Antifungal activity of Streptomyces longisporoflavus isolated from Lonar Lake against Alternaria solani

Abstract

Actinomycetes were isolated from water samples of Lonar Lake, Buldhana district of Maharashtra, India and screened for their antifungal activity by agar well diffusion method against phyto-pathogenic fungus Alternaria solani. The strain LL-5 showing highest antifungal activity was identified as Streptomyces longisporoflavus on the basis of microscopic and biochemical characteristics. The antifungal metabolite production using S. longisporoflavus was optimized based on optimal incubation period, temperature, initial pH of medium and supplementation of carbon and nitrogen sources. The study revealed that incubation period of 8 days, 30ᴼC, pH 10.0, starch (1%) as carbon source and peptone (0.5%) as nitrogen source are favorable parameters for maximum production of antifungal metabolite by S. longisporoflavus. These results clearly elucidates that S. longisporoflavus isolated from Lonar Lake water sample could be a good source of antifungal metabolite that can be used for management of diseases caused by Alternaria solani.