Lipase-catalyzed synthesis of isoamyl butyrate A kinetic study.

Hari Krishna, S. and Karanth, N. G. (2001) Lipase-catalyzed synthesis of isoamyl butyrate A kinetic study. Biochimica et Biophysica Acta, 1547. pp. 262-267. ISSN 0167-4838

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Abstract

Kinetics of lipase-catalyzed esterification of butyric acid and isoamyl alcohol have been investigated. The reaction rate could be described in terms of the Michaelis^Menten equation with a Ping-Pong Bi-Bi mechanism and competitive inhibition by both the substrates. No evidence of any significant diffusional limitations was detected that could affect the kinetics. The values of the apparent kinetic parameters were computed as: Vmax = 11.72 Wmol/min/mg; KM; Acid = 0.00303 M; KM; Alcohol =0.00306 M; Ki; Acid = 1.05 M; and Ki; Alcohol = 6.55 M. This study indicates a competitive enzyme inhibition by butyric acid during lipase-catalyzed esterification reaction. Butyric acid, being a short-chain polar acid, concentrates in the microaqueous layer and causes a pH drop in the enzyme microenvironment leading to enzyme inactivation. Butyric acid binds to acyl^enzyme complex unproductively to yield a dead-end intermediate that can no longer give rise to an ester. High concentration of butyric acid gave rise to inactivation of the biocatalyst in addition to dead-end inhibition.

Item Type:	Article
Additional Information:	Copyright of this article belongs to Elsevier Ltd.
Uncontrolled Keywords:	Esteri¢cation; Acid inhibition; Isoamyl butyrate; Kinetics; Lipase; Organic solvent; Ping-Pong Bi-Bi mechanism
Subjects:	600 Technology > 05 Chemical engineering > 04 Fermentation Technology
Divisions:	Fermentation Technology and Bioengineering
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	26 Jun 2007 06:37
Last Modified:	28 Dec 2011 09:28
URI:	http://ir.cftri.res.in/id/eprint/1265

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