Production of xylanase from Streptomyces sp. M-83 using cost-effective substrates and its application in improving digestibility of monogastric animal feed

An alkalophilic Streptomyces sp. M-83, isolated from the decaying flowers of Bombax ceba, produced alkalo-thermostable xylanase, amylase and phytase when grown on wheat bran under submerged fermentation. Use of immobilized cells of Streptomyces on polyurethane foam enhanced xylanase yield by 133 percent over submerged fermentation. In solid state fermentation, using wheat bran, yield of 2911.0 IU xylanase g⁻¹ dry substrate was obtained at substrate-to-moisture ratio of 1:2 in 48 h at 37°C. Glycine and cynacobalamin enhanced xylanase production by 3.5 and 3.2-folds, respectively, under submerged fermentation conditions. In solid state fermentation, L-arginine monohydrochloride and pyridoxine induced 3-fold and 2.78-fold more enzyme production. The partially purified xylanase was optimally active at pH 6 and 60°C. The enzyme was stable for more than 3 h with 60.0 percent retained activity at pH 4.0 to 9.0 and with temperature ranging from 50 to 60°C. The efficiency of crude enzyme in treating chick feed was maximum after 5 h and resulted in 200 and 360 percent increase in the release of reducing sugars and soluble phosphorous, respectively.