Abstract: Arthrobacter simplex，a strain with steroid C1，2 dehydrogenation ability，has been widely used in the steroid industry，usually adding ethanol in the transforming system may catalyze the dissolution of hydrophobic substrates. Our prior work by LC-MS/MS and bioinformatics analysis found that heat shock protein（HSP）GroEL was closely correlated to the cell adaptive behavior under ethanol stress condition. Based on this concept，groEL gene was cloned by PCR while using A. simplex TCCC 11037 genome as a template. The results showed that the homologies of nucleotide and amino acid sequence of GroEL in the strain were the highest with that from Nocardioides sp. JS614 by the ratio of 89% and 95%，respectively. Then its heterologous expression was conducted in Escherichia coli BL21（DE3）with the vector pET-22b（+），and the results showed that the recombinant strain presented the significant increase on the survival performance under the shock condition with high-concentration of methanol，hypertonicity and superacid，as well as the growth performance under the proper stresses of them. The study was the first report on the cloning and expression of gene groEL from A. simplex，and also provided fundamental data for exploring the biological function of HSP protein GroEL from A. simplex.

Key words: Arthrobacter simplex, groEL, heterologous expression, Escherichia coli, resistance performance