Influence of nutrition and culturing conditions for optimum growth and antimicrobial metabolite production by Streptomyces sp. 201

Abstract

Summary Objective To evaluate the effects of certain nutrients and influence of environmental parameters on growth and production of bioactive metabolite by Streptomyces sp. 201 in submerge culture. Material and methods Disc diffusion method was employed to study the effect of different culture media, various carbon and nitrogen sources, inoculum size, temperature, pH and incubation period on the production of bioactive metabolite in flask cultures by Streptomyces sp. 201. Growth was determined as dry mycelial weight in a fixed volume of culture broth. Results Mannitol and asparagine were found to be the most suitable carbon and nitrogen sources respectively, for optimum production of growth and bioactive metabolite by the isolate. Optimum production of bioactive metabolite required mannitol in the cultivation medium with a concentration of 1.5 g/l. On the other hand, the highest antibiotic production was obtained in a cultivation medium containing 0.9 g/l of asparagine. Maximum production of bioactive metabolite in a synthetic medium was found on the sixth day of incubation. Furthermore, maintaining the incubation temperature at 30 o C, pH 7.5 and the inoculum size of 2 × 10 9 spores per millilitre under shaking condition was found to be optimum for maximum antimicrobial activity. Conclusion The production of antimicrobial metabolite could be optimized in culturing conditions of Streptomyces sp. 201.