Optimization of cultural conditions for cellulase-free xylanase production by mutant strain of alkalophilic Cellulosimicrobium sp. CKMX1 in submerged fermentation

This paper reports optimization of cultural conditions for xylanase production by mutant strains of Cellulosimicrobium sp. CKMX1 in submerged fermentation. Alkalophilic Cellulosimicrobium sp. CKMX1, capable of producing xylanase, was isolated from mushroom compost. Xylanase production by this strain was enhanced by ethyl methanesulfonate (5–70 mg mL⁻¹) mutation and by optimizing the process parameters in submerged fermentation. Mutant strain E₅ with hyper xylanase production was obtained after treating wild strain with ethyl methanesulfonate on the basis of xylanase activity index and xylanase activity in liquid medium. Cultural conditions were optimized for parent and mutant strain and incubation period of 72 h, incubation temperature of 35±1C, pH of 8.0; 1% inoculum size: and xylan as carbon source yielded high xylanase. Mutant E₅ was 22.99% more efficient than parent strain. Results indicated the potential of alkalophilic Cellulosimicrobium sp. CKMX1 and its hyper xylanase producing mutant strain E₅ to be promising for pulp and paper industry.