Studies on isolation and molecular characterization of plasmids from Vibrios

While the seriousness of the problem of antibiotic resistance is now recognized, the complex web of resistance linking humans, animals, and the environment is getting realized. More often, antibiotics are used as a preventive measure against diseases. Antibiotic use for agriculture leads to the increased resistance in the environment since antibiotics are inevitable element during agriculture/aquaculture and antibiotic residues are excreted as waste that is frequently spread onto farmland as organic fertilizer. Fecal bacteria survive long periods in the environment and spread through runoff into groundwater, rivers, and marine ecosystems.However, horizontal gene transfer occurs in the animals and guts of humans and in a variety of ecosystems, creating a pool of resistance in the rice fields and open waters. Even if people are not in direct contact with resistant disease through food animals, there are chances of contact with resistant fecal pathogens from the environment. Additionally, pathogens that are autochthonous to the environment can acquire resistance genes from the environment. Our study revealed that autochthonous , bacteria Vibrio spp gained antibiotic resistance in the environment. Further, it was evident that horizontal gene transfer occurs in Vibrio by means of plasmids, which further augments the gravity of the problem. Non-pathogenic bacteria may also acquire resistance genes and serve as a continuing source of resistance for other bacteria, both in the environment, and in the human gut. As the effectiveness of antibiotics for medical applications decline, the indiscriminate use of in aquaculture and in humans can have disastrous conditions in future due to horizontal gene transfer and the spread of resistant organisms: We must recognize and deal with the threat posed by overuse of antibiotics.

Biochemical and Biotechnological Studies on the Cyanobacterium Synechocystis salina Wislouch

The group cyanobacteria includes a large number of organisms characterised by a low state of cellular organization. Their cells lack a well defined nucleus. Cell division is by division of the protoplast by an ingrowth of the septum. These organisms are characterised generally by a blue green colouration of the cell, the chief pigments being chlorophyll-a, carotenes, xanthophylls, C phycocyanin and C phycoerythrin. The product of photosynthesis is glycogen. These organisms lack flagellate reproductive bodies and there is a total lack of sexual reproduction. They are also unique because of the presence of murein in the place of cellulose (cell wall) and the absence of chloroplast, mitochondria and endoplasmic reticulum. Just like bacteria some of them possess Plasmids and can fix atmospheric nitrogen. In the present study growth kinetics, heavy metal tolerance, tolerance mechanisms, heavy metal intake, and antibacterial activity of §ynechocystics salina Wislouch - a nanoplanktonic, euryhaline, Cyanobacterium present in Cochin back waters has been carried out for the potential biotechnological application of this organism. _§; salina occur as small spherical cells of 3n diameter (sometimes in pairs) with bluish green colour. The species is characterised by jerky movement of the cells and is structrually similar to other cyanobacteria

Characterization and applications of two protease enzymes obtained by culture dependent and independent approaches from mangrove sediments

Soil community genomics or metagenomics is employed in this study to analyze the evolutionary related - ness of mangrove microbial community. The metagenomic DNA was isolated from mangrove sediment and 16SrDNA was amplified using universal primers. The amplicons were ligated into pTZ57R/T cloning vector and transformed onto E. coli JM109 host cells. The recombinant plasmids were isolated from positive clones and the insert was confirmed by its reamplification. The amplicons were subjected to Amplified Ribosomal DNA Restriction Analysis (ARDRA) using three different tetra cutter restriction enzymes namely Sau3A1, Hha1 and HpaII. The 16SrDNA insert were sequenced and their identity was determined. The sequences were submitted to NCBI database and accession numbers obtained. The phylo - genetic tree was constructed based on Neighbor-Joining technique. Clones belonged to two major phyla of the bacterial domain, namely Firmicutes and Proteobacteria, with members of Firmicutes predominating. The microbial diversity of the mangrove sediment was explored in this manner.