Multipoint covalent immobilization of lipase on chitosan hybrid hydrogels: influence of the polyelectrolyte complex type and chemical modification on the catalytic properties of the biocatalysts

J Ind Microbiol Biotechnol. 2011 Aug;38(8):1055-66. doi: 10.1007/s10295-010-0880-9. Epub 2010 Oct 5.

Abstract

This work aimed at the production of stabilized derivatives of Thermomyces lanuginosus lipase (TLL) by multipoint covalent immobilization of the enzyme on chitosan-based matrices. The resulting biocatalysts were tested for synthesis of biodiesel by ethanolysis of palm oil. Different hydrogels were prepared: chitosan alone and in polyelectrolyte complexes (PEC) with κ-carrageenan, gelatin, alginate, and polyvinyl alcohol (PVA). The obtained supports were chemically modified with 2,4,6-trinitrobenzene sulfonic acid (TNBS) to increase support hydrophobicity, followed by activation with different agents such as glycidol (GLY), epichlorohydrin (EPI), and glutaraldehyde (GLU). The chitosan-alginate hydrogel, chemically modified with TNBS, provided derivatives with higher apparent hydrolytic activity (HA(app)) and thermal stability, being up to 45-fold more stable than soluble lipase. The maximum load of immobilized enzyme was 17.5 mg g(-1) of gel for GLU, 7.76 mg g(-1) of gel for GLY, and 7.65 mg g(-1) of gel for EPI derivatives, the latter presenting the maximum apparent hydrolytic activity (364.8 IU g(-1) of gel). The three derivatives catalyzed conversion of palm oil to biodiesel, but chitosan-alginate-TNBS activated via GLY and EPI led to higher recovered activities of the enzyme. Thus, this is a more attractive option for both hydrolysis and transesterification of vegetable oils using immobilized TLL, although industrial application of this biocatalyst still demands further improvements in its half-life to make the enzymatic process economically attractive.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alginates / chemistry
  • Ascomycota / metabolism*
  • Biofuels
  • Biotechnology
  • Carrageenan / chemistry
  • Carrageenan / metabolism
  • Catalysis
  • Chitosan / chemistry*
  • Electrolytes / chemistry
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism
  • Epoxy Compounds / chemistry
  • Esterification
  • Glucuronic Acid / chemistry
  • Glutaral / chemistry
  • Half-Life
  • Hexuronic Acids / chemistry
  • Hydrogels / chemistry*
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Lipase / chemistry*
  • Lipase / metabolism
  • Polyvinyl Alcohol / chemistry
  • Propanols / chemistry

Substances

  • Alginates
  • Biofuels
  • Electrolytes
  • Enzymes, Immobilized
  • Epoxy Compounds
  • Hexuronic Acids
  • Hydrogels
  • Propanols
  • Glucuronic Acid
  • Carrageenan
  • Polyvinyl Alcohol
  • Chitosan
  • Lipase
  • glycidol
  • Glutaral