统计学方法优化麦麸发酵产木聚糖酶条件的研究

Optimization of Xylanase Production by Fermentation of Wheat Bran Using Statistical Experimental Designs

以纳豆芽孢杆菌JSU-15为供试菌株,麦麸皮为唯一固体发酵基质,运用统计学方法对其产木聚糖酶的条件进行优化。首先用24-1部分因子实验设计对影响木聚糖酶活性的主要变量进行了评价,发现主要影响因子为粒径和发酵时间。然后用最陡爬坡实验设计确定主要变量的最佳水平。最佳产酶发酵条件为:粒径为0.4 mm、麸皮与水的比例为1∶5.6、接种量为3 mL和发酵时间为50 h。在最佳产酶条件下进行发酵,木聚糖酶活力达367 U/g麦麸,比未优化前提高了2.1倍。

Statistical experimental designs were applied for the optimization of xylanase production by Bacillus subtihs （natto） JSU- 15 in solid - substrate fermentation using wheat bran as a sole substrate. In the first step of optimization, with 24 1 fractional factorial design, particle size and cultivation time were found to be the important factors affecting xylanase production significantly. These two major variables were subsequently optimized using the method of steepest ascent design. The optimal conditions for xylanase production were found to be particle size 0.4 mm, wheat bran to water ratio 1 ： 5.6, inoculum size 3 mL and cultivation time 50 h. Under these optimal conditions, the xylanase production from B. subtilis （natto） JSU - 15 is 367 IU/g （wheat bran）, 2.1 fold higher than that before the optimization.