【摘要】 采用U15*(157)均匀试验对虫源性的蜡状芽孢杆菌产纤维素酶发酵条件进行逐步回归分析;以DNS法测定酶活力,确定了该菌株的最优产酶条件。试验结果表明,在自然供氧条件下,发酵74h时酶活性最高;蛋白胨对纤维素酶活力有促进作用。最佳组合条件为:在100mL三角瓶中装入20mL液体培养基,初始pH值为7.5,0.5%CMC-Na,1.2%蛋白胨,最大酶活为233.4711μg(/mL·min)。进一步的酶学特性研究显示,酶促反应的最适pH值为8.5,最适温度为25℃～60℃,范围内酶活可保持60%以上。更多还原

【Abstract】 U15(157) uniform design was adopted to optimize the submerged fermentation media for cellulase producing by Bacillus cereus which was obtained from the surface of pine wood nematode.Activity of cellulase was assayed by means of dinitrosalicylic acid(DNS).The results showed that:1) The maximum cellulase activity was obvious in 74 h after incubation under natural aeration condition;2) Peptone could improve the the cellulase activity;3) The optimized medium should be 0.5% CMC-Na,1.2% peptone at initial pH 7.5.Under the optimum integrated condition,the activity of cellulase was up to 233.4711μg/ml.min;4) The optimal enzymatic reaction conditions were 50℃ and pH 8.5.Moreover,the 60% cellulase activity would remain at 25℃～60℃ for 30 min,which indicated great potential application in industrial at room temperature.更多还原