工程大肠杆菌以同化β-氨酸作为主要的碳来源
Nga Yu Poon1, Anthony J Sinskey2, Kang Zhou3
1Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore.
Applied microbiology and biotechnology
|May 30, 2023
概括
研究人员设计了大肠杆菌以代谢β-氨酸,这是塑料衍生的1,3-propanediol (1,3-PDO) 的替代品. 这为塑料废弃物通过通过酸半化物 (MSA) 将β-alanine转化为乙-CoA建立了上循环的途径.
科学领域:
- 代谢工程是代谢工程.
- 合成生物学 合成生物学
- 生物技术是生物技术.
- 塑料废物再循环利用 塑料废物再循环利用
背景情况:
- 全球塑料废物积累需要可持续的解决方案,包括塑料衍生的单体的生物上循环.
- 来自1,3-propanediol (1,3-PDO) 的聚合物具有重要意义,但对于将1,3-PDO同化为中央碳代谢的代谢途径并不存在.
- 马洛半化物 (MSA) 被提议作为1,3-PDO同化的主要中间体,但MSA是一种有毒的化物.
研究的目的:
- 在大肠杆菌中设计一种代谢途径,以将MSA的替代物β-alanine作为主要的碳来源进行同化.
- 通过MSA中间体识别和实施能够通过MSA中间体将β-alanine转化为乙-CoA的酶.
- 为从塑料废弃物中获得的1,3-PDO生物同化和回收利用建立基础途径.
主要方法:
- 改造E. coli MG1655以表达来自Pseudomonas aeruginosa的β-alanine/pyruvate转氨酶 (PaBapt) 以获得β-alanine转化为MSA.
- 从Vibrio natriegens中选,进化并识别了CoA-乙化马隆酸半脱酶 (VnMmsD),以将MSA转化为乙-CoA.
- 通过在单个等离子体上共同表达酶并破坏本地基因 (EcYdfG) 来防止碳损失,优化了该途径.
主要成果:
- 成功设计了能够同化β-氨酸的大肠杆菌BA02,在96小时后达到4.5的光学密度 (OD600).
- 确定了两种VnMmsD,这些VnMmsD完成了从MSA到乙-CoA.的代谢途径.
- 开发了一种优化的菌株,大肠杆菌BA07∆,在24小时内使用5g/Lβ-alanine达到6的OD600,证明了高效的同化.
结论:
- 证明了一种新的代谢途径的可行性,用于大肠杆菌中的β-氨酸同化,为1,3-PDO上循环铺平了道路.
- 这些工程菌株为未来开发微生物过程提供了一个强大的平台,以将塑料衍生的单体转化为有价值的产品.
- 该研究强调了合成生物学方法的潜力,通过生物解决方案解决塑料废物挑战.
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