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Immobilization of Candida rugosa lipase on hexagonal mesoporous silicas and selective esterification in nonaqueous medium

Paper ID Volume ID Publish Year Pages File Format Full-Text
3447 171 2013 9 PDF Available
Title
Immobilization of Candida rugosa lipase on hexagonal mesoporous silicas and selective esterification in nonaqueous medium
Abstract

Candida rugosa lipases (CRLs) immobilized by physical adsorption, cross-linking and covalent binding methods on a MSU-H type mesoporous silica previously modified organically by different strategies, respectively, were examined as biocatalysts for esterification of conjugated linoleic acid (CLA) and ethanol in nonaqueous medium. MSU-H silica was modified by nonionic surfactant of triblock copolymer Pluronic P123, amino-functionalization and glutaraldehyde-grafting and confirmed by FT-IR analysis. Interaction mechanisms of CRLs and supports involve covalent and non-covalent interactions including electrostatic repulsion and hydrophobic interaction at pH 7. The immobilized CRLs containing surfactant were prepared by cross-linking via entrapping CRL aggregates inside the pores of silicas. The surfactant located inside the silicas could interfacially activate the immobilized CRLs and favored catalytic esterification. The biocatalyst containing 38 wt.% of surfactant afforded 1111.1 U/mg of specific activity about eight times higher than soluble CRL, and maximal 56.7% of total CLA esterification with 96.5% of 9c, 11t-CLA isomer esterification degree. The immobilized-CRL with 64.5 mg/g of loading amount of protein exhibited maximal hydrolytic activity of 2945.3 U/g-support for grafting glutaraldehyde. This derivative showed a high level of esterification activity and operational stability and remained 43.2–46.9% of total esterification for 32 h consecutive four runs.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Different strategies of modification of MSU-H mesoporous silica have been employed. ► Immobilization of Candida rugosa lipase (CRL) on MSU-H silicas was achieved. ► Bioconversion of conjugated linoleic acid (CLA) to its ethyl ester has been developed. ► The biocatalysts exhibit a high level of esterification activity and steady reuse. ► The mechanism of adsorption of CRL on silica has been presented.

Keywords
Biocatalysis; Lipase; Immobilization; Enzyme technology; Mesoporous silica; Conjugated linoleic acid
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Immobilization of Candida rugosa lipase on hexagonal mesoporous silicas and selective esterification in nonaqueous medium
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Publisher
Database: Elsevier - ScienceDirect
Journal: Biochemical Engineering Journal - Volume 70, 15 January 2013, Pages 97–105
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us