A Multi-Scale Approach to Modeling the Interfacial Reaction Kinetics of Lipases with Emphasis on Enzyme Adsorption at Water-Oil Interfaces

Sherly Rusli,Matthias Kraume,Janna Grabowski,Anja Drews

doi:10.3390/pr8091082

Sherly Rusli, Matthias Kraume + Show 2 more

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https://doi.org/10.3390/pr8091082

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Abstract

The enzymatic hydrolysis of triglycerides with lipases (EC 3.1.1.3.) involves substrates from both water and oil phases, with the enzyme molecules adsorbed at the water-oil (w/o) interface. The reaction rate depends on lipase concentration at the interface and the available interfacial area in the emulsion. In emulsions with large drops, the reaction rate is limited by the surface area. This effect must be taken into account while modelling the reaction. However, determination of the interfacial saturation is not a trivial matter, as enzyme molecules have the tendency to unfold on the interface, and form multi-layer, rendering many enzyme molecules unavailable for the reaction. A multi-scale approach is needed to determine the saturation concentration with specific interfacial area so that it can be extrapolated to droplet swarms. This work explicitly highlights the correlation between interfacial adsorption and reaction kinetics, by integration of the adsorption kinetics into the enzymatic reaction. The rate constants were fitted globally against data from both single droplet and drop swarm experiments. The amount of adsorbed enzymes on the interface was measured in a single drop with a certain surface area, and the enzyme interfacial loading was estimated by Langmuir adsorption isotherm.

Highlights

Lipases (EC. 3.1.1.3.) have gained popularity in industrial applications as the main catalyst for hydrolyzing lipids
The reaction can be done in mild conditions (30 to 60 ◦C at atmospheric pressure) compared to the commercial fat splitting process, the Colgate Emery, which is performed at high pressure and high temperature (300 ◦C at 50 bar) [1,2]
Commercial enzyme Lipomod 034P (L34P) from Candida rugosa was provided by Biocatalyst Ltd., Wales, UK, with an activity of 115,000 Ug−1 based on olive oil substrate

Summary

Introduction

Lipases (EC. 3.1.1.3.) have gained popularity in industrial applications as the main catalyst for hydrolyzing lipids. The reaction can be done in mild conditions (30 to 60 ◦C at atmospheric pressure) compared to the commercial fat splitting process, the Colgate Emery, which is performed at high pressure and high temperature (300 ◦C at 50 bar) [1,2]. In addition to energy saving potential and less purification efforts, the enzymatic process preserves the quality of fatty acids without exposing the molecules to harsh temperatures. This is important for processing temperature sensitive materials such as ricinoleic acid [3]. Numerical modelling is a valuable tool in developing such processes, to determine the optimum over a wide range of process conditions. For the development of any process simulations, the availability of reliable kinetic models are an integral part [4]

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