Improving activity and enantioselectivity of lipase via immobilization on macroporous resin for resolution of racemic 1- phenylethanol in non-aqueous medium

Xiang Li,Yunjun Yan,Shuangshuang Huang,Li Xu

doi:10.1186/1472-6750-13-92

Xiang Li, Yunjun Yan + Show 2 more

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https://doi.org/10.1186/1472-6750-13-92

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Abstract

BackgroundBurkholderia cepacia lipase (BCL) has been proved to be capable of resolution reactions. However, its free form usually exhibits low stability, bad resistance and no reusability, which restrict its further industrial applications. Therefore, it is of great importance to improve the catalytic performance of free lipase in non-aqueous medium.ResultsIn this work, macroporous resin NKA (MPR-NKA) was utilized as support for lipase immobilization. Racemic transesterification of 1-phenylethanol with vinyl acetate was chosen as model reaction. Compared with its free form, the enzyme activity and enantioselectivity (ees) of the immobilized lipase have been significantly enhanced. The immobilized BCL exhibited a satisfactory thermostability over a wide range of temperature (from 10 to 65°C) and an excellent catalytic efficiency. After being used for more than 30 successive batches, the immobilized lipase still kept most of its activity. In comparison with other immobilized lipases, the immobilized BCL also exhibits better catalytic efficiency, which indicates a significant potential in industrial applications.ConclusionThe results of this study have proved that MPR-NKA was an excellent support for immobilization of lipase via the methods of N2 adsorption–desorption, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform-infrared spectroscopy (FT-IR). The improvement of enzyme activity and ees for the immobilized lipase was closely correlated with the alteration of its secondary structure. This information may contribute to a better understanding of the mechanism of immobilization and enzymatic biotransformation in non-aqueous medium.

Highlights

Burkholderia cepacia lipase (BCL) has been proved to be capable of resolution reactions
Immobilized lipases via adsorption methods have been used in many reactions, such as ester synthesis, biodiesel production and enrichment of polyunsaturated fatty acids [5,11,12]
Based on the above analysis, the main objectives of this work are: (1) to compare the properties of the free lipase and the immobilized lipase on MPRs based on the reaction parameters, such as temperature, water content, substrate molar ratio, and reaction time; (2) to investigate probable mechanism for the significant improvement of enzyme activity and enantioselectivity through various characterizations of the immobilized lipase; and (3) further to compare the catalytic efficiency between the immobilized BCL and other immobilized lipases

Summary

Introduction

Burkholderia cepacia lipase (BCL) has been proved to be capable of resolution reactions. It is of great importance to improve the catalytic performance of free lipase in non-aqueous medium. Immobilization has been proved to be one of the most useful strategies to improve catalytic properties of free enzyme [8]. Immobilized lipases via adsorption methods have been used in many reactions, such as ester synthesis, biodiesel production and enrichment of polyunsaturated fatty acids [5,11,12]. Many studies showed that immobilization could greatly enhance the catalytic performance of enzyme [14,15], till to the best of our knowledge, it is still unclear that why immobilization can enhance the activity and tolerance of lipases. It is important to elucidate the possible mechanism of this enhancement

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