acetobacterPronunciation: /əˌsiːtə(ʊ)ˈbaktə, ˌasɪtəʊ-/Definition of acetobacter noun [mass noun] bacteria that oxidize organic compounds to acetic acid, as in vinegar formation. Genus Acetobacter; Gram-negative oval or rod-shaped bacteria Origin:modern Latin (genus name), from aceto- + bacteriumacetobacter in other Oxford dictionaries Definition of acetobacter in the US English dictionary