玉米秸秆高效糖化菌株筛选及其产酶条件研究

Screening of high efficient strain for corn straw saccharification and conditions of enzyme-producing

高产纤维素酶和半纤维素酶菌株可以有效提高木质纤维素原料制燃料乙醇的产率.研究采用刚果红羧甲基纤维素钠培养基,并结合滤纸条培养基进行初筛,以玉米秸秆粉为发酵培养基进行复筛,筛选到纤维素酶和半纤维素酶高产菌Z-7真菌.采用摇床液体发酵试验并测定纤维素酶活和半纤维素酶活以确定Z-7真菌的最优产酶条件.结果表明,250 mL三角瓶的最佳装瓶量为50 mL,接种量为3%,pH值为5.5,摇床培养温度38℃,最佳产酶时间48 h,在此条件下该菌产CMC-Na酶活达到100 u/mL,半纤维素酶活达到126.6 u/mL.

A high yield cellulase and xylanase strain can play a key role in the conversion of lignocellulosic materials into fuel alcohol. Therefore a high cellulase-producing and xylanaseproducing fungus Z - 7 is isolated using the methods of transparent zone, filter paper degradation and Shaking culture. The optimal enzyme-producing conditions of the fungus Z -7 are as follows： the optimum quantity of inoculation is 3 %, medium volume is 50mL, pH value is 5.5, temperature is 38 ℃ and cultivation for 48 hours. The activities of CMC-Na enzyme and xylanase are as high as 100 u/mL and 126. 6 u/mL under the optimal enzyme-producing conditions, respectively.