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Crosslinked aggregates of Rhizopus oryzae lipase as industrial biocatalysts: Preparation, optimization, characterization, and application for enantioselective resolution reactions
Author(s) -
Kartal Funda,
Kilinc Ali
Publication year - 2012
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.1571
Subject(s) - chemistry , lipase , hydrolysis , kinetic resolution , rhizopus oryzae , candida antarctica , enantiomeric excess , organic chemistry , aqueous solution , transesterification , chromatography , enantioselective synthesis , catalysis , enzyme , fermentation
Abstract Lipase from Rhizopus oryzae (ROL) was immobilized as crosslinked enzyme aggregate (CLEA) via precipitation with ammonium sulfate and simultaneous crosslinking with glutaraldehyde. The optimum conditions of the immobilization process were determined. Lipase CLEAs showed a twofold increase in activity when Tween 80‐pretreated lipase was used for CLEA preparation. CLEAs were shown to have several advantages compared to free lipase. CLEAs were more stable at 50°C and 60°C as well as for a wide range of pH. After incubation at 50°C, CLEA showed 74% of initial activity whereas free enzyme was totally inactivated. Reduction of Schiff bases has been performed for the first time in the CLEA preparation process significantly improving the chemically modified CLEAs' reusability, thus providing an enzyme with high potential for recycling even under aqueous reaction conditions where enzyme leakage is, in general, one of the major problems. The CLEA retained 91% activity after 10 cycles in aqueous medium. The immobilized enzyme was used for kinetic resolution reactions. Results showed that immobilization had an enhancing effect on the conversion ( c ) as well as on the enantiomeric ratio ( E ). ROL CLEA displayed five times higher enantioselectivity for the hydrolysis of ( R , S )‐1‐phenylethyl acetate and likewise 1.5 times higher enantioselectivity for the transesterification of racemic ( R – S )‐1‐phenylethanol with vinylacetate. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 937–945, 2012 This article was published online on June 26, 2012. An edit was subsequently requested. This notice is included in the online and print versions to indicate that both have been corrected [27 June 2012].