Optimization of media for production of bioactive compounds by Streptomyces parvullus SS23/2 isolated from marine algae in the Bay of Bengal, India

Abstract

Streptomyces are economically and biotechnologically valuable prokaryotes responsible for production of bioactive secondary metabolites, notably antibiotics, antitumor agents, immunosuppressive agents and enzymes. The present study deals with the optimization of media for production of bioactive compounds from Streptomyces parvullus SS23/2 isolated from marine algae (Dictyota dichotoma) at the Bay of Bengal, India. Suitable medium was selected and optimized under different chemical and physical parameters for maximum production following one-factor- at- a time approach. Optimum condition for initial pH, medium capacity, inoculum size, inoculum age, agitation and growth period were assessed and the result was found to be optimum at 7, 50 ml, 7.5% (v/v), 48 hours, 180 rpm and 6 days, respectively. Component of the best carbon source for the basal medium was sucrose at 2% and 1.5% concentration for bacteria and fungi, respectively. Malt extract at 1% concentration was the best nitrogen source for both bacteria and fungi. The composition of the best medium for Streptomyces parvullus SS23/2 was (g/l: Corn steep liquor, 10, sucrose, 20; malt extract, 10; K₂HPO₄, 5; NaCl, 2.5; ZnSO₄, 0.04; CaCO₃, 0.4; pH=7). After optimization, antimicrobial activity was improved from 36 mm to 40.7 mm inhibition zone against B. subtilis. In the research for bioactive compounds, screening, characterization and optimization of the media and cultural conditions are important for strain improvement. Therefore, optimization of products from Streptomyces in different samples may create a great potential for upscaling secondary metabolites such as antibiotics and might remain an area of research interest in the future antibiotic discovery.

Keywords/phrases: B. subtilis, Marine sediment, Optimization, Streptomyces parvullus

Ethiop. J. Biol. Sci. 11(1): 1-11, 2012