the phytoplankton dissimilarities. In the same way, the results of RDA approach pointed to water temperature, pH, soluble solids and nutrient availability as the environmental variables that best explained variability in phytoplankton's densities. These results contribute to understanding the influence of the environmental variability on the phytoplankton structure modulation in subtropical freshwater ecosystems. Furthermore, they warn about the need to consider climate variability (e.g. extreme drought and rain events) on management of water quality and control of harmful and alien algal blooms, especially in disturbed ecosystems. Resumo: Processos climáticos e hidrológicos explicam a dissimilaridade temporal na comunidade fitoplanctônica e favorecem a dominância sazonal de algas nocivas e exóticas em um reservatório subtropical. Nas comunidades fitoplanctônicas, dissimilaridades na composição e abundância das espécies podem estar correlacionadas com a variabilidade ambiental em diferentes escalas espaciais e temporais. Essa variabilidade ambiental pode determinar substituições periódicas nas assembleias fitoplanctônicas, favorecendo, em alguns casos, o crescimento e a dominância de grupos específicos de algas. Neste estudo, a ocorrência de dissimilaridades (variações na densidade dos diferentes grupos taxonômicos) espaciais e Pan-American Journal of Aquatic Sciences (2020), 15(4): 225-243 226 J. ALVES ET AL. temporais na comunidade fitoplanctônica e suas correlações com a variabilidade ambiental foram estudadas em um reservatório artificial localizado no sul do Brasil. Foram observadas alternâncias sazonais dos grupos dominantes, com predominância de cianobactérias potencialmente nocivas (Aphanizomenon spp. e Dolichospermum spp.) no Verão, dinoflagelados exóticos (Ceratium spp.) no Outono/Inverno e algas verdes na Primavera. Na análise BioEnv, a temperatura da água explicou 53% da dissimilaridade do fitoplâncton. Da mesma forma, os resultados da RDA apontaram temperatura da água, pH, sólidos solúveis e disponibilidade de nutrientes como as variáveis ambientais que melhor explicaram a variabilidade nas densidades do fitoplâncton. Esses resultados contribuem para o entendimento da influência da variabilidade ambiental na estruturação do fitoplâncton em ecossistemas subtropicais de água doce. Além disso, eles alertam para a necessidade de considerar as mudanças climáticas (por exemplo, eventos de seca e chuva extremos) na gestão da qualidade da água e no controle da proliferação de algas nocivas e exóticas, especialmente em ecossistemas perturbados. Palavras-chave: Biodiversidade de água doce, Estrutura das comunidades aquáticas, Sucessão sazonal do fitoplâncton, Invasões biológicas, Reservatórios subtropicais.
... According to Anagnostidis (1998) andSant'anna et al. (2004), the order Chroococcales is comprised of all unicellular or colonial cyanobacteria, which do not form true filaments with direct physiological interference between cells. Microcystis aeruginosa, a member of the order Chroococcales, is one of the dominant bloomforming cyanobacterial species in freshwater environments. ...
Cyanobacteria are known to produce a wide variety of bioactive, toxic secondary metabolites generally described as hepatotoxins, neurotoxins, cytotoxins, or dermatoxins. In Brazil, the regular monitoring of cyanobacterial toxins has intensified after the death of 65 patients in a hemodialysis clinic in Caruaru in the state of Pernambuco due to microcystin exposure. The primary objective of this study was to use multivariate statistics that incorporated environmental parameters (both biotic and abiotic) to forecast blooms of cyanobacteria and their toxic secondary metabolites in 20 drinking water reservoirs managed by the Water Treatment Company of Ceará (CAGECE) in the semi-arid region of Ceará, Brazil. Across four years (January 2013 to January 2017), 114 different phytoplankton taxa were identified, including 24 cyanobacterial taxa. In general, Ceará reservoirs were dominated by cyanobacteria due to eutrophication but also because of the dry and warm climate found throughout the region. Interestingly, specific cyanobacterial taxa were influenced by different biotic and abiotic factors. For example, nitrogen-to-phosphorus (N:P) and evaporation were positively related to saxitoxin-producing taxa, especially Raphidiopsis raciborskii, while temperature, electrical conductivity, total phosphorus, and transparency (measured as Secchi depth) were positively associated with microcystin-producing taxa, such as Microcystis aeruginosa. Climate forecasts predict higher evaporation and temperatures in the semi-arid Ceará region, which will likely magnify droughts and water scarcity as well as promote toxic cyanobacterial blooms in reservoirs in the future. Therefore, understanding the factors associated with algal blooms dominated by specific taxa is paramount for water resource management.
... According to Anagnostidis (1998) andSant'anna et al. (2004), the order Chroococcales is comprised of all unicellular or colonial cyanobacteria, which do not form true filaments with direct physiological interference between cells. Microcystis aeruginosa, a member of the order Chroococcales, is one of the dominant bloomforming cyanobacterial species in freshwater environments. ...
Cyanobacteria are known to produce a wide variety of bioactive, toxic secondary metabolites generally de-scribed as hepatotoxins, neurotoxins, cytotoxins, or dermatoxins. In Brazil, the regular monitoring of cyano-bacterialtoxinshasintensifiedafterthedeathof65patientsinahemodialysisclinicinCaruaruinthestateofPernambucoduetomicrocystinexposure.Theprimaryobjectiveofthisstudywastousemultivariatestatisticsthatincorporatedenvironmentalparameters(bothbioticandabiotic)toforecastbloomsofcyanobacteriaandtheirtoxicsecondarymetabolitesin20drinkingwaterreservoirsmanagedbytheWaterTreatmentCompanyofCeará(CAGECE)inthesemi-aridregionofCeará,Brazil.Acrossfouryears(January2013toJanuary2017),114differentphytoplanktontaxawereidentified,including24cyanobacterialtaxa.Ingeneral,Cearáreservoirsweredominated by cyanobacteria due to eutrophication but also because of the dry and warm climate foundthroughouttheregion.Interestingly,specificcyanobacterialtaxawereinfluencedbydifferentbioticandabioticfactors. For example, nitrogen-to-phosphorus (N:P) and evaporation were positively related to saxitoxin-pro-ducingtaxa,especiallyRaphidiopsisraciborskii,whiletemperature,electricalconductivity,totalphosphorus,andtransparency(measured as Secchidepth)were positivelyassociatedwithmicrocystin-producingtaxa, such asMicrocystis aeruginosa. Climate forecasts predict higher evaporation and temperatures in the semi-arid Cearáregion,whichwilllikelymagnifydroughtsandwaterscarcityaswellaspromotetoxiccyanobacterialbloomsinreservoirsinthefuture.Therefore,understandingthefactorsassociatedwithalgalbloomsdominatedbyspecifictaxaisparamountforwaterresourcemanagement
