Immobilization of Candida antarctica Lipase on Nanomaterials and Investigation of the Enzyme Activity and Enantioselecti

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Immobilization of Candida antarctica Lipase on Nanomaterials and Investigation of the Enzyme Activity and Enantioselectivity Gülcan Coşkun 1 & Zafer Çıplak 1 & Nuray Yıldız 1 & Ülkü Mehmetoğlu 1 Received: 11 May 2020 / Accepted: 29 September 2020/ # Springer Science+Business Media, LLC, part of Springer Nature 2020

Abstract

This study defines the lipase immobilization protocol and enzymatic kinetic resolution of 1-phenyl ethanol with the use of immobilized lipases (LI) as a biocatalyst. Commercially available lipase Candida antarctica B (Cal-B) was immobilized onto graphene oxide (GO), iron oxide (Fe3O4) nanoparticles, and graphene oxide/iron oxide (GO/Fe3O4) nanocomposites. Characterization of pure and enzyme-loaded supports was carried out by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The influences of pH, temperature, immobilization time, crosslinker concentration, glutaraldehyde (GLA), epichlorohydrin (EPH), and surfactant concentrations (Tween 80 and Triton X-100) on the catalytic activity were evaluated for these three immobilized biocatalysts. The highest immobilized enzyme activities were 15.03 U/mg, 14.72 U/mg, and 13.56 U/mg for GO-GLA-CalB, Fe3O4-GLA-CalB, and GO/Fe3O4-GLA-CalB, respectively. Moreover, enantioselectivity and reusability of these immobilized lipases were compared for the kinetic resolution of 1-phenyl ethanol, using toluene as organic solvent and vinyl acetate as acyl donor. The highest values of enantiomeric excess (ees = 99%), enantioselectivity (E = 507.74), and conversion (c = 50.73%) were obtained by using lipase immobilized onto graphene oxide (GO-GLA-CalB). It was obtained that this enzymatic process may be repeated five times without important loss of enantioselectivity. Keywords Candida antarctica lipase . Immobilization . Nanoparticles . Enzyme activity . Kinetic resolution

* Ülkü Mehmetoğlu [email protected]

1

Department of Chemical Engineering, Ankara University, Tandoğan, 06100 Ankara, Turkey

Applied Biochemistry and Biotechnology

Introduction Lipases (triacylglycerol acyl hydrolases, EC 3.1.1.3) are widely used enzymes in biocatalysts that have essential roles in organic chemistry since they have a broad specificity and can react with various substrates [1]. The solubility of lipases in water is very poor, that is why the reaction usually occurs at an aqueous-organic interface at which they perform better catalytic activity than at aqueous solution [2, 3]. Lipases can hydrolyze triglycerides at lipid-water interfaces since the hydrolytic reaction is reversible in a nonaqueous medium; they can also catalyze the formation of acylglycerols from glycerol and free fatty acids [4]. Applications of lipases in different industries have been steadily increasing, especially during the last few years. They have been used particularly in the food industry, in the pharmaceutical industry, in the pulp and paper industries, and in the chemical industries [5]. Enantioselectivity of the lipases has significant enzyme property for man