To elucidate at genetic level a protein enhancing acetic acid resistance, to obtain microorganisms having high acetic acid resistance and capable of efficiently producing acetic acid in high concentrations, and to provide a method for efficiently producing a vinegar rich in acetic acid using the microorganisms.

The protein SCDH2(short-chain dehydrogenase/reductase-2) is provided. A DNA for a gene encoding the protein SCDH2 is provided. The microorganisms having high acetic acid resistance are obtained by amplifying the copy number of the DNA in the microorganismal cells. The method for producing the vinegar comprises culturing in an alcohol-containing medium microorganisms having the ability to oxidize alcohol among the above-microorganisms and producing and accumulating acetic acid in the medium.