Antimicrobial and Cytotoxic Activities of an Actinobacteria (Streptomyces Sp. PM-32) Isolated from an offshore

Abstract: A total of one twenty five strains isolated from the offshore sediments of the Bay of Bengal in Tamilnadu were tested for their antimicrobial activity against five Gram-positive, five Gram-negative bacteria and five pathogenic fungi. Of these only 23 strains showed activity against the pathogenic microorganisms and the strain PM-32 was very active. Supernatant was obtained by solvent extraction followed by the chromatographic purification. Spectral data of the purified compound revealed its antimicrobial nature. The fractions showed a steady increase of absorption with the increasing wavelengths of UV-visible light, ranging from 200-500 nm. The BC I fraction showed an additional absorption peak at 249 nm and its minimum inhibitory concentration was between 16 to 74 µg/ml against the tested pathogens. The isolate yielded also showed strong cytotoxicity in brine shrimp lethality assay and the LC value was 0.15µg/ml.5