响应面法优化南极菌Psychrobacter sp.B-3的发酵产糖条件

摘要

The fermentation conditions of exopolysaccharides (EPS) production by Antarctic bacterium Psychrobacter sp.B-3 were optimized in this study.Initially,the most suitable temperature 10 ℃,nitrogen source peptone,salt BaCl2,seawater proportion 2 ∶ 1 and pH 7 were selected respectively according to single factorial experiments respectively.Based on the result,screening methodology Plackett-Burman design was used to evaluate the effects of ten factors related to EPS production and three statistically significant factors yeast extract,seawater proportion and liquid volume were selected.Then,the optimal combined concentration for maximum EPS production was further optimized by response surface methodology.The optimization of culture conditions of Psychrobacter sp.B-3 led to a 40 ％ increase compared to the initial EPS production of 444 μg/mL indicating that the response surface methodology is an effective method for optimization of EPS production conditions for Psychrobacter sp.B-3.%为对南极菌Psychrobacter sp.B-3产胞外糖的发酵条件进行优化,以温度、pH、不同碳源、不同氮源、不同金属离子及海水配比作为唯一变量进行单因素实验,筛选出对产糖有显著影响的单因素取值范围;在此基础上,利用Plackett-Burman实验设计筛选出影响产多糖的3个主要因素,即酵母粉、陈海水配比和装液量.然后通过Box-Behnken实验设计及响应面分析法进行回归分析,得出了南极菌Psychrobacter sp.B-3发酵条件系统优化的结果为:酵母粉1.1 g/L,陈海水与自来水的配比为2:1,装液量为50％,蛋白胨6.0 g/L,接种量1.5％,培养时间64 h,BaCl20.03 g/L,温度10℃,转速150 r/min,pH为7.0.优化后发酵液中的糖含量由优化前的444 μg/mL提高到624 μg/mL,相比初始糖产量提高了40％.结果表明,响应面法可显著优化南极菌Psychrobacter sp.B-3液体发酵产胞外糖的条件.