Modular pathway engineering for the microbial production of branched-chain fatty alcohols

Biotechnology for Biofuels

Fuzhong Zhang¹  Di Liu¹  James B. Qiao¹  Wen Jiang¹  Gayle J. Bentley² 

[1] Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis;Division of Biological & Biomedical Sciences, Washington University in St. Louis;

关键词: Branched long-chain fatty alcohols;    Branched-chain fatty acids;    Advanced biofuels;    Modular pathway engineering;   

DOI  :  10.1186/s13068-017-0936-4

来源: DOAJ

【 摘 要 】

Abstract The intrinsic structural properties of branched long-chain fatty alcohols (BLFLs) in the range of C12 to C18 make them more suitable as diesel fuel replacements and for other industrial applications than their straight-chain counterparts. While microbial production of straight long-chain fatty alcohols has been achieved, biosynthesis of BLFLs has never been reported. In this work, we engineered four different biosynthetic pathways in Escherichia coli to produce BLFLs. We then employed a modular engineering approach to optimize the supply of α-keto acid precursors and produced either odd-chain or even-chain BLFLs with high selectivity, reaching 70 and 75% of total fatty alcohols, respectively. The acyl-ACP and alcohol-producing modules were also extensively optimized to balance enzyme expression level and ratio, resulting in a 6.5-fold improvement in BLFL titers. The best performing strain overexpressed 14 genes from 6 engineered operons and produced 350 mg/L of BLFLs in fed-batch fermenter. The modular engineering strategy successfully facilitated microbial production of BLFLs and allowed us to quickly optimize new BLFL pathway with high titers and product specificity. More generally, this work provides pathways and knowledge for the production of BLFLs and BLFL-related, industry-relevant chemicals in high titers and yields.

【 授权许可】

Unknown