使用系统代谢工程的Klebsiella oxytocaca有效地生产L-氨酸
Menghao Cao1, Weikang Sun1, Shuo Wang1
1State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
Bioresource technology
|January 31, 2024
概括
研究人员对Klebsiella oxytoca进行了高产量L-氨酸生产的工程设计,达到122g/L. 这种代谢工程策略将发酵重定向到有价值的氨基酸合成.
科学领域:
- 代谢工程和合成生物学
- 微生物发酵 微生物发酵
- 生物化学生产 生化生产
背景情况:
- 作为一种必不可少的分支链氨基酸,L-Valine具有多种工业应用.
- 目前的微生物生产方法在产量和效率方面面临挑战.
- 克莱布西拉 (Klebsiella oxytoca) 是一个已知的2,3-butanediol生产者,需要代谢重定向以合成L-瓦林.
研究的目的:
- 为了设计Klebsiella oxytoca,以实现高效的L-氨酸生物合成.
- 将新陈代谢流量从2,3-butanediol转向L-氨酸生产.
- 为了优化高度L-氨酸的发酵条件.
主要方法:
- 在Klebsiella oxytoca中进行代谢流量分析和途径工程.
- 引入外源的L-氨酸生物合成基因.
- 在α-乙酸盐前体处阻断内源的2,3-butanediol通路.
- 增强L-氨酸的流出和pyruvate聚合.
- 构建一个无等离子体的工程菌株 (K. oxytoca VKO-9).
主要成果:
- 工程K. oxytocaVKO-9通过食批发发酵在56小时内产生122g/L的L-氨酸,产量为0.587g/g.
- 重复食批次发酵实现了平均L-氨酸度为81.3g/L,产量为0.599g/g,生产率为3.39g/L/h.
- 代谢重定向成功地将碳流转向L-氨酸合成.
结论:
- 开发的代谢工程策略对于使用Klebsiella oxytoca.高度L-氨酸生产是有效的.
- 优化发酵过程,包括重复食批量,提高生产率,管理产品沉.
- 这种方法为可持续的微生物生产L-氨酸提供了一个有希望的平台.
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