title: Enantioselective hydrolysis of (R)-2, 2-dimethylcyclopropane carboxamide by immobilized cells of an R-amidase-producing bacterium, Delftia tsuruhatensis CCTCC M 205114, on an alginate capsule carrier.
abstract: Immobilized cells of Delftia tsuruhatensis CCTCC M 205114 harboring R-amidase were applied in asymmetric hydrolysis of (R)-2, 2-dimethylcyclopropane carboxamide (R - 1) from racemic (R, S)-2, 2-dimethylcyclopropane carboxamide to accumulate (S)-2, 2-dimethylcyclopropane carboxamide (S - 1). Maximum R-amidase activity of 13.1 U/g wet cells (0.982 U/g beads) was obtained under conditions of 3% sodium alginate, 2.5% CaCl(2), 15 h crosslinking and 2 mm bead size, which was 53.9% of that of free cells (24.3 U/g wet cells). In addition, characterization of the immobilized cells was examined. The optimum R - 1 hydrolysis conditions were identified as follows: substrate concentration 10 mM, pH 8.5, temperature 35 degrees C and time course 40 min. Under optimum conditions, the maximum yield and enantiomeric excess of (R)-2, 2-dimethylcyclopropanecarboxylic acid were 49.5% and >99%, respectively. This afforded S - 1 with a yield >49% and an e.e. of 97.7%. With good operational stability and excellent enanotioselectivity, the immobilized cells could be potentially utilized in industrial production of S - 1.
authors.affiliation: Institute of Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, People's Republic of China.
authors.forename: Yuan-Shan
authors.initials: YS
authors.lastname: Wang
authors.forename: Ren-Chao
authors.initials: RC
authors.lastname: Zheng
authors.forename: Jian-Miao
authors.initials: JM
authors.lastname: Xu
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Cheng
authors.forename: Zhi-Hua
authors.initials: ZH
authors.lastname: Feng
authors.forename: Li-Ling
authors.initials: LL
authors.lastname: Liu
authors.forename: Yu-Guo
authors.initials: YG
authors.lastname: Zheng
authors.forename: Yin-Chu
authors.initials: YC
authors.lastname: Shen
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000581:Amidohydrolases / Q000378:metabolism*; D018914:Cells, Immobilized; D003521:Cyclopropanes / Q000378:metabolism*; D042742:Delftia / Q000201:enzymology* / Q000378:metabolism; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007218:Industrial Microbiology; D007700:Kinetics; D012988:Soil Microbiology; D013237:Stereoisomerism; D013696:Temperature
chemical_list: C522704:2,2-dimethylcyclopropanecarboxamide; D000464:Alginates; D003521:Cyclopropanes; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D000581:Amidohydrolases; C019665:amidase