响应面法优化青枯病生防菌Hrp~-菌株的发酵条件

对工程菌Hrp-菌株的摇瓶发酵条件进行优化。首先采用Plackett-Burman设计法对影响Hrp-菌株活菌量的6个因素进行评价,筛选出具有显著效应的2个因素(发酵温度和摇床转速),再用最陡爬坡试验法接近重要因子的最优水平,最后应用中心组合设计确定重要因子的最优水平。确定优化后的发酵条件:初始pH 8.75、装液量为100 mL(500 mL三角瓶)、接种量6.25%、接种龄10 h、温度20℃、摇瓶转速205 r/min。实验结果表明:采用优化后的发酵条件,Hrp-菌株的发酵液菌量由最初的3.30×1010个/mL提高至4.42×1010个/mL,增幅为133.9%。

Optimization of fermentation conditons for Hrp-mutant of Ralstonia solanacearum as biocontrol agent of bacterial wilt using response surface methodology

Optimization of fermentation conditions for Hrp-mutant of Ralstonia solanacearum was conducted in flask.Temperature and shaking rate affecting the biomass of Hrp-mutant were screened out by applying Plackett-Burman design.The path of steepest ascent was used to approach the optimal levels of the two important factors.The optimal levels were determined by the central composite design.The optimized fermentation conditions were as follows:inoculation time 10 h,fermentation temperature 20 ℃,initial pH 8.75,inoculation concentration 6.25%,flask column 100 mL in 500 mL flask,and shaking rate 205 r/min.Under the optimal conditions,the bacterial biomass increased from 3.30×1010 to 4.42×1010 cfu/mL,an increase of 133.9%.