温度对大肠杆菌L-色氨酸发酵过程的影响

Effect of Temperature on the Process of Escherichia coli L-Tryptophan Fermentation

目的:研究变温控制对大肠杆菌TRTHL-色氨酸补料分批发酵过程中生物量、色氨酸产量、比生长速率及质粒稳定性的影响。方法:利用5L自控发酵罐对L-色氨酸补料分批发酵过程进行温度控制,对不同温度下相关参数进行分析比较,确定优化的温度控制方案。结果:以30～36℃顺序升温的工艺进行发酵得到理想结果,与单一温度控制策略相比,L-色氨酸产量提高了15.4%;色氨酸的比合成速率提高了21.6%;质粒稳定性增加,未出现质粒丢失现象,质粒拷贝数保持在恒定水平。结论:温度对大肠杆菌L-色氨酸发酵有重要影响。

Objective： To study the effect of variable temperature on biomass, L-tryptophan yield, the growth rate and the stability of the plasmid in the pmcess of Escherichia coli TRTH L-tryptophan fed-batch fermentation. Methods： 5L-controlled fermentator was used in temperature control in the process of L-tryptophan fed-batch fermentation, to analyses different temperature-related parameters and determine the optimal temperature control strategy. Results： Under the optimized fermentation conditions of 30-36℃ variable temperature control strategy, a final L-tryptophan concentration of 30.19 g/L was obtained after 45 h in 5 liter fermentor, increased by 15.4%; tryptophan synthesis rate increased 21.6%; no loss of plasmid was observed, plasmid copy number remained at a constant level. Conclusion： The temperature is an important impact on the L-tryptophan production.