Acetobacter aceti bacteria are a widespread group of gram-negative, obligate aerobic rods which oxidize ethanol (alcohol) into ethanoic (acetic) acid. They occur mainly in sugary, acidic and/or alcoholic habitats and they play a positive, neutral, or detrimental role in foods and beverages. They are benign, non-pathogenic microorganisms ubiquitous in the environment, particularly in alcoholic ecological niches such as flowers, fruits, fruit flies, honey bees, and also in water and soil. They are generally found as spoilage organisms in alcoholic beverages. A. aceti has a long history of safe use in the fermentation industry for the production of acetic acid (vinegar) from alcohol. Acetic acid bacteria are classified into the genera Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, and the recently described genus Asaia.