title: Whole-Cell Biocatalytic Synthesis of Cinnamyl Acetate with a Novel Esterase from the DNA Library of Acinetobacter hemolyticus.
abstract: Cinnamyl acetate has a wide application in the flavor and fragrance industry because of its sweet, balsamic, and floral odor. Up to now, lipases have been mainly used in enzyme-mediated synthesis of cinnamyl acetate, whereas esterases are used in only a few cases. Moreover, the use of purified enzymes is often a disadvantage, which leads to increases of the production costs. In this paper, a genomic DNA library of Acinetobacter hemolyticus was constructed, and a novel esterase (EstK1) was identified. After expression in Escherichia coli, the whole-cell catalyst of EstK1 displayed high transesterification activity to produce cinnamyl acetate in nonaqueous systems. Furthermore, under optimal conditions (vinyl acetate as acyl donor, isooctane as solvent, molar ratio 1:4, temperature 40 °C), the conversion ratio of cinnamyl alcohol could be up to 94.1% at 1 h, and it reached an even higher level (97.1%) at 2 h.
authors.affiliation: College of Food Science and Engineering, Ocean University of China , Qingdao 266003, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Dong
authors.affiliation: Istituto di Chimica del Riconoscimento Molecolare, CNR , v. Mario Bianco 9, 20131 Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Secundo
authors.affiliation: College of Food Science and Engineering, Ocean University of China , Qingdao 266003, China.
authors.forename: Changhu
authors.initials: C
authors.lastname: Xue
authors.affiliation: College of Food Science and Engineering, Ocean University of China , Qingdao 266003, China.
authors.forename: Xiangzhao
authors.identifier: http://orcid.org/0000-0002-6315-1338
authors.initials: X
authors.lastname: Mao
mesh_terms: D000150:Acinetobacter / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D055162:Biocatalysis; D002934:Cinnamates / Q000378:metabolism*; D004950:Esterases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015723:Gene Library; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D002934:Cinnamates; D004950:Esterases; C526329:cinnamyl acetate
keywords: acetic esters; cinnamyl acetate; esterase; genomic DNA library; transesterification; whole-cell biocatalyst