title: Immobilization of an L-aminoacylase-producing strain of Aspergillus oryzae into gelatin pellets and its application in the resolution of D,L-methionine.
abstract: The conditions for immobilization of an l-aminoacylase-producing strain of Aspergillus oryzae in gelatin and the enzymic characteristics of the immobilized pellets were studied. The optimal concentrations of gelatin, glutaraldehyde and ethyldiamine and time of immobilization were determined. Scanning electron micrographs reveal the cross-linked structure differences between the native and immobilized pellets. Optimum pH and temperature of the native and immobilized pellets were determined. Effects of ionic strength and substrate concentration on relative activity of the native and immobilized pellets were investigated in detail. The immobilized pellets were more stable over broader temperature and pH ranges. In addition, the immobilized pellets showed stable activity under operational and storage conditions. The immobilized pellets lost about 20% of their initial activity after five cycles of reuse. The results reported in this paper show the potential for using the immobilized A. oryzae pellets to resolve d,l-methionine.
authors.affiliation: Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China. yiyuan@public.tpt.tj.cn
authors.forename: Ying-jin
authors.initials: YJ
authors.lastname: Yuan Yj
authors.forename: Shu-hao
authors.initials: SH
authors.lastname: Wang Sh
authors.forename: Zheng-xiao
authors.initials: ZX
authors.lastname: Song Zx
authors.forename: Rui-chang
authors.initials: RC
authors.lastname: Gao Rc
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D001236:Aspergillus oryzae / Q000201:enzymology*; D018914:Cells, Immobilized / Q000201:enzymology*; D005780:Gelatin; D007700:Kinetics; D008715:Methionine / Q000302:isolation & purification*; D023822:Tissue Engineering
chemical_list: D005780:Gelatin; D008715:Methionine; D000581:Amidohydrolases; C019672:aminoacylase I