PRODUCTION AND CHARACTERIZATION OF ANTIBIOTICS FROM SOIL-ISOLATED ACTINOMYCETES

Abstract

In the present study, the soil samples were collected from various places in the Coimbatore, near drainage, mud and coloured soil where there were no plants around. Actinomycetes strains were isolated in specific medium using soyabean casein digest (SBCD) medium. These Actinomycetes were screened with regard to potential against Gram-positive and Gram-negative bacteria. The purified Actinomycetes strains were performed in biochemical tests. Crowded plate technique was used for the isolation of actinomycetes in media such as soybean – casein digest medium and actinomycetes isolation agar. In a medium formulation study, A-5 and A-5 actinomycete mutant strains were evaluated for maximum antibiotic production using various carbon and nitrogen sources. Zone of inhibition and packed cell volume were the parameters used for the evaluation. Various fermentation conditions such as pH, temperature and dissolved oxygen were also optimized for maximal production of antibiotic from both A-5 and A-5 mutant. Findings from this investigation reveal that strain A-5, in that order, exhibited superior antimicrobial activities to other soil isolates of actinomycetes.