Biotechnology
http://irgu.unigoa.ac.in/drs/handle/unigoa/17
2024-03-28T18:14:37ZBacterial diversity and community structure of salt pans from Goa, India
http://irgu.unigoa.ac.in/drs/handle/unigoa/7268
Bacterial diversity and community structure of salt pans from Goa, India
Gawas, P.; Kerkar, S.
In Goa, salt production from the local salt pans is an age-old practice. These salt pans harbor a rich diversity of halophilic microbes with immense biotechnological applications, as they tolerate extremely harsh conditions. Detecting the existence of these microbes by a metabarcoding approach could be a primary step to harness their potential. Three salt pans viz. Agarwado, Curca, and Nerul adjoining prominent estuaries of Goa were selected based on their unique geographical locations. The sediments of these salt pans were examined for their bacterial community and function by 16S rRNA amplicon-sequencing. These salt pans were hypersaline (400-450 PSU) and alkaline (pH 7.6-8.25), with 0.036-0.081 mg/L nitrite, 0.0031-0.016 mg/L nitrate, 6.66-15.81 mg/L sulfate, and 20.8-25.6 mg/L sulfide. The relative abundance revealed that the Pseudomonadota was dominant in salt pans of Nerul (13.9 percent), Curca (19.6 percent), and Agarwado (32.4 percent). The predominant genera in Nerul, Curca, and Agarwado salt pan sediments were Rhodopirellula (1.12 percent), Sulfurivermis (1.28 percent), and Psychrobacter (25.5 percent) respectively. The highest alpha diversity (Shannon-diversity Index) was observed in the Nerul salt pan (4.8) followed by Curca (4.3) and Agarwado (2.03). Beta diversity indicated the highest dissimilarity between Agarwado and the other two salt pans (0.73) viz. Nerul and Curca and the lowest dissimilarity was observed between Nerul and Curca salt pans (0.48). Additionally, in the Agarwado salt pan, 125 unique genera were detected, while in Nerul 119, and in Curca 28 distinct genera were noted. The presence of these exclusive microorganisms in a specific salt pan and its absence in the others indicate that the adjacent estuaries play a critical role in determining salt pan bacterial diversity. Further, the functional prediction of bacterial communities indicated the predominance of stress adaptation genes involved in osmotic balance, membrane modification, and DNA repair mechanisms. This is the first study to report the bacterial community structure and its functional genes in these three salt pans using Next-Generation Sequencing. The data generated could be used as a reference by other researchers across the world for bioprospecting these organisms for novel compounds having biotechnological and biomedical potential.
2023-01-01T00:00:00ZSuperwettable surfaces and factors impacting microbial adherence in microbiologically-influenced corrosion: A review
http://irgu.unigoa.ac.in/drs/handle/unigoa/7269
Superwettable surfaces and factors impacting microbial adherence in microbiologically-influenced corrosion: A review
Rane, D.; Kerkar, S.; Roy, S.R.; Kowshik, M.
Microbiologically-influenced corrosion (MIC) is a common operational hazard to many industrial processes. The focus of this review lies on microbial corrosion in the maritime industry. Microbial metal attachment and colonization are the critical steps in MIC initiation. We have outlined the crucial factors influencing corrosion caused by microorganism sulfate-reducing bacteria (SRB), where its adherence on the metal surface leads to Direct Electron Transfer (DET)-MIC. This review thus aims to summarize the recent progress and the lacunae in mitigation of MIC. We further highlight the susceptibility of stainless steel grades to SRB pitting corrosion and have included recent developments in understanding the quorum sensing mechanisms in SRB, which governs the proliferation process of the microbial community. There is a paucity of literature on the utilization of anti-quorum sensing molecules against SRB, indicating that the area of study is in its nascent stage of development. Furthermore, microbial adherence to metal is significantly impacted by surface chemistry and topography. Thus, we have reviewed the application of super wettable surfaces such as superhydrophobic, superhydrophilic, and slippery liquid-infused porous surfaces as "anti-corrosion coatings" in preventing adhesion of SRB, providing a potential avenue for the development of practical and feasible solutions in the prevention of MIC. The emerging field of super wettable surfaces holds significant potential for advancing efficient and practical MIC prevention techniques.
2024-01-01T00:00:00ZIsolation and Characterization of Cationic Peptides from Selected Plants
http://irgu.unigoa.ac.in/drs/handle/unigoa/7265
Isolation and Characterization of Cationic Peptides from Selected Plants
Sreekala, S.
2022-01-01T00:00:00ZProduction of peptidic antimicrobials by bacterial populations from diverse coastal habitats of Goa, India
http://irgu.unigoa.ac.in/drs/handle/unigoa/7247
Production of peptidic antimicrobials by bacterial populations from diverse coastal habitats of Goa, India
Naik, P.G.; Muraleedharan, U.D.
With conventional antibiotics rapidly losing their efficacy, marine microorganisms found in diverse salinity conditions are being explored for new antibacterial agents. Salinity is a major contributing factor to the distribution of biota in aquatic systems, and little is known about the production of antimicrobials by microbial communities in response to stressful environmental conditions. This work adds to the comprehension of bacterial abundance in estuarine and coastal beach waters of Goa and population structuring concerning their antimicrobial activity as specifically conferred by antimicrobial peptides. Total viable counts indicated higher bacterial load in estuarine water environments than in the higher salinity waters, suggesting a role of salinity variation as a driver of community composition in these habitats. In total, 82 bacterial isolates were selected, and the overall proteinaceous content in their exudates were screened for antimicrobial activity against Salmonella typhimurium (MTCC 91), Staphylococcus aureus (MTCC 3160), Escherichia coli (MTCC 443), Candida albicans (MTCC 227) and Aeromonas hydrophila (MTCC 1739), by the agar well diffusion method. Of these, 51.8 percent showed activity against S. typhimurium, 30.3 percent against S. aureus, 13.9 percent against E. coli, 8.8 percent against C. albicans, and 7.5 percent against A. hydrophila. Compared with estuarine bacteria, those from more saline waters showed higher production of potent antimicrobial peptides, which were probably used to counter the high competition for resources. Such sites could, therefore, be potential niches for bioprospecting of microbes producing bacteriocin-like compounds.
2023-01-01T00:00:00Z