Abstract:
Production of secondary metabolites by microorganisms is highly influenced by the nutritional and cultural conditions. The objective of the present study was to study the effect of nutritional and cultural conditions on the production of antibacterial metabolite by Streptomyces variabilis strain PO-178 isolated from Western Ghat soil of Agumbe, Karnataka, India. Starch casein nitrate broth was found to be the best medium for production of antibacterial agents by strain PO-178. The temperature 45°C and pH 9 was shown to be optimum for production of bioactive metabolites. Starch and casein was found to be best carbon and nitrogen source respectively. Increasing starch concentration resulted in better production of antibacterial agents. Sodium chloride at concentration 2% influenced maximum production of bioactive agents. The presence of all trace salts was required for better production of antibacterial agents. It is clear from the study that the production of bioactive agents by strain PO-178 is influenced by several nutritional and cultural conditions. Further, statistical approaches can be conducted to obtain the possible combinations of these conditions for better production of antibacterial agents.

Keywords: Streptomyces variabilis, Nutritional, Cultural, Agar Well Diffusion.