ABSTRACT
Acetic acid bacteria (AAB) are a group of Alphaproteobacteria belonging to the family Acetobacteraceae. They are frequent colonizers of tropical flowers and fruits, and food fermenters. The food industry is interested in them because of their ability to produce large amounts of acetic acid from ethanol during vinegar production, kombucha tea, or cocoa bean fermentation. They are also used for the production of specific chemicals, such as ascorbic acid and bacterial cellulose. Acetobacter species are important in biotechnological processes because they can oxidize ethanol to acetic acid. Acetobacter species use an alternative tricarboxylic acid cycle, which enables the removal of the cytosolic acetate, via acetyl-CoA oxidation, as carbon dioxide. Genomes of AAB contain many genes coding for the proteins previously implicated in acid stress response in Escherichia coli. The genus includes important vinegar producers, such as Acetobacter pasteurianus, A. aceti and A. pomorum. The other emerging pathogen is Granulibacter bethesdensis.
