用响应面法优化油茶籽壳发酵产羧甲基纤维素酶的条件

Optimization for cellulase production by fermentation of camellia testa using response surface approach

以羧甲基纤维素酶(Carboxymethyl cellulase enzyme,CMCase)的酶活力作为响应值,用响应面法对康宁木霉利用油茶籽壳发酵产纤维素酶的发酵条件进行优化。在油茶籽壳预处理方法、氮源、起始pH、发酵时间、接种量、营养液体积对CMCase酶活力单因素试验的基础上,筛选出主要影响因素培养时间、起始pH和营养液体积进行正交试验,通过Box-Behnken设计,利用Design Expert软件进行回归分析,得出3种因素的交互作用及最佳发酵条件。结果表明,用碱法处理油茶籽壳较为适宜;油茶籽壳发酵产纤维素酶的适宜氮源为0.2%的(NH4)2SO4;其他适宜条件为接种量5%、初始pH5.8、营养液体积22 mL、发酵时间5 d。在此条件下,CMCase的酶活力达179.15 U/mL,比单因素试验最高酶活力提高了24.52%。

Fermentation conditions were optimized by taking Carboxymethyl cellulase enzyme（CMCase） activity as a response indicator for cellulase production from Trichoderma koningii using response surface method（RSM）. Three factors that affecting CMCase activity were screened out among pretreatment methods of raw material, nitrogen sources, initial pH values, amount of inoculation, days of fermentation and volume of liquid, they were days of fermentation, initial pH values, and volume of liquid. The optimum conditions of fermentation and their interaction of the three factors were determined through Box-Behnken design and regression analysis using design expert software. The results showed that the CMCase activity could reach 179.15 U/mL, increased by 24.52% under the following conditions： pretreatment methods of raw material was alkaline treatment, nitrogen source was 0.2%（NH4）2SO4, initial pH value was 5.8, inoculation dosage was 5%, volume of liquid was 22 mL, and day of fermentation was 5 d.