Premium
Engineering stress tolerance of Escherichia coli by stress‐induced mutagenesis (SIM)‐based adaptive evolution
Author(s) -
Zhu Linjiang,
Cai Zhen,
Zhang Yanping,
Li Yin
Publication year - 2014
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.201300277
Subject(s) - escherichia coli , mutagenesis , mutant , strain (injury) , biology , gene , chemistry , computational biology , biochemistry , anatomy
Microbial tolerance to toxic products and biomass hydrolysates is a challenge for the production of fuels and chemicals from renewable resources. To improve cellular tolerance to these environmental stresses, a novel adaptive evolutionary strategy based on stress‐induced mutagenesis (SIM) was developed using non‐dividing cells. The concept of this method was proved using Escherichia coli FC40 as a model strain, which was used to quantitatively evaluate the rate of SIM. By deleting either the mutL or mutS gene to disturb the mismatch repair activity of the host cells, the SIM rate under stressful conditions increased by 92‐ and 57‐fold, respectively. A periodic SIM‐based adaptive evolution procedure, which synchronized the mutagenesis and the selection process in a single plate‐incubation step, was then developed using the mutL ‐deleted mutant. E. coli mutants tolerant to high concentrations of butanol (13 g/L), NaCl (95 g/L), and high temperature (50°C) were obtained. These results indicate that stress‐induced adaptive evolution in non‐dividing cells is an effective approach that can improve microbial tolerance against various stresses and generate robust microbial strains suitable for production of fuels and chemicals.