Enhancing ethanol tolerance of Escherichia coli to improve the efficiency of recombinant protein expression

Abstract

    Escherichia coli is one of the most common hosts to produce recombinant proteins due to its short culturing time and high biomass yield. However, the traditional strains often lack the resistance against chemical inhibitors or environmental stresses which impact on cell division and lessen the effectiveness of target protein expression. In this study, the E. coli strains with direct ethanol tolerance was developed to promote the cellular alterations associated with the enhancement of DNA synthesis and the improvement of the production of recombinant proteins. The result showed that the E. coli BL21(DE3) and E. coli C41(DE3) have been improved in ethanol tolerance (7-8) % by applying laboratory adaptive evolution in Luria Bertani medium and M9 minimal medium. Additionally, the protein expression efficiency has been significantly increased when using them as a host for PETase protein expression compared to the original strains. The evolution of E. coli with high ethanol tolerance might be a potential factor contributing to the development of an effective expression system for recombinant protein production.