Ethanol is generally toxic to microorganisms, and intracellular and extracellular accumulation of ethanol inhibits cell growth and metabolism. In this study, pyruvate decarboxylase (pdc) and alcohol dehydrogenase (adhB) were cloned into pET-32a vector and then introduced into E. coli BL21 to produce ethanol. Heat shock genes (BEM1 and SOD2) from Saccharomyces cerevisiae were inserted into recombinant ethanolic E. coli using pET28-a vector to improve ethanol shock resistance. Three different strains were constructed: Ethanolic E. coli (adhB and pdc genes inserted using pET32-a vector), BEM1 gene-inserted E. coli (BEM1 inserted using pET-28a), and SOD2-inserted E. coli (SOD2 inserted using pET28-a). Construction of these three different strains allowed comparison of the functions of these heat shock genes as well as their roles in ethanol tolerance. The toxicity of ethanol in recombinant ethanolic E. coli was tested by measuring cell growth in response to various ethanol concentrations. The results show that SOD2-inserted E. coli showed higher ethanol resistance than ethanolic E. coli.
- Escherichia coli
- Saccharomyces cerevisiae
- ethanol resistance
- heat shock genes (SOD2, BEM1)
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology
- Biomedical Engineering