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... The morphological characteristics of bacterial cells or colonies offer valuable insights into their overall properties and shape. When combined with biochemical tests and microscopic examination, these characteristics aid in the identification and classification of LAB isolates, serving diverse applications across industries, including pharmaceuticals and food [32]. ...
This study aims to investigate the probiotic properties of various isolated strains of Lactiplantibacillus plantarum. Specifically, the focus is on examining the expression of the glutamic acid decarboxylase (GAD) gene and its role in the production of gamma-aminobutyric acid (GABA), a promising postbiotic metabolite. The investigation includes comprehensive analyses of morphology, genetics, resilience against bile, NaCl, and simulated pancreatin juice (SPJ), carbohydrate fermentation patterns, antibacterial activity, susceptibility to antibiotics, and the presence of β-D-galactosidase and GAD enzymes. Six L. plantarum strains exhibited remarkable resilience against bile, NaCl, and SPJ, as well as susceptibility to antibiotics and antagonistic behavior against pathogens. These strains also showed the presence of β-D-galactosidase. Additionally, five L. plantarum strains were found to harbor the gad gene. Further biochemical analysis of four specific L. plantarum strains revealed promising profiles consisting of antibiotics, vitamins, hormones, and a diverse array of metabolites with potential immunotherapeutic properties. This study highlights the substantial potential of Lactiplantibacillus plantarum in generating beneficial postbiotic metabolites. The identified strains offer exciting avenues for further exploration, with potential applications in functional foods and pharmaceuticals. This research opens up possibilities for harnessing the probiotic and postbiotic potential of L. plantarum to develop novel products with health-promoting properties.
... In general, selecting materials compatible with mycelium growth, such as acrylics, polypropylene, silicone, or other materials that withstand the sterilization process and provide a smooth surface for mycelium colonization, is essential [22,154]. Opting for materials that are easily disinfected, resistant to disinfectant solutions (70-75% ethanol, sodium hypochlorite, hydrogen peroxide, etc.), and capable of withstanding high temperatures can streamline production, save time, and reduce costs [155]. This section introduces synthetic materials like high-density polyethylene, polypropylene, and acrylic plastic [22,33]. ...
Mycelium-based green composites (MBCs) represent an eco-friendly material innovation with vast potential across diverse applications. This paper provides a thorough review of the factors influencing the production and properties of MBCs, with a particular focus on interdisciplinary collaboration and long-term sustainability goals. It delves into critical aspects such as fungal species selection, substrate type selection, substrate preparation, optimal conditions, dehydrating methods, post-processing techniques, mold design, sterilization processes, cost comparison, key recommendations , and other necessary factors. Regarding fungal species selection, the paper highlights the significance of considering factors like mycelium species, decay type, hyphal network systems, growth rate, and bonding properties in ensuring the safety and suitability of MBCs fabrication. Substrate type selection is discussed, emphasizing the importance of chemical characteristics such as cellulose, hemicellulose, lignin content, pH, organic carbon, total nitrogen, and the C: N ratio in determining mycelium growth and MBC properties. Substrate preparation methods, optimal growth conditions, and post-processing techniques are thoroughly examined, along with their impacts on MBCs quality and performance. Moreover, the paper discusses the importance of designing molds and implementing effective sterilization processes to ensure clean environments for mycelium growth. It also evaluates the costs associated with MBCs production compared to traditional materials , highlighting potential cost savings and economic advantages. Additionally, the paper provides key recommendations and precautions for improving MBC properties, including addressing fungal strain degeneration, encouraging research collaboration, establishing biosecurity protocols, ensuring regulatory compliance, optimizing storage conditions, implementing waste management practices, conducting life cycle assessments, and suggesting parameters for desirable MBC properties. Overall, this review offers valuable insights into the complex interplay of factors influencing MBCs production and provides guidance for optimizing processes to achieve sustainable, high-quality composites for diverse applications.
... Before use, the strains were thawed and cultured in Brain Heart Infusion broth (B.H.I., Difco, Kansas City, MO, U.S.A.) for 24 h at 37 • C in aerobic conditions (Giardino et al., 2019b). Individual and mixed strains of both microorganisms were smeared on microscope slides following a previously described procedure (Petersen and Mclaughlin, 2016) and then stained by the PAS method. Additional glass slides were smeared with Treponema denticola (T. ...
The bacterial cell wall mainly consists of glycoproteins and polysaccharides, which could be detected in dental tissue with specific stain protocols. The present study aimed to investigate
bacteria stainability in dental histological samples of human teeth by a histochemical method. Eight extracted teeth, because severely decayed, were decalcified, dehydrated, paraffin-embedded, and serially sectioned at 4 μm thickness each. The serial sections were then stained with Periodic acid-Schiff (PAS). Furthermore, SEM analysis was performed on the same slide of one previously histologically investigated tooth to acquire more details on the structures stained by the PAS method obtained from the histological procedures. Afterward, some American Type Culture Collection (ATCC) strains, smeared on glass slides, were stained following the staining method used in histological samples. Stained rod and cocci forms by PAS stain, observed under light microscopy, were predominantly detected inside dentinal tubules and root canal space of histologically examined specimens, suggesting their bacterial origin. Additional SEM analysis on the identical histological stained slide showed the precise nature of these forms (bacteria) and supplemental information regarding their vitality status. In addition, ATCC smeared strain samples showed variable PAS stainability of microorganisms investigated. Due to its properties, the PAS
histochemical stain could be a valid and helpful aid for non- or weakly stainable microorganisms in infected tissues to be associated with other methods of investigation.
... Concepts from botany, agriculture and microbiology which serve to explain the process were considered in the design, and collaboration from teachers of these courses was received. Experimental classes such as this can be a welcome addition to any curriculum, even those pertaining to other educational levels such as secondary school, since students who take them are better able to consider research from a critical standpoint as well as to assimilate knowledge and understand its potential applications, among other crucial cognitive skills (Gasper and Gardner 2013;Petersen and McLaughlin 2016). ...
The curriculum for undergraduate Agricultural Engineering does not usually include much laboratory practice. In order to address this, here we propose the design of a practical class on legume-rhizobia symbiosis, using an interdisciplinary approach that takes elements from botany, agriculture, and microbiology. The students perform an assay to stimulate nodulation in chickpea seedlings through inoculation with Mesorhizobium strains recommended as commercial inoculants, and evaluate improve-ment in plant growth as a result of nitrogen fixation. The experiment could serve as a springboard to discuss the importance of plant-bacteria interactions in the cultivation of a regionally relevant crop. It may also encourage the use of abilities of different kinds, including the appropriate manipulation of lab materials, the active engagement of scientific thought, the application of knowledge to specific real world scenarios and collaborative teamwork, all of which will be of paramount importance throughout the students’ careers. The class can be easily adapted for other degrees connected to environmental microbiology, as well as for other symbiotic pairs that may include significant crops from other regions around the world.
... Gram staining was conducted followed by the method described by Petersen et al. (2016) Preservation of bacterial isolates in pure culture form: To use the prepared pure culture as a stock culture, it was stored at -20ºC after adding equal volume of 80% glycerin. ...
The study was accomplished to investigate Escherichia coli from two freshwater fish, Tilapia (Oreochromis niloticus) and Mrigal (Cirrhinus mrigala), collected from a fish farm in Sylhet, Bangladesh. Six of each fish were analyzed to isolate and detect Escherichia coli, and E. coli was identified based on morphological and biochemical characteristics. The antibiogram of E. coli was investigated in different generations using eight antibiotic discs such as Chloramphenicol (CH), Streptomycin (S), Gentamycin (G), Ciprofloxacin (CI), Co-trimethoxazole (CO), Azithromycin (AZI), Erythromycin (E) and Novobiocin (NV), and the sensitivity of E. coli was found as 100%, 25%, 100%, 75%, 87.5%, 81.25%, 0%, 0% respectively. Among the 8 antibiotics, for Erythromycin (E) and Novobiocin (NV), the observed resistance pattern of E. coli was 81.25% and 87.5% respectively, whereas, for the rest of the antibiotics, it was 0%. Bangladesh J. Zool. 48(2): 335-346, 2020
... Queensborough Community College (QCC) is an open-enrollment urban community college located in Queens, New York. The Microbiology laboratory class format in QCC's Department of Biological Sciences and Geology is similar to contemporary course syllabi at many 2-and 4-year schools (1,2). As in most Microbiology lab courses, practical exams are administered to assess students' abilities to perform the techniques and skills they learned in the laboratory and apply their theoretical knowledge to practical laboratory situations. ...
Identification of unknown bacteria is an integral module in most introductory Microbiology laboratory courses. This laboratory activity typically involves identifying bacteria based on Gram staining for morphology and gram reaction followed by studying their biochemical characteristics. When instruction moved to online mode earlier this year due to the pandemic, we faced the challenge of moving this hands-on, skill-intensive laboratory activity to remote mode. Here we describe the modular approach we designed to implement the midterm practical of bacterial identification remotely while trying to keep the online format as close to the in-person format as possible in a multi-section synchronous laboratory course. This virtual module was implemented successfully in the summer and fall 2020 semesters.
... Experimental laboratory practices around this issue, then, would greatly contribute to their learning process. Students learning from experimental classes are better able to develop a critical mindset towards research, to take in knowledge, and to understand its potential applications, among other crucial cognitive skills (Petersen and Susan 2016;Caspers and Roberts-Kirchhoff 2003). ...
Despite the growing importance of agricultural microbiology at the applied, productive and ecological levels, undergraduate degrees in Agronomy generally do not feature much microbiological experimentation. To address this deficiency, we have designed an experimental programme that evaluates the potential of plant growth-promoting rhizobacteria (PGPR) for the biocontrol of fungal pathogens. The approach involves an experimental laboratory class in which Agronomy students evaluate the ability of a rhizospheric Burkholderia sp. strain to inhibit the development of Sclerotium rolfsii (the causal agent of 'white wilt' disease in peanut plants). The assays cover three aspects: biochemical mechanisms associated to biocontrol properties in the bacterium, bacterium-fungus interaction (plate inhibition assays), and plant-bacterium-fungus interaction (disease control assays). Students verify the bacterial strain's ability to produce fungi-degrading enzymes, inhibit fungal growth, and protect the plant by inhibiting disease development. The assays serve as an integrative basis on which to discuss relationships between plants, bacteria, and fungi in connection with a disease which affects important regional crops. This set of experiments should help students to develop different skills which will be key in their future professional career, such as handling and designing experimental assays; comparing, discussing and solving practical problems; and drawing conclusions from their observations and the results obtained.
... The studied bacterial isolates were provisionally identified on the basis of the results of morphological test such as Gram staining. Gram staining was performed using compound microscope according to the procedure described by Petersen et al., 2016 [8] . The gram positive and gram negative bacteria were identified based on violet and pink color respectively. ...
Vibrio is the most common genera associated with crustaceans and often causing significant economic losses. Many Vibrio species are pathogenic to human and have been implicated in food borne diseases. The present study was conducted to identify Vibrio spp. from the tiger shrimp (Penaeus monodon) of shrimp pond at Satkhira, Bangladesh. A total number of 33 Vibrio species isolates were identified from 20 shrimp samples through a series of morphological, physiological and biochemical tests. The work reports the prevalence of Vibrio spp. in the pond environments and the existence of three Vibrio species such as V. alginolyticus, V. parahaemolyticus and V. harveyi were identified. In the study of antibiogram, all isolates were shown 100% sensitive to streptomycin, ciprofloxacin and chloramphenicol. Maximum 41% isolates were shown resistant to co-trimethaxozole whereas 30% and 24% resistant to azithromycin and novobiocin respectively.
Analytical Techniques in Biosciences: From Basics to Applications presents comprehensive and up-to-date information on the various analytical techniques obtainable in bioscience research laboratories across the world. This book contains chapters that discuss the basic bioanalytical protocols and sample preparation guidelines. Commonly encountered analytical techniques, their working principles, and applications were presented. Techniques, considered in this book, include centrifugation techniques, electrophoretic techniques, chromatography, titrimetry, spectrometry, and hyphenated techniques. Subsequent chapters emphasize molecular weight determination and electroanalytical techniques, biosensors, and enzyme assay protocols. Other chapters detail microbial techniques, statistical methods, computational modeling, and immunology and immunochemistry.
The book draws from experts from key institutions around the globe, who have simplified the chapters in a way that will be useful to early-stage researchers as well as advanced scientists. It is also carefully structured and integrated sequentially to aid flow, consistency, and continuity. This is a must-have reference for graduate students and researchers in the field of biosciences.
Aeromonas hydrophila infection can cause mass mortality fish and result economic losses for farmers. These is bacterium secretes substances or compounds that support its virulence by producing toxins and extracellular proteins in the form of enzymes. This study aimed to determine the activity of β-hemolysin toxin, DNase enzyme and gelatinase enzyme of A. hydrophila isolated from catfish (Clarias batrachus) in Sidoarjo. This research was carried out in November 2020 in Dukuh Tengah Village, Buduran District, Wedoro Village, Waru District, Wadung Asri Village, Waru District and Keboan Sikep Village, Gedangan District. The sampling technique was carried out by researchers by following activities in the field and visiting correspondents directly in the catfish cultivator ponds, then the catfish samples were carried out by biochemical tests and toxin and enzyme activity tests to obtain the information and data needed. The results showed that A. hydrophila bacteria in catfish produced positive β-hemolysin toxin, DNase enzyme and gelatinase enzyme. The conclusion of the research was that 10 isolates of A. hydrophila bacteria isolated from catfish (Clarias batrachus) in Sidoarjo showed the activity of β hemolysin toxin, DNase enzyme and gelatinase enzyme.
