OPTIMIZATION OF A CULTURE-MEDIUM FOR XYLANASE PRODUCTION BY BACILLUS SP. USING STATISTICAL EXPERIMENTAL-DESIGNS

The concentrations of oat spelt xylan, casein hydrolysate and NH4Cl in the culture medium for production of xylanase from Bacillus sp. I-101 8 were optimized by means of response surface methods. The path of ste epest ascent was used to approach the optimal region of the medium com position. The optimum composition of the nutrient medium was then easi ly determined by using a central composite design and was found to be 3.16 g/l of xylan, 1.94 g/l casein hydrolysate, 0.8 g/l of NH4Cl. The xylanase production was increased by 135% when the strain was grown in the optimized medium compared to initial medium.