title: Involvement of Acetobacter orientalis in the production of lactobionic acid in Caucasian yogurt ("Caspian Sea yogurt") in Japan.
abstract: Lactobionic acid was first found in a Caucasian fermented milk product popularly known as "Caspian Sea yogurt" in Japan. The presence of lactobionic acid in the fermented milk was indicated by the results of both high-performance anion-exchange chromatographic analysis with pulsed amperometric detection and mass spectrometric analysis. Thereafter, the acid was purified from the yogurt and analyzed by nuclear magnetic resonance. A substantial amount of lactobionic acid was found to be accumulated in the upper layer of the yogurt, especially within 10 mm from the surface. A total of 45 mg of lactobionic acid per 100 g of the upper yogurt layer was collected after 4 d of fermentation. The annual intake of lactobionic acid in individuals consuming 100 g of the yogurt every day would be 0.5 to 1.0 g. A lactose-oxidizing bacterium was isolated from the fermented milk and was identified as Acetobacter orientalis. Washed A. orientalis cells oxidized monosaccharides such as d-glucose at considerable rates, although their activities for substrates such as lactose, maltose, and cellobiose were much lower. When A. orientalis cells were cultivated in cow's milk, they exhibited lactose-oxidizing activity, suggesting that this bacterium was the main organism involved in the production of lactobionic acid in the yogurt.
authors.affiliation: Osaka Municipal Technical Research Institute, 6-50, Morinomiya 1-chome, Joto-ku, Osaka 536-8553, Japan. kiryu@omtri.city.osaka.jp
authors.forename: T
authors.initials: T
authors.lastname: Kiryu
authors.forename: T
authors.initials: T
authors.lastname: Kiso
authors.forename: H
authors.initials: H
authors.lastname: Nakano
authors.forename: K
authors.initials: K
authors.lastname: Ooe
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: H
authors.initials: H
authors.lastname: Murakami
mesh_terms: D000091:Acetobacter / Q000302:isolation & purification / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D004187:Disaccharides / Q000032:analysis / Q000378:metabolism*; D005516:Food Microbiology; D007564:Japan; D010084:Oxidation-Reduction; D013997:Time Factors; D015014:Yogurt / Q000032:analysis / Q000382:microbiology*
chemical_list: D004187:Disaccharides; C005608:lactobionic acid