Improvement of Lipase Catalytic Properties by Immobilization in Hybrid Matrices

Lipases are enzymes particularly amenable for immobilization by entrapment methods, as they can work equally well in aqueous or non-conventional media and long-time stability of enzyme activity and enantioselectivity is needed to elaborate more efficient bioprocesses. The improvement of Pseudomonas fluorescens (Amano AK) lipase characteristics was investigated by optimizing the immobilization procedure in hybrid organic-inorganic matrices using ionic liquids as additives. Ionic liquids containing a more hydrophobic alkyl group in the cationic moiety are beneficial for the activity of immobilized lipase. Silanes with alkyl- or aryl nonhydrolizable groups used as precursors in combination with tetramethoxysilane could generate composites with higher enantioselectivity compared to the native enzyme in acylation reactions of secondary alcohols. The optimal effect on both activity and enantioselectivity was achieved for the composite made from octyltrimethoxysilane and tetramethoxysilane at 1:1 molar ratio (60% increase of total activity following immobilization and enantiomeric ratio of 30). Ionic liquids also demonstrated valuable properties as reaction media for the studied reactions, comparable with the usual organic solvent, hexane.

Authors:

• C. Zarcula
• R. Croitoru
• L. Corîci
• C. Csunderlik
• F. Peter

Keywords:

• Ionic liquids
• lipase
• enantioselectivity
• sol-gelimmobilization

References:

[1] European Technology Platform on Sustainable Chemistry (2007, May)
Industrial or white biotechnology: a driver of sustainable growth in
Europe. Available: http://www.europabio.org/TPWhite/IB_Vision.pdf.
[2] M. Breuer, K. Ditrich, T. Habicher, B. Hauer, M. Kesseler, R. St├╝rmer,
T. Zelinski, ÔÇ×Industrial methods for the production of optically active
intermediates", Angew. Chem. Int. Ed., vol. 43, nr. 7, pp. 788-824, 2004.
[3] K. Buchholz, V. Kasche, U.T. Bornscheuer, Biocatalysts and enzyme
technology, Weinheim: Wiley-VCH Verlag, 2004, pp. 197-279.
[4] C. Mateo, J.M. Palomo, G. Fernandez-Lorente, J.M. Guisan, R.
Fernandez-Lafuente, "Improvement of enzyme activity, stability and
selectivity via immobilization techniques", Enzyme Microb. Technol.,
vol. 40, pp. 1451-1463, 2007.
[5] L. Cao, Carrier-bound immobilized enzymes: principles, applications
and design, Weinheim: Wiley-VCH, Verlag, 2005, pp. 16-36.
[6] R.A. Sheldon, "Enzyme immobilization: the quest for optimum
performance", Adv. Synth. Catal., vol 349, pp. 1289-1307, 2007.
[7] L. Betancor, H.R. Luckarift, "Bioinspired enzyme encapsulation for
biocatalysis", Trends Biotechnol., vol. 26, nr. 10, pp. 566-572, 2008.
[8] J. Livage, T. Coradin, C. Roux, ÔÇ×Encapsulation of biomolecules in silica
gels", J. Phys.: Condens. Matter, vol. 13, pp. 673-691, 2001.
[9] M.T. Reetz, P. Tielmann, W. Wiesenhöfer, W. Könen, A. Zonta,
ÔÇ×Second generation sol-gel encapsulated lipases: robust heterogeneous
biocatalysts", Adv. Synth. Catal., vol. 345, pp. 717-728, 2003.
[10] F. Peter, L. Poppe, C. Kiss, E. Szocs-Bir├│, G. Preda, C. Zarcula, A.
Olteanu, "Influence of precursors and additives on microbial lipases
stabilized by sol-gel entrapment", Biocat. Biotrans., vol. 23, nr. 3/4, pp.
251-260, 2005.
[11] A.C. Pierre, "The sol-gel encapsulation of biocatalysts", Biocat.
Biotrans., vol. 22, nr.3, pp. 145-170, 2004.
[12] S.H. Lee, T.T.N. Doan, S.H. Ha, W.-J Chang, Y.-M Koo, "Influence of
ionic liquids as additives on sol-gel immobilized lipase", J. Mol. Cat. B:
Enzymatic., vol. 47 pp. 129-134, 2007.
[13] C. Kiss, C. Zarcula, C. Csunderlik, F. Peter, "Enantioselective acylation
of secondary alcohols by biocatalysis with sol-gel immobilized
Pseudomonas fluorescens lipase, Rev. Chim. (Bucharest), vol. 58, nr. 8,
pp. 799-804, 2007.
[14] G. C.-S Chen. Y. Fujimoto, G. Girdauskas, C.J. Sih, "Quantitative
analyses of biochemical kinetic resolutions of enantiomers", J. Am.
Chem. Soc., vol. 104, pp. 7294-7299, 1982.
[15] F.Van Rantwijk, R.M. Lau, R.A. Sheldon, "Biocatalytic transformations
in ionic liquids", Trends Biotechnol., vol, 21, pp. 131-138, 2003.
[16] S.H. Lee, T.T.N. Doan, S.H. Ha, W.-J. Chang, Y.-M. Koo, "Influence of
ionic liquids as additives on sol-gel immobilized lipase", J. Mol. Cat. B:
Enzymatic., vol. 47, pp. 129-134, 2007.
[17] Y. Zhou, J.H. Schattka, M. Antonietti, "Room-temeperature ionic liquids
as template to monolythic mesoporous silica with wormlike pores via a
sol-gel nanocasting technique", Nano Lett., vol. 4, nr. 3, pp. 477-481,
2004.
[18] A. Ghanem, W. Schurig, "Lipase-catalyzed irreversible
transesterification of secondary alcohols using isopropenyl acetate",
Chem. Monthly, vol. 134, pp. 1151-1157, 2003.
[19] Z. Yang, W. Pan, "Ionic liquids: green solvnets for nonaqueous
biocatalysis", Enzyme Microb. Technol., vol. 37, pp.19-28, 2005.