Effects of sodium pyruvate on the biosynthesis of polysialic acid by E. coli CCTCC M208088 were investigated . The results showed that the addition of sodium pyruvate enhanced the production of polysialic acid , and the optimum time and concentration for sodium pyruvate addition were 0h and 6g/L . At the end of fermentation, the polysialic acid production reached 3 .47 g/L , increased by 73％ as compared with the control , and the conversion rate increased by 125％. The final polysialic acid production was as high as 6 .6g/L in a 30 L reactor , increased by 53 .5％ as compared with the control. The main role of sodium pyruvate was to enhance TCA cycle of the bacteria in vivo and probably improved the level of intracellular energy charge , which would stimulate polysialic acid synthesis .%研究了丙酮酸钠对E.coli CCTCC M208088发酵生产聚唾液酸的影响.首先在摇瓶水平上优化了丙酮酸钠的添加策略:发酵初始培养基中添加6g/L丙酮酸钠,聚唾液酸的产量达到最高水平3.47g/L,相比空白相比提高了73%,聚唾液酸产率(YP/(X·S))提高了125%.在30L发酵罐中,添加丙酮酸钠使聚唾液酸产量达到了6.6g/L,相对照提高了53.5%.通过有机酸分析,添加丙酮酸钠增强了菌体内三羧酸循环,可能导致胞内能荷水平的提高,从而促进了聚唾液酸的合成.
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