Enhanced production antibiotics using green gram husk medium by Streptomyces sp. SD1 using response surface methodology

Abstract

Discovery of various antibiotics from the genus Streptomyces attained good attention from Industrialists and Pharmacologists. Streptomyces sp. produce various antibiotics to treat various diseases. The ability of Streptomyces sp. SD1 to synthesize antibiotics using various agro industrial wastes as solid substrate was evaluated. The agro wastes used were pineapple peel, wheat bran, apple pomace, rice bran, tapioca powder, orange peel and green gram husk for the production of antibiotics. The culture medium was optimized by using various carbon, nitrogen, ions, and minerals. To enhance maximum metabolite production, fermentation of Streptomyces sp. SD1 was optimized through response surface methodology. RSM is also used to analyze the interactions among the factors and screening the culture medium components. Streptomyces sp. SD1 had the ability to produce antibiotics at highest level with green gram husk as the substrate. Among the carbon sources, starch, and maltose enhanced the production of antibiotics. However, the selected sources such as, sucrose and glucose negatively influenced on antibiotics production. Beef extract, peptone and yeast extract positively influenced on antibiotics production. However, addition of casein and oat meal inhibited the production of antibiotics. Among the divalent ions, calcium chloride, magnesium sulphate and manganese chloride enhanced the production of antibiotics, however supplementation of cobalt chloride and mercuric chloride affected antibiotics production. All selected mineral sources enhanced the production of antibiotics and the yield was higher than control. 3D response surface graphs showed maximum yield of antibiotics at higher concentration of selected nutrient sources. Antibiotics production enhanced 2.9 fold by Streptomyces sp. SD1 in optimized medium than unoptimized medium. Among the isolates, Streptomyces sp. SD1 showed high antimicrobial activity. The selected actinomycetes utilized green gram husk for antibiotics production. Also addition of nutrient sources stimulated the production of antibiotics. Green gram husk is highly useful for the production of antibiotics in large scale.