响应面法优化油茶籽壳发酵产纤维素酶条件

摘要

Objective] This study was conducted to optimize cameI ia seed sheI fer-mentation conditions for ceI uIase production by Trichoderma koningi using response surface methodoIogy. [Method] Fermentation conditions for ceI uIase production from Trichoderma koningi were optimized with response surface method (RSM) by taking carboxymethyI ceI uIase (CMCase) activity as a response indicator. Three factors that affecting CMCase activity were screened out using singIe factor test among pretreatment methods of raw material, nitrogen sources, initial pH values, inocuIum voIume, fermentation time and voIume of Iiquid medium, they were fermentation time, initial pH value, and voIume of Iiquid medium. The optimum conditions of fer-mentation and interaction of the three factors were determined through Box-Behnken design and regression analysis using Design-Expert software. [Result] Pretreatment of cameI ia seed sheI with alkaline was most conducive to CMCase production. The use of 0.2% (NH4)2SO4 as nitrogen source, inocuIum size of 5%, initial pH value of 5.8 and voIume of Iiquid medium at 22 mI were the best fermentation conditions for maximizing CMCase production by T. koningi from cameI ia seed sheI . Under these conditions, 179.15 U/mI of CMCase was obtalned after 5 d of fermentation, which was improved by 24.52% compared with the maximum CMCase activity of singIe factor test. [Conclusion] The resuIts wiI provide some references for use of cameI ia seed sheI and ceI uIase production.%[目的]研究康宁木霉利用油茶籽壳发酵产纤维素酶的发酵条件。[方法]以羧甲基纤维素酶(Carboxymethyl cellulase, CMCase)活力作为响应值，采用响应面法对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]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2%的（NH4）2SO4；其他适宜条件为接种量5%、初始 pH 5.8、营养液体积22 ml发酵时间5 d。在此条件下， CMCase 酶活达179.15 U/ml，比单因素试验最高酶活力提高了24.52%。[结论]该研究可为油茶籽壳的利用与纤维素酶的生产提供参考。