Optimization of n-butanol synthesis in Lactobacillus brevis via the functional expression of thl, hbd, crt and ter. (1st December 2020)

• Record Type: Journal Article
• Authors: Li, Qi; Wu, Meixian; Wen, Zhiqiang; Jiang, Yuan; Wang, Xin; Zhao, Yawei; Liu, Jinle; Yang, Junjie; Jiang, Yu; Yang, Sheng
• Is Part Of: Journal of industrial microbiology & biotechnology. Volume 47:Number 12(2020)
• Page Start: 1099
• Page End: 1108
• Publication Date: 2020-12-01
• Subjects: Lactic acid bacteria -- Lactobacillus brevis -- Clostridium -- Butanol -- Tolerance; Industrial microbiology -- Periodicals; 660.62
• DOI: 10.1007/s10295-020-02331-2
• Languages: English
• ISSNs: 1367-5435

Abstract

Abstract : Abstract: N -butanol is an important chemical and can be naturally synthesized by Clostridium species; however, the poor n-butanol tolerance of Clostridium impedes the further improvement in titer. In this study, Lactobacillus brevis, which possesses a higher butanol tolerance, was selected as host for heterologous butanol production. The Clostridium acetobutylicum genes thl, hbd, and crt which encode thiolase, β-hydroxybutyryl-CoA dehydrogenase, and crotonase, and the Treponema denticola gene ter, which encodes trans -enoyl-CoA reductase were cloned into a single plasmid to express the butanol synthesis pathway in L. brevis . A titer of 40 mg/L n -butanol was initially achieved with plasmid pLY15-opt, in which all pathway genes are codon-optimized. A titer of 450 mg/L of n-butanol was then synthesized when ter was further overexpressed in this pathway . The role of metabolic flux was reinforced with pLY15, in which only the ter gene was codon-optimized, which greatly increased the n-butanol titer to 817 mg/L. Our strategy significantly improved n-butanol synthesis in L. brevis and the final titer is the highest achieved amongst butanol-tolerant lactic acid bacteria. Graphic abstract: