Engineering stress tolerance of Escherichia coli by stress-induced-mutagenesis (SIM) based adaptive evolution.

TitleEngineering stress tolerance of Escherichia coli by stress-induced-mutagenesis (SIM) based adaptive evolution.
Publication TypeJournal Article
Year of Publication2013
AuthorsZhu L, Cai Z, Zhang Y, Li Y
JournalBiotechnology journal
Date Published2013 Sep 19
Abstract

Microbial tolerance to toxic products and biomass hydrolysates becomes a challenge for 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 by using Escherichia coli FC40 as a model strain, which was used to quantitatively evaluate the SIM rate. The SIM rate under stressful conditions increased by 92- and 57-fold, respectively, by deleting the mutL or mutS genes to disturb the mismatch repair activity of the host cells. 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-deleting mutant. Using such a method, 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.

DOI10.1242/bio.20135983
Alternate JournalBiotechnol J