MOLECULAR CHARACTERISATION AND ANTAGONISTIC POTENTIAL OF MANGROVE STREPTOMYCES ISOLATED FROM COASTAL REGIONS OF ANDHRA PRADESH, INDIA

The main aim of the present study is to isolate and identify potent actinobacteria from mangrove sediments of SPSR Nellore district, Andhra Pradesh, India along with their antimicrobial activity. The samples collected were initially pretreated with calcium carbonate followed by dry heating. Dilution plate technique was employed to isolate actinobacteria employing two selective media viz. yeast extract malt extract dextrose agar (YMD) and starch casein agar (SCA) amended with NaCl (4%). The media were supplemented with streptomycin (25μg/mL) and nystatin (25μg/mL) to inhibit the growth of bacteria and fungi. Over all 10 strains (VLKK-1 to VLKK-10) were isolated and screened for antimicrobial activity. The potent strain was identified as Streptomyces carpaticus (Gen bank accession number: OR144182) by polyphasic taxonomy including morphological, cultural, physiological and biochemical characters along with 16S rRNA analysis. The growth pattern of the strain was studied by culturing in YMD broth. The culture broth was extracted with ethyl acetate (1:1) and tested for antimicrobial activity against Pseudomonas aeruginosa, Escherichia coli, Candida albicans and Aspergillus niger. The results of this study suggested that the mangrove actinobacteria from the South Indian coast could provide lead compounds of medicinal value.