多步代谢工程 Klebsiella oxytoca 为高效的l-素生产提供了多步代谢工程
Weikang Sun1, Qiaoyue Yang1, Shuo Wang1
1State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
Synthetic and systems biotechnology
|February 18, 2026
概括
研究人员设计了Klebsiella oxytoca,以高效地产生l-leucine,这是食品和医疗应用中必不可少的氨基酸. 最优化的菌株实现了创纪录的70.1g/Ll-leucine产量.
科学领域:
- 生物技术是生物技术.
- 代谢工程是代谢工程.
- 微生物生产 微生物生产
背景情况:
- 氨酸是一种重要的氨基酸,在食品,料和医疗领域有广泛的应用.
- 目前生产l-氨酸的方法需要优化效率和产量.
- 微生物菌株的代谢工程为增强氨基酸生物合成提供了一个有希望的途径.
研究的目的:
- 为了构建一个高效的l-氨酸生产菌株的Klebsiella oxytoca.
- 通过引入外源生物合成途径和优化基因表达来增强l-leucine的积累.
- 开发一种高产量,无等离子体和诱导剂独立的微生物生产系统,用于l-氨酸.
主要方法:
- 通过引入外源性l-氨酸生物合成途径,改造了Klebsiella oxytoca* VKO-9,一种l-氨酸生产物.
- 修改了l-leucine运输系统,并优化了参与l-leucine合成的关键基因的拷贝数 (例如, *Cg leuA*, *Ec leuCD*, *Ec leuB*, *Nop heDH*).
- 增强了前体供应基因 (*budB*, *Ec ilvD*) 的表达,并引入了来自 *Streptococcus mutans* 的新型耐氧二酸脱水酶.
主要成果:
- 成功构建了*Klebsiella oxytoca* LKO-14的工程菌株.
- 获得了高的l-氨酸标位70.1g/L.
- 获得了0.347g/g的产量和1.46g/L/h的生产率,与以前的方法相比显著改进.
结论:
- 开发的代谢工程策略有效地增强了Klebsiella oxytoca*中的l-leucine生产.
- 由此产生的LKO-14菌株是工业l-氨酸合成的高效和强大的平台.
- 这项工作为大规模,经济高效的l-leucine生产提供了宝贵的基础.
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