Increase of organic solvent tolerance by overexpression of manXYZ in Escherichia coli

Transcriptional analysis has been investigated to detect the genes involved in organic solvent tolerance. A time course of gene expression profiles of Escherichia coli after exposure to organic solvents revealed that the expression levels of manX, manY, and manZ genes were strongly upregulated by 13.2-, 10.0-, and 7.0-folds, respectively, after 2 min and then decreased after 10 min. Organic solvent tolerance of E. coli was investigated by inducing overexpression of manX, manY, and manZ genes and manXYZ operon that encode a sugar transporter of the phosphotransferase system. Although the expression of manX, manY, and manZ alone was not effective, the organic solvent tolerance level was increased by the expression of manXYZ. The intracellular hexane level was kept lower in E. coli cells overexpressing manXYZ after 4 h of incubation with hexane.