SCREENING OF MARINE ACTINOMYCETES FOR PRODUCTION OF ANTIMICROBIAL SUBSTANCES

Abstract

newline Actinomycetes are characteristic organisms because of their multitasking ability like degradative ability, production of important secondary metabolites like antibiotics, enzymes, etc. which can be useful for human health and welfare. They are able to produce metabolites having novel structure and properties. Marine environment is extreme in nature and is an exhaustible source that has not been properly exploited or underexploited. In the present investigation actinomycetes for the production of antimicrobial substance from different regions of west coast of India like Alibag, Janjira, Goa and Daman were studied. From all these regions water, sand and mud samples were collected. Total 123 actinomycetes were isolated among them 85 isolates were identified up to species level while remaining 38 were identified up to genus level. Actinomycetes were identified on the basis of morphological, cultural and biochemical characteristics by using Bergeys Manual of Systematic Bacteriology (Vol.4) and members of genus Streptomyces were identified by PIB Win software. All actinomycetes isolates were placed under following genera: Streptomyces, Micropolyspora, Streptoverticillium, Actinoplanes, Nocardia, Microbispora, Saccharopolyspora, Dermatophilus, Nocardiopsis, Actinomadura, Actinopolyspora, Nocardiodus, Streptosporangium, Intrasporangium and Micromonospora. Streptomyces was found dominant followed by Micropolyspora. All the isolate were studied for their antimicrobial activity against test organisms and found that out of 123 actinomycetes isolates 71 isolates were found to antagonistic against Gram positive bacteria, 47 isolates showed antagonistic activity against Gram negative bacteria while 51 isolates showed antifungal activity. The potent antimicrobial substance producer actinomycetes were identified as Streptomyces sp. on the basis of 16 S rDNA analysis. The potent antimicrobial substance producing actinomycetes was studied for optimization studies for various parameters like pH, temperature, salt conce