Acetobacterium is a genus of anaerobic, gram-positive bacteria that belong to the Eubacteriaceae family. The name has originated from the fact that they are acetogens, predominantly making acetic acid as a by-product of anaerobic metabolism. Most of the species reported in this genus are homoacetogens, i.e. solely producing acetic acid as their metabolic by-product. They should not be confused with acetic acid bacteria which are aerobic, gram-negative alphaproteobacteria and widely used to produce vinegar.