基于代谢途径分析的重组大肠杆菌BG20胞苷发酵条件的研究

Study on fermentation condition based on analysis of cytidine biosynthesis pathway in recombinant Escherichia coli BG20

胞苷是一种嘧啶核苷,主要用于生产药物的中间体。以重组大肠杆菌BG20为研究对象,对胞苷发酵条件进行了研究。首先分析了大肠杆菌中胞苷的生物合成途径,并根据胞苷合成的需要对发酵条件进行了优化设计;采用正交试验设计对初始葡萄糖浓度、硫酸铵、磷酸盐及p H、温度、溶氧控制等发酵条件进行了研究。结果表明,在500 m L摇瓶发酵条件下,得到胞苷发酵的最佳发酵培养基组分为:初始葡萄糖浓度160 g/L、硫酸铵浓度1.3%、磷酸盐浓度2.2%,最佳发酵条件为:温度38℃、转速180 r/min、p H7.2;对比分析了优化前后对菌体生长与胞苷产量的影响,胞苷的积累量达到0.2835 g/L,较优化前提高了61.4%。

Cytidine is a kind of pyrimidine nucleoside, mainly applied on the production of drug intermediates. The passage used recombinant Escherichia coil BG20 as the research object, the cytidine biosynthesis pathway was analysized, and optimized the cytidine fermentation conditions according to the path analysis results. The optimization of shaking flask fermentation conditions for cytidine production was carried out by single factor experiments and orthogonal experiment. The optimized fermentation medium was composed of 160 g/L glucose, 13 g/L （NH4）2SO4, 2.2 g/L KH2PO4. The optimized fermentation conditions was initial pH of the medium 7.2, culture temperature 38 ℃, table speed 180 r/min. Under the optimized conditions, cell cytidine production reached 0.2835 g/L, 61.4% higher than the initial conditions.