[Studies on submerged fermentation of alkaline beta-1,4-glycanases by Bacillus pumilus A-30]

The effects of stirring rate, pH control and feed time of (NH4)2SO4 on beta-1,4-glycanases were investigated. The operating conditions of batch fermentation and fed-batch culture were optimized. The results showed there were a large amount of bacterial cells adsorbing on the surface of wheat bran, and stirring rate had a pronounced influence on the adsorption and the production of beta-1,4-glycanases. The uncontrolled pH could promote the induction of beta-1,4-glycanases. When (NH4)2SO4 was fed at a constant rate in the earlier age, and regulated later by determining the content of (NH4)2SO4, xylanase and CMCase activity could reach 616 IU/mL and 1.33 IU/mL respectively.