高浓度乙醇连续发酵振荡过程中代谢通量分析及诱发机理  

Metabolic flux analysis and mechanistic study of process oscillation in continuous VHG ethanol fermentation with Saccharomyces cerevisiae

作　　者：申渝[1] 葛旭萌[1] 李宁[1] 白凤武[1] 

机构地区：[1]大连理工大学生物科学与工程系,辽宁大连116023

出　　处：《化工学报》2009年第6期1519-1528,共10页CIESC Journal

基　　金：国家高技术研究发展计划项目(2007AA10Z358)~~

摘　　要：在利用普通酿酒酵母进行高浓度乙醇连续发酵的实验中,发现了一种长周期、高振幅的振荡现象。利用流式细胞仪测定了振荡周期不同时点的细胞周期分布,表明这种特殊的振荡现象和酵母细胞周期的同步化不相关。对一个完整振荡周期中不同时点的代谢通量分析,发现胞内碳通量在代谢网络中的分布也呈现出和胞外残糖、乙醇和生物量浓度类似的振荡过程。分析酵母细胞代谢活性与胞外发酵体系乙醇浓度的时程关系,表明酵母细胞对乙醇抑制的延迟反应是诱发这种振荡行为的主要因素,胞内海藻糖积累与乙醇生成同步,进一步支持了这一观点。Process oscillation characterized by a long oscillation period and a large oscillation amplitude was observed in continuous ethanol fermentation with Saccharomyces cerevisiae under very high gravity （VHG） conditions. Flow cytometry was used to determine the cell cycle distributions at different time points in the duration of the oscillation. Analysis for the yeast cell cycle indicated that no cell cycledependent synchronization happened within the duration of the oscillation. Metabolic flux analysis was carried out and the results illustrated that the carbon flux within the metabolic network oscillated correspondingly. Ethanol inhibition and the lag response of yeast cells to ethanol inhibition were experimentally validated to be the root reason triggering this phenomenon, which was further supported by the synchronized accumulation of the intracellular trehalose, a stress-resistant agent.

关 键 词：乙醇连续发酵 高浓度 振荡 代谢通量分析 细胞周期 

分 类 号：TQ920.1[轻工技术与工程—发酵工程]