title: Enantioselective resolution of γ-lactam by a whole cell of Microbacterium hydrocarbonoxydans (L29-9) immobilized in polymer of PVA-alginate-boric acid.
abstract: Using immobilized cells of a novel strain of Microbacterium hydrocarbonoxydans L29-9 in polymers of polyvinyl alcohol (PVA)-alginate-boric acid, enantioselective resolution of racemic γ-lactam to produce (-)γ-lactam was successfully carried out. A 6:1 ratio of PVA:sodium alginate not only prevented agglomeration of the matrix but also produced beads with high gel strength. The optimum biotransformation conditions were 1 g/L substrate, pH 7.0, reaction temperature of 30 °C, and reaction time of 3 h. After every two cycles, the immobilized cell beads were separated and immersed in 0.5 mM KCl solution at 4 °C for preservation. At optimum conditions, the enantiomeric excess and the yield of (-)γ-lactam were >99% and 34%, respectively. The beads showed a slight decrease in the enantiomeric excess when re-used up to 14 cycles (the enantioselectivity of the immobilized cells decreased slightly after 14 cycles of usage).
authors.affiliation: State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing, China.
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Qin
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wang
authors.forename: Guojun
authors.initials: G
authors.lastname: Zheng
mesh_terms: D000192:Actinomycetales / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D000464:Alginates / Q000737:chemistry*; D055162:Biocatalysis; D001888:Boric Acids / Q000737:chemistry*; D018914:Cells, Immobilized / Q000378:metabolism; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents / Q000494:pharmacology; D007769:Lactams / Q000737:chemistry* / Q000378:metabolism*; D008670:Metals / Q000494:pharmacology; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000464:Alginates; D001888:Boric Acids; D006603:Hexuronic Acids; D007202:Indicators and Reagents; D007769:Lactams; D008670:Metals; D020723:Glucuronic Acid; D011142:Polyvinyl Alcohol; C032688:boric acid