裂殖壶菌发酵产DHA过程呼吸参数的在线检测分析

Online analysis of respiratory parameters in fed-batch fermentation process for DHA production by Schizochytrium sp.

利用尾气分析仪对发酵过程的尾气中的O2、CO2含量进行实时检测,建立了裂殖弧菌发酵生产DHA过程中的呼吸参数在线检测方法,实现了裂殖壶菌补料分批发酵过程及双阶段供氧控制发酵过程中的呼吸参数在线检测分析。通过呼吸参数在线检测分析,从氧消耗机制方面解释了双阶段氧传递控制工艺能获得较高生物量、油脂和DHA含量的原因,从而为该工艺过程提供了理论指导。根据发酵过程中菌体生长不同时期的呼吸参数的变化情况,建立了基于呼吸商变化的在线补料控制方法,设计了一种基于RQ-Stat的补料工艺。RQ-Stat补料方式最终获得的油脂含量、DHA产量和产率比间歇式补料工艺分别提高了11.58%、12.19%和11.40%。

A method for online analysis of respiratory parameters in fermentation process for DHA production by Schizochy-trium sp. was developed by detecting the concentration of oxygen and carbon dioxide in the exhaust gas online using exhaust gas analyzer. Online analysis of the respiratory parameters in fed-batch fermentation process and two-stage oxygen supply fed-batch process was accomplished. The theoretical explanation for the improvement of biomass, lipids and DHA content was made by using respiratory parameter online analysis, providing theoretical guidance for the two-stage oxygen supply process. In addition, according to the change of respiratory parameters in different growth periods of fermentation process, the online automatic feeding control method based on changes in respiratory quotient was built and a RQ-Stat feeding process was designed. The fermentation results of lipids and DHA content and DHA productivity were increased by 11.58% ,12. 19% , and 11.40% ,higher than that of the pulse feeding process.