利用响应面法对Anoxybacillus sp.YIM 342产耐高温α-淀粉酶的液体发酵培养条件进行优化.在单因素试验的基础上,首先应用Plackett-Burman实验设计筛选在发酵过程中对产酶量影响较大的因素,然后利用中心组合设计确定对产酶量影响较大因素的最佳水平.筛选结果表明,淀粉和CaCl2的浓度以及发酵时间对产酶量有显著的影响;最佳发酵条件为:淀粉11.73 g/L,CaCl20.65 g/L,发酵时间为37.27 h,胰蛋白胨5 g/L,MgSO40.5 g/L,起始pH值6.5,转速200 r/min,温度55℃,在此条件下产酶量达到了62.71 U/mL,较初始产酶量提高了3.25倍.
The fermentation condition of thermostable alpha amylase by strain Anoxybacillus sp. YIM 342 was optimized by response surface methodology. Based on the single factor experiment, main factors affecting the enzyme activity were screened during the fermentation by Plackett - Burman design, and the optimum values of the main factors were obtained by central composite design. The results showed that the productivity of the enzyme was affected by incubation time and concentrations of soluble starch and CaC12. The optimized conditions were as follows: starch, 11.73 g/L, CaC12 ,0.65 g/L, incubation time, 37.27 h, tryptone ,5 g/L, MgSO4 ,0.5 g/L, pH 6.5, rotation speed ,200 r/min and temperature ,55 °C. Under these conditions ,the amylase activity was 62.71 U/mL, which was 3.25 times better than before.