To elucidate a protein for reinforcing acetic acid resistance at a genetic level, to obtain a microorganism having high acetic acid resistance and capable of producing acetic acid in a high concentration, and to provide a method for efficiently producing vinegar having a high acetic acid concentration with the microorganism.

The protein ACCC1. A gene DNA encoding the protein ACCC1. A microorganism in whose cell the copy number of the DNA is amplified and which has high acetic acid resistance. A method for producing a vinegar is characterized by culturing an alcohol-oxidizing ability-having microorganism among the above-microorganisms in an alcohol-containing culture medium to produce and accumulate the acetic acid in the culture medium.