产漆酶真菌的筛选与发酵工艺优化

Screening of Laccase Production Fungus and Optimization of Fermentation Conditions

对自行分离的产漆酶真菌菌株Z7,以稻草粉作为碳源进行液体发酵培养,并用响应面法优化发酵工艺。使用Design Expert 8.0.5进行实验设计,首先用PB法筛选出3个主要因子:(NH_4)_2SO_4(氮源)用量、pH、接种量。设计最陡爬坡实验获得各因素的中心值:接种量5%、氮源用量0.15 g·L^(-1)、pH 5。运用BBD设计进行优化实验的设计和分析,获得三个因子的最佳发酵条件:接种量5.53%、氮源用量0.1725 g·L~(^(-1))、pH 5.31,其余因子为温度28℃、装液量50 mL、摇床转速150 r·min^(-1)、培养时间168 h,此时漆酶酶活为801.364 U·mL^(-1)。经验证实验证明该最优水平组合可行。

In this study,Plackett Burman(PB)design and Response surface method(RSM)were employed to optimize thefermentation process. Design Expert 8.0.5 software was used for experiment design. Firstly,three major factors,i. e.,(NH_4)_2SO_4(nitrogen source)level,p H and inoculation amount,were determined and their central values were acquired using steepest ascentdesign as follows: inoculation amount 5%,(NH_4)_2SO_40.15g/L and pH 5. Then,the optimal levels of three key factors werecalculated through the use of the Box-Behnken design(BBD): inoculation amount 5.53%,(NH_4)_2SO_4 0.1725 g/L and pH 5.31. Theother factors included temperature 28℃,liquid volume in flask 50 mL/250 m L,shaking speed 150 r/min,incubation time 168 h,and with these parameters,the maximum theoretical laccase fermentation yield was 801.364 U/m L. This verification test proved thatthe formula was feasible.