Title Improved tolerance of Escherichia coli to oxidative stress by expressing putative response regulator homologs from Antarctic bacteria
Author Seo-jeong Park1, Sangyong Lim2, and Jong-il Choi1*
Address 1Department of Biotechnology and Bioengineering, Interdisciplinary Program for Bioenergy and Biomaterials, Chonnam National University, Gwangju 61186, Republic of Korea, 2Biotechnology Research Division, Korea Atomic Energy Research Institute, Jeongeup 56212, Republic of Korea
Bibliography Journal of Microbiology, 58(2),131-141, 2020,
DOI 10.1007/s12275-020-9290-5
Key Words response regulator homologs, oxidative stress, tolerance, resistance, Antarctic bacterium
Abstract Response regulator (RR) is known a protein that mediates cell’s response to environmental changes. The effect of RR from extremophiles was still under investigation. In this study, response regulator homologs were mined from NGS data of Antarctic bacteria and overexpressed in Escherichia coli. Sixteen amino acid sequences were annotated corresponding to response regulators related to the two-component regulatory systems; of these, 3 amino acid sequences (DRH632, DRH1601 and DRH577) with high homology were selected. These genes were cloned in pRadGro and expressed in E. coli. The transformant strains were subjected to various abiotic stresses including oxidative, osmotic, thermal stress, and acidic stress. There was found that the robustness of E. coli to abiotic stress was increased in the presence of these response regulator homologs. Especially, recombinant E. coli overexpressing drh632 had the highest survival rate in oxidative, hypothermic, osmotic, and acidic conditions. Recombinant E. coli overexpressing drh1601 showed the highest tolerance level to osmotic stress. These results will be applicable for development of recombinant strains with high tolerance to abiotic stress.