Biotechnology Bulletin ›› 2017, Vol. 33 ›› Issue (9): 101-109.doi: 10.13560/j.cnki.biotech.bull.1985.2017-0369

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Enhanced Methanol Utilization in Genetically Engineered Escherichia coli by Directed Evolution

WANG Xiao-lu1,2,3,WANG Yu2,3,LIU Jiao2,3,ZHENG Ping2,3,LU Fu-ping1   

  1. 1. School of Biological Engineering,Tianjin University of Science and Technology,Tianjin 300457;
    2. Key Laboratory of Systems Microbial Biotechnology,Chinese Academy of Sciences,Tianjin 300308;
    3. Tianjin Institute of Industrial Biotechnology,Chinese Academy of Sciences,Tianjin 300308
  • Received:2017-05-08 Online:2017-09-01 Published:2017-09-15

Abstract: Methanol is an important organic chemical raw material as well as an attractive alternative of sugar for biochemical industry because of its cost advantage and higher degree of carbon reduction. However,commonly used industrial microorganisms such as Escherichia coli cannot utilize methanol as a carbon source,which has become a bottleneck for the application of methanol in bio-production processes. In this study,a methanol utilization pathway(ribulose monophosphate pathway)was constructed in E. coli using an engineering genetically engineered E. coli as a starting strain,the random mutation occurred by continuous passage and direct evolution. Then the mutants were screened using methanol as the carbon source,and 2 mutants that grew well on methanol were obtained. When methanol used as an accessory carbon source,biomass of the mutant 25113ΔfrmA/pZWM1-13 increased by 27.6% compared to the starting strain 25113ΔfrmA/pZWM1. 13C labeling of proteinogenic amino acids detection showed that 13C labeled amino acids increased obviously in the mutant 25113ΔfrmA/pZWM1-13. Among them,13C labeled methionine increased by 7.236%. Therefore,directed evolution improved methanol utilization efficiency of the genetically engineered E. coli.

Key words: methanol, ribulose monophosphate pathway, Escherichia coli, directed evolution