Journal Article

Engineering Clostridium acetobutylicum with a histidine kinase knockout for enhanced n-butanol tolerance and production

Yang, Shang-Tian, Xue, Chuang, Xu, Mengmeng, Zhao, Jingbo, Yu, Le, Tang, I-Ching

2015

Overview

Clostridium acetobutylicum JB200, a mutant strain of C. acetobutylicum ATCC 55025 obtained through strain evolution in a fibrous bed bioreactor, had high butanol tolerance and produced up to ~21 g/L butanol from glucose in batch fermentation, an improvement of ~67 % over the parental strain (~12.6 g/L). Comparative genomic analysis revealed a single-base deletion in the cac3319 gene leading to C-terminal truncation in its encoding histidine kinase (HK) in JB200. To study the effects of cac3319 mutation on cell growth and fermentation, the cac3319 gene in ATCC 55025 was disrupted using the ClosTron group II intron-based gene inactivation system. Compared to ATCC 55025, the cac3319 HK knockout mutant, HKKO, produced 44.4 % more butanol (18.2 ± 1.3 vs. 12.6 ± 0.2 g/L) with a 90 % higher productivity (0.38 ± 0.03 vs. 0.20 ± 0.02 g/L h) due to increased butanol tolerance, confirming, for the first time, that cac3319 plays an important role in regulating solvent production and tolerance in C. acetobutylicum. This work also provides a novel metabolic engineering strategy for generating high-butanol-tolerant and high-butanol-producing strains for industrial applications.

• Publisher: Springer-Verlag,Springer Berlin Heidelberg,Springer,Springer Nature B.V
• Subject: 1-Butanol - metabolism / Adaptation / batch fermentation / Bioenergy and Biofuels / Biomedical and Life Sciences / Bioreactors / Biotechnology / Butanol / cell growth / Cloning, Molecular / Clostridium / Clostridium acetobutylicum / Clostridium acetobutylicum - genetics / Clostridium acetobutylicum - metabolism / Crude oil prices / Culture Media / DNA sequencing / DNA, Bacterial - genetics / E coli / Engineering / evolution / Fermentation / Genes / Genetic aspects / Genomes / genomics / Glucose / Glucose - metabolism / Histidine / Histidine Kinase / Inactivation / industrial applications / Industrial Microbiology / Kinases / Life Sciences / metabolic engineering / Metabolic Engineering - methods / Metabolism / Methods / Microbial Genetics and Genomics / Microbiology / Mutagenesis / mutants / Mutation / Phosphotransferases / Physiological aspects / Plasmids / Plasmids - genetics / Production processes / Productivity / Properties / Protein Kinases - metabolism / Proteins / Sequence Analysis, DNA / Signal transduction / Solvents / Solvents - chemistry / Studies