To provide a new gene involved in acetic acid resistance of an acetic bacterium, a microorganism containing the gene, especially a method for improving the acetic acid resistance of the acetic bacterium and further to provide a method for efficiently producing a vinegar at a higher acetic acid concentration by using the acetic bacterium having the improved acetic acid resistance.

The new gene having functions to improve the acetic acid resistance at a practical level is cloned from a from a practical acetic bacterium belonging to the genus Gluconacetobacter according to a method for obtaining a gene even in a culture medium at an acetic acid concentration in which proliferation cannot usually be carried out from a chromosomal DNA library of the acetic bacterium. In a transformant in which the gene is transduced into the acetic bacterium, the acetic acid resistance is remarkably improved. When the transformant is cultured in the presence of ethanol, the final ultimate acetic acid concentration can remarkably be improved.