Metabolic engineering of Klebsiella pneumoniae for the de novo production of 2-butanol as a potential biofuel.
Butanol isomers are important bulk chemicals and promising fuel substitutes. The inevitable toxicity of n-butanol and isobutanol to microbial cells hinders their final titers. In this study, we attempt to engineer Klebsiella pneumoniae for the de novo production of 2-butanol, another butanol isomer which shows lower toxicity than n-butanol and isobutanol. 2-Butanol synthesis was realized by the extension of the native meso-2,3-butanediol synthesis pathway with the introduction of diol dehydratase and secondary alcohol dehydrogenase. By the screening of different secondary alcohol dehydrogenases and diol dehydratases, 320mg/L of 2-butanol was produced by the best engineered K. pneumoniae. The production was increased to 720mg/L by knocking out the ldhA gene and appropriate addition of coenzyme B12. Further improvement of 2-butanol to 1030mg/L was achieved by protein engineering of diol dehydratase. This work lays the basis for the metabolic engineering of microorganism for the production of 2-butanol as potential biofuel.
Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Tsinghua Innovation Center in Dongguan, Dongguan 523808, China. Electronic address: zhenchen2013@mail.tsinghua.edu.cn.
Zhen
Z
Chen
Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
Yao
Y
Wu
Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
Jinhai
J
Huang
Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Tsinghua Innovation Center in Dongguan, Dongguan 523808, China.
Dehua
D
Liu
D020001:1-Butanol / Q000378:metabolism; D000429:Alcohol Oxidoreductases; D056804:Biofuels; D053898:Biosynthetic Pathways; D000440:Butanols / Q000378:metabolism*; D002072:Butylene Glycols; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D055785:Gene Knockdown Techniques; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000378:metabolism*; D060847:Metabolic Engineering; D015202:Protein Engineering
D056804:Biofuels; D000440:Butanols; D002072:Butylene Glycols; C043958:2-butanol; C026978:2,3-butylene glycol; C040507:isobutyl alcohol; D020001:1-Butanol; D000429:Alcohol Oxidoreductases; C025192:isopropanol dehydrogenase (NADP)
2-Butanol; Biofuel; Klebsiella pneumoniae; Metabolic engineering