产朊假丝酵母分批发酵生产谷胱甘肽的代谢通量分析

Metabolic flux analysis of glutathione biosynthesis with batch culture of Candida utilis

根据产朊假丝酵母利用葡萄糖作为惟一碳源生物合成谷胱甘肽的代谢网络,利用代谢通量分析方法分析了谷胱甘肽分批发酵不同阶段各代谢途径碳通量的分布和变化规律.在此基础上,通过分阶段温度控制和L-半胱氨酸添加等策略,调节谷胱甘肽分批发酵过程中的代谢通量分布,谷胱甘肽生物合成的产量明显提高,最大增加幅度分别达到23%和91%·同时对这些策略下谷胱甘肽的过量合成机理进行了解释.

The metabolic network of Candida utilis WSH 02-08 for GSH biosynthesis, with glucose as the sole carbon source, was developed based on the stoichiometric balance equations to illustrate the carbon flux distribution of intermediates and metabolites. The metabolite flux distribution and alteration among pathways during diverse batch culture phases were calculated by using the metabolic flux analysis method. Subsequently, the carbon flux of glutathione biosynthesis was adjusted by two-stage temperature control of switching temperature from 30℃ to 26℃ in 8 h, or addition of 8 mmol · L^-1 L-cysteine to the culture broth in 14 h. It was indicated that the production of glutathione was increased by 23% and 91%, respectively. Moreover, the mechanisms of the over-production of glutathione with the above-mentioned culture strategies were interpreted with the principles of metabolic engineering.