Acetic acid bacteria are currently accommodated in the acetous group, the family Acetobacteraceae, the class Alphaproteobacteria, based on phylogeny, physiology, and ecology. The acetic acid bacteria are classified at present in 17 genera, of which many species have been reported in the genera Acetobacter, Gluconobacter, Gluconacetobacter, Asaia, and Komagataeibacter. Of the remaining 12 genera, Acidomonas, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Endobacter, Nguyenibacter, and Swingsia are monotypic; the genus Neokomagataea contains two species. In the class Gammaproteobacteria, the genus Frateuria has been mentioned taxonomically as pseudacetic acid bacteria. In addition, isolation and identification of acetic acid bacteria are described.