An increase in primary productivity is recorded annually during the southwest monsoon season along the west coast of India, an important upwelling zone. The influence of the seasonal variations in the in-situ primary productivity on the bacterial dynamics and community structure was explored during the non-monsoon and productive monsoon seasons. In the monsoon season, distinct upwelling signals and a significant, positive correlation of bacterial carbon (p < 0.01) with primary productivity was observed. Bacterial diversity was also assessed in the chlorophyll maxima depths during both seasons based on metagenomics analysis. In the non-monsoon season, genera such as Idiomarina, Salinimonas, Marinobacter of Proteobacteria and Bacillus and Lactobacillus of Firmicutes were dominant. These major bacterial genera are shown through CCA to play an important ecological role. They are possibly responsible for the increased heterotrophic activity recorded through predicted functional gene profiles in this season. In the monsoon season, increased abundance in the autotrophic Cyanobacteria community and its photosynthetic activity was recorded in the gene profiles. Higher diversity of heterotrophic phyla such as Bacteroidetes, Actinobacteria and a few Candidatus phyla and changes in the diversity of Proteobacteria with a representation of Alteromonas, SAR86 clade and OM60 (NOR5) were also observed. These results highlight the bacterial dynamics associated with seasonal variations in primary productivity.

Understanding the functional profiles of cultivable bacterial communities is crucial for comprehending their ecological significance in marine environments. This study investigates the functional profiles of cultivable bacterial communities in the water and sediments during the productive, southwest monsoon season, along the west coast of India. The southwest monsoon plays a vital role in shaping the hydrological and biogeochemical characteristics of this region, making it an ideal period to study bacterial communities and their functions. Our study utilizes a cultivation techniques to study taxonomy as well as functional assays to elucidate the diverse organic substrates utilization capabilities of bacterial communities. Cultivable bacteria were isolated from discrete water depths and sediment samples from the coastal and off-shore region. Subsequently the carbohydrase, lipase and protease assays were performed to assess its functional potential. The results of this study reveal a rich diversity of cultivable bacterial communities including, representative from Proteobacteria, Firmicutes and Actinobacterial phylum with diverse functional profiles. The functional analyses provide insights into the metabolic capabilities of the bacteria, including organic substrates degradation, processes. The bacterial taxonomic diversity and enzymes activities were significantly different (p < 0.001) among the water and sediment bacterial morphotypes. In conclusion, this research sheds light on the functional profiles of cultivable bacterial communities in the water and sediments along the west coast of India during the productive southwest monsoon season. The comprehensive analysis of their functional capabilities provides insights into their ecological roles and potential significance in organic matter recycling. These findings contribute to our understanding of microbial diversity and ecosystem functioning in coastal environments and lay the groundwork for further research on harnessing the significance of these bacteria in biogeochemical cycling.

No abstract

The current scientific study focuses on the effects of gamma irradiation on fungal isolate Aspergillus occultus MN259598 strain to monitor the efficacy of extracellular Copper nanoparticle (CuNP) synthesis using Copper acetate as the starting material through a biological route. This study is a first report of Gamma irradiation being employed in order to document the possible role of irradiational stress in nanoparticles synthesis in Aspergillus occultus MN259598. Gamma irradiation doses of 0.66 Gy, 0.99 Gy, 1.33 Gy, 1.66 Gy and 1.99 Gy were used for the induction of physiological changes. Macromorphological alterations of the mycelia were observed when grown in broth medium. The lethalities and fungal architectural distortions observed as a part of the study profile of micromorphological characteristics of the irradiated organism were documented. The irradiated fungal cell free extracts (CFE) were used for the production of biogenic CuNPs through optimization studies. Simultaneously, the CFE of the wild type strain was also used for the NP synthesis. The particles were characterized employing UV-Visible (UV-Vis) spectrophotometry, Dynamic Light Scattering (DLS), Fourier Transform InfraRed spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X- Ray Diffraction (XRD) analyses. Sizes of the NPs of treated (66.3 nm) and wild type strain (300 nm approx.) were found to differ enormously. The antimicrobial activity of CuNPs was determined using different food-borne pathogenic bacteria namely Escherichia coli, Bacillus cereus and Listeria monocytogenes.

The current scientific study focuses on the effects of gamma irradiation on fungal isolate Aspergillus occultus MN259598 strain to monitor the efficacy of extracellular Copper nanoparticle (CuNP) synthesis using Copper acetate as the starting material through a biological route. This study is a first report of Gamma irradiation being employed in order to document the possible role of irradiational stress in nanoparticles synthesis in Aspergillus occultus MN259598. Gamma irradiation doses of 0.66 Gy, 0.99 Gy, 1.33 Gy, 1.66 Gy and 1.99 Gy were used for the induction of physiological changes. Macromorphological alterations of the mycelia were observed when grown in broth medium. The lethalities and fungal architectural distortions observed as a part of the study profile of micromorphological characteristics of the irradiated organism were documented. The irradiated fungal cell free extracts (CFE) were used for the production of biogenic CuNPs through optimization studies. Simultaneously, the CFE of the wild type strain was also used for the NP synthesis. The particles were characterized employing UV-Visible (UV-Vis) spectrophotometry, Dynamic Light Scattering (DLS), Fourier Transform InfraRed spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X- Ray Diffraction (XRD) analyses. Sizes of the NPs of treated (66.3 nm) and wild type strain (300 nm approx.) were found to differ enormously. The antimicrobial activity of CuNPs was determined using different food-borne pathogenic bacteria namely Escherichia coli, Bacillus cereus and Listeria monocytogenes.