Abstract: A novel species of acetic acid bacteria belonging to the genus of Acetobacter, to which a scientific name of Acetobacter altoacetigenes MH-24 (FERM BP-491) is given. The bacteria can grow in a culture medium containing at least 4 w/v % of acetic acid with a pH of 3.5 at the highest. Pure samples of species have been isolated and used for the fermentation production of vinegar without undertaking the conventional inoculation process using the prior art seed vinegar to provide a high-quality vinegar of high acetic acid concentration such as white vinegar, with high production efficiency.

Abstract: Novel highly viscous acidic heterpolysaccharide AM-2 is produced from a strain of genus Acetobacter isolated from vinegar mash, and is useful as an adhesive, coating agent, drilling mud additive, enhanced oil recovering agent, etc., as well as a material useful for the production of foods, drugs and cosmetics because of its safety and high viscosity.

Abstract: Novel highly viscous polysaccharides composed mainly of (a) glucose, (b) galactose, (c) mannose, and (d) glucuronic acid, the molar ratio of (a):(b):(c):(d) being 10:3-6:0.5-2:0.5-2 (preferably 10:3-4:1-2:1-2). The invention also provides the process for producing the highly viscous polysaccharides which comprises cultivating a highly viscous polysaccharide-producing microorganism which is an acetic acid bacteria in a nutrient medium until a substantial amount of polysaccharides has accumulated in the nutrient medium, and recovering the accumulated polysaccharides from the nutrient medium.