title: Efficient biosynthesis of D-allose from D-psicose by cross-linked recombinant L-rhamnose isomerase: separation of product by ethanol crystallization.
abstract: Mass production of a rare aldohexose D-allose from D-psicose was achieved in a batch reaction by crude recombinant L-rhamnose isomerase (L-RhI) cross-linked with glutaraldehyde. The D-psicose substrate was, in turn, mass produced from a naturally abundant ketohexose D-fructose by immobilized recombinant D-tagatose 3-epimerase (D-TE). At an equilibrium state, 25% of D-psicose was isomerized to D-allose, that is, 25 g of D-allose was obtained from 100 g of D-psicose. The D-allose product was easily separated and crystallized from the reaction mixture that contains 25%D-allose, 8%D-altrose and 67%D-psicose using ethanol. Empirically, approximately 338 g, that is, 90% of a theoretical overall yield for the purification of pure D-allose crystals was produced from 1.5 kg of D-psicose within 30 d using a constructed bioreactor. The cross-linked enzyme had an operative half-life of two months after repeated usages.
authors.affiliation: Department of Biochemistry and Food Science, Faculty of Agriculture and Rare Sugar Research Center, Kagawa University, Miki-cho, Kagawa 761-0795, Japan.
authors.forename: Buetusiwa Thomas
authors.initials: BT
authors.lastname: Menavuvu
authors.forename: Wayoon
authors.initials: W
authors.lastname: Poonperm
authors.forename: Khim
authors.initials: K
authors.lastname: Leang
authors.forename: Naoki
authors.initials: N
authors.lastname: Noguchi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Okada
authors.forename: Kenji
authors.initials: K
authors.lastname: Morimoto
authors.forename: Tom Birger
authors.initials: TB
authors.lastname: Granström
authors.forename: Goro
authors.initials: G
authors.lastname: Takada
authors.forename: Ken
authors.initials: K
authors.lastname: Izumori
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000737:chemistry*; D001709:Biotechnology / Q000379:methods*; D002474:Cell-Free System; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003460:Crystallization; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000378:metabolism; D000431:Ethanol / Q000737:chemistry; D005632:Fructose / Q000096:biosynthesis*; D005947:Glucose / Q000096:biosynthesis*; D005976:Glutaral / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D011994:Recombinant Proteins / Q000737:chemistry*; D012210:Rhamnose / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D011994:Recombinant Proteins; C003243:psicose; D005632:Fructose; D000431:Ethanol; C002055:allose; D019747:Aldose-Ketose Isomerases; C062878:L-rhamnose isomerase; D005947:Glucose; D012210:Rhamnose; D005976:Glutaral