响应曲面法优化产外切菊粉酶菌株G-60的发酵条件研究

从新疆石河子盐碱地菊芋生长根际土壤中,分离筛选得到10株具有菊粉外切酶活力的菌株,复筛得到1株高产菊粉外切酶活力菌株,将其命名为G-60.在单因素实验的基础上,采用Plackett-Burman试验法对8个因素进行了显著因素的筛选,结果表明菊粉添加量、酵母膏含量和仞始pH值对菊粉外切酶酶活影响极显著；通过最陡爬坡试验及Box-Behnken设计进一步优化,得到最佳发酵产酶条件为:菊粉添加量7.91％、培养基初始pH为6.61、酵母膏含量0.64％,在此条件下,外切酶活达到58.51U/mL,与优化前相比提高2.02倍.

Response surface optimization for the fermentation condition of exoinulinase production from strains G-60

Ten strains with exoinulinase activity were collected from the root soil of Jerusalem artichoke in Shihezi city of Xinjiang province. A strain with high exoinulinase productivity was screened, named G-60. A Plackett-Burman design was used to evaluate the influence of eight factors. The results showed that inulin added amount, content of the yeast extract and the initial pH value played important roles in influencing the exoinulinase activity, Then the path of steepest ascent and the Box-Behnken design were adopted for further optimization, the optimal concentration of the variables were determined as: inulin 7.91%, initial pH value 6.61, yeast extract 0.64%, and under these conditions, the exoinulinase activity increased to 58.51U/ml, which was 2.02 times compared with before optimization.