聚羟基丁酸酯
大肠杆菌
醇脱氢酶
乙醇
生物化学
乙醛
生物合成
代谢工程
拉伤
乙醇燃料
化学
脱氢酶
细菌
生物
酶
基因
解剖
遗传学
作者
Liang Hong,Xiaoqiang Ma,Wenbo Ning,Yurou Liu,Anthony J. Sinskey,Gregory Stephanopoulos,Kang Zhou
标识
DOI:10.1016/j.ymben.2020.11.010
摘要
Engineering microbes to utilize non-conventional substrates could create short and efficient pathways to convert substrate into product. In this study, we designed and constructed a two-step heterologous ethanol utilization pathway (EUP) in Escherichia coli by using acetaldehyde dehydrogenase (encoded by ada) from Dickeya zeae and alcohol dehydrogenase (encoded by adh2) from Saccharomyces cerevisiae. This EUP can convert ethanol into acetyl-CoA without ATP consumption, and generate two molecules of NADH per molecule of ethanol. We optimized the expression of these two genes and found that ethanol consumption could be improved by expressing them in a specific order (ada-adh2) with a constitutive promoter (PgyrA). The engineered E. coli strain with EUP consumed approximately 8 g/L of ethanol in 96 h when it was used as sole carbon source. Subsequently, we combined EUP with the biosynthesis of polyhydroxybutyrate (PHB), a biodegradable polymer derived from acetyl-CoA. The engineered E. coli strain carrying EUP and PHB biosynthetic pathway produced 1.1 g/L of PHB from 10 g/L of ethanol and 1 g/L of aspartate family amino acids in 96 h. We also engineered a E. coli strain to produce 24 mg/L of prenol in an ethanol-containing medium, supporting the feasibility of converting ethanol into different classes of acetyl-CoA derived compounds.
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