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Stability of hydrolase enzymes in ionic liquids
Author(s) -
HernándezFernández F. J.,
Ríos A. P. de los,
TomásAlonso F.,
Gómez D.,
Víllora G.
Publication year - 2009
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.20227
Subject(s) - chemistry , candida antarctica , ionic liquid , hydrolysis , dicyanamide , organic chemistry , lipase , thermal stability , imide , enzyme , catalysis
In this work we attempted to evaluate the stability of penicillin G acylase (PGA) from Escherichia coli in their native form and free Candida antarctica lipase B (CaLB) in ionic liquids (ILs) at low water content. The hydrolysis of penicillin G to 6‐aminopenicillanic acid (6‐APA), and phenyl acetic acid (PAA) catalysed by PGA and the synthesis of butyl butyrate from vinyl butyrate and 1‐butanol catalysed by CaLB were chosen as activity tests. The influence of these new solvents on enzyme stability was studied by incubating the enzyme (PGA or CaLB) in ILs based on dialkylimidazolium cations associated with perfluorinated and dicyanamide anions at a given temperature. Stability studies indicate that CaLB and PGA exhibited greater stability in water‐immiscible ILs than in water‐miscible ILs. Specifically, native PGA shows greater stability in IL media than in organic solvents. For example, a half‐life time of 23 h was obtained in 1‐ethyl‐3‐methylimidazolium bis{(trifluoromethyl)sulfonyl}imide, $[{\rm emim}^ + ][{\rm NTf}_2^ - ]$ , which was about 2000‐fold higher than that in 2‐propanol. The higher half‐life time of CaLB was observed in $[{\rm omim}^ + ][{\rm PF}_6^ - ]$ ( t 1/2 = 84 h).