title: Preparation of D-gulose from disaccharide lactitol using microbial and chemical methods.
abstract: When an M31 strain of Agrobacterium tumefaciens was grown in a mineral salt medium at 30 °C containing 1.0% lactitol as sole carbon source, a keto-sugar was efficiently accumulated in the supernatant. This oxidation from lactitol to the keto-sugar was caused by M31 cells grown with medium containing a disaccharide unit, including sucrose, lactitol, lactose, maltose, or maltitol, suggesting that the enzyme is inducible. M31 also demonstrated good growth characteristics in Tryptic Soy Broth (TSB) medium containing 1.0% sucrose, and cells grown under these conditions showed strong lactitol transformation activity. The keto-sugar product was reduced by chemical hydrogenation and the resulting product was hydrolyzed to D-gulose, D-galactose, and D-sorbitol by acid hydrolysis, revealing that the reduced products are lactitol and D-gulosyl-(β-1,4)-D-sorbitol. Taken together, these results indicate that M31 can convert lactitol to 3-ketolactitol and thus provide access to the rare sugar D-gulose.
authors: Rare Sugar Research Center, Kagawa University, Kagawa, Japan. morimoto@ag.kagawa-u.ac.jp
authors: Kenji
authors: K
authors: Morimoto
authors: Tsuyoshi
authors: T
authors: Shimonishi
authors: Seiki
authors: S
authors: Miyake
authors: Goro
authors: G
authors: Takata
authors: Ken
authors: K
authors: Izumori
mesh_terms: D016960:Agrobacterium tumefaciens / Q000378:metabolism*; D001711:Biotransformation; D002364:Caseins; D003470:Culture Media; D005690:Galactose / Q000378:metabolism; D006601:Hexoses / Q000096:biosynthesis*; D006863:Hydrogen-Ion Concentration; D006865:Hydrogenation; D006868:Hydrolysis; D007785:Lactose / Q000378:metabolism; D008320:Maltose / Q000031:analogs & derivatives / Q000378:metabolism; D010084:Oxidation-Reduction; D011492:Protein Hydrolysates; D013012:Sorbitol / Q000031:analogs & derivatives / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D013402:Sugar Alcohols / Q000378:metabolism*
chemical_list: D002364:Caseins; D003470:Culture Media; D006601:Hexoses; D011492:Protein Hydrolysates; D013402:Sugar Alcohols; C026375:trypticase-soy broth; C057406:gulose; D013012:Sorbitol; D013395:Sucrose; D008320:Maltose; C010745:maltitol; D007785:Lactose; C014635:lactitol; D005690:Galactose