title: Kinetic modeling of lipase-catalyzed esterification reaction between oleic acid and trimethylolpropane: a simplified model for multi-substrate multi-product ping-pong mechanisms.
abstract: Kinetic models are among the tools that can be used for optimization of biocatalytic reactions as well as for facilitating process design and upscaling in order to improve productivity and economy of these processes. Mechanism pathways for multi-substrate multi-product enzyme-catalyzed reactions can become very complex and lead to kinetic models comprising several tens of terms. Hence the models comprise too many parameters, which are in general highly correlated and their estimations are often prone to huge errors. In this study, Novozym(®) 435 catalyzed esterification reaction between oleic acid (OA) and trimethylolpropane (TMP) with continuous removal of side-product (water) was carried out as an example for reactions that follow multi-substrate multi-product ping-pong mechanisms. A kinetic model was developed based on a simplified ping-pong mechanism proposed for the reaction. The model considered both enzymatic and spontaneous reactions involved and also the effect of product removal during the reaction. The kinetic model parameters were estimated using nonlinear curve fitting through unconstrained optimization methodology and the model was verified by using empirical data from different experiments and showed good predictability of the reaction under different conditions. This approach can be applied to similar biocatalytic processes to facilitate their optimization and design.
authors.affiliation: Dept. of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, Box 124, 221 00, Lund, Sweden.
authors.forename: Amin
authors.initials: A
authors.lastname: Bornadel
authors.forename: Cecilia Orellana
authors.initials: CO
authors.lastname: Akerman
authors.forename: Patrick
authors.initials: P
authors.lastname: Adlercreutz
authors.forename: Rajni
authors.initials: R
authors.lastname: Hatti-Kaul
authors.forename: Niklas
authors.initials: N
authors.lastname: Borg
mesh_terms: D055162:Biocatalysis; D004951:Esterification; D007700:Kinetics; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D019301:Oleic Acid / Q000096:biosynthesis* / Q000737:chemistry; D011409:Propylene Glycols / Q000737:chemistry / Q000378:metabolism*; D014867:Water / Q000737:chemistry
chemical_list: D011409:Propylene Glycols; D014867:Water; C018163:trimethylolpropane; D019301:Oleic Acid; D008049:Lipase
keywords: Novozym®435; biocatalytic processes; nonlinear curve fitting; side-product removal; substituted-enzyme mechanism