To provide a new gene participating in the acetic acid resistance of an acetic acid bacterium, to provide a microorganism using the gene, to provide a method for especially improving the acetic acid resistance of the acetic acid bacterium, and to provide a method for producing a vinegar, by which the vinegar having a high acetic acid resistance can efficiently be produced with an acetic acid bacterium having improved acetic acid resistance.

A new gene capable of improving acetic acid resistance at a practical level is screened from a practical acetic acid bacterium belonging to Gluconacetobacter by a method for obtaining a gene capable of being proliferated even in a culture medium having an acetic acid concentration usually not permitting the proliferation from the chromosome DNA library of the acetic acid bacteria.