齐整小核菌发酵产硬葡聚糖的补料控制策略

Strategies for feeding control in microbial production of scleroglucan by Sclerotium rolfsii WSH-G01

为促进齐整小核菌(Sclerotium rolfsii WSH-G01)利用葡萄糖生产硬葡聚糖,在确定了最优搅拌转速的基础上,研究了2种补料方式对菌体生物量和多糖产量的影响。确定了控制搅拌转速400 r/min;发酵40 h时开始,恒速流加补料葡萄糖总浓度400 g/L,流速6 g/(L·h),补料维持时间32 h的补料策略是最佳补料调控策略。结果表明,此种补料方式在齐整小核菌发酵72 h时获得最高硬葡聚糖产量32. 62 g/L,生物量22. 36 g/L,生产强度0. 45 g/(L·h),底物利用率28%。多糖产量较另一种补料方式提高了15%,较分批发酵提高了76. 5%。

In order to improve the production of scleroglucan by Sclerotium rolfsii WSH-G01 using glucose as the substrate,on the basis of the optimal stirring speed,the effects of two feeding methods on biomass and titer of polysaccharides were studied.The stirring speed was 400 r/min.The best feeding strategy was maintaining the feeding speed of 6 g/(L·h)for 32 h after 40 h of fermentation when the total glucose concentration was 400 g/L.The results showed that the highest titer of polysaccharide(32.62 g/L),the biomass(22.36 g/L),the productivity(0.45 g/(L·h)),and the substrate utilization rate(28%)were reached at 72 h.The polysaccharide production was 15%higher than that obtained using the other feeding method and increased by 76.5%compared with batch fermentation.