ABSTRACT
Acetic acid bacteria are Gram-negative, rod-shaped, and obligate aerobes and commonly known as vinegar-producing microorganisms. The acetic acid bacteria in general have an ability to oxidize ethanol to acetic acid and glucose to gluconic acid and are classified in the family Acetobacteraceae M. Gillis and J. De Ley 1980. The members of the family are separated into two groups, i.e., the acetous and the acidophilic groups. The acetic acid bacteria are included in the former group. The genus Acetobacter, the type genus of the family Acetobacteraceae was introduced by M. W. Beijerinck, with Acetobacter aceti Beijerinck 1898, the type species of the genus. M. Asai reported two types of intermediate strains, in addition to the strains of the genera Acetobacter and Gluconobacter. In the genus Gluconacetobacter, there were two subclusters or the two subgroups, i.e., the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group.
