Lysozyme immobilized on micro-sized magnetic particles: kinetic parameters at wine pH

Appl Biochem Biotechnol. 2012 Apr;166(7):1736-46. doi: 10.1007/s12010-012-9577-z. Epub 2012 Feb 11.

Abstract

In order to use lysozyme as an anti-microbial agent during the winemaking process, hen egg-white lysozyme (LYZ) was covalently immobilized on two different micro-size magnetic particles (tosyl-activated and carboxylated, TSA and CA, respectively). A cell suspension of Oenococcus oeni, an oenological strain involved in the winemaking process, was utilized as LYZ substrate. Both a kinetic study and a study of the stability of free and immobilized LYZ were performed in McIlvane buffer at pH 3.2, that is the average minimum pH value in wine. The activity and kinetic parameters measured for the free LYZ at pH 3.2 are lower than those reported at the optimum pH (4.5); however the residual activity at pH 3.2 is sufficient to be of interest for further immobilization and applications in winemaking. All kinetic parameters of both biocatalysts (LYZ-CA and LYZ-TSA) are altered after immobilization, probably due to the structural modifications in the active site caused by covalent attachment to the supports. The half-life calculated at 25 °C was 39 h for free LYZ, while it increased to 280 and 134 h for LYZ-TSA and LYZ-CA, respectively. This result indicates that immobilization improves the enzyme stability and that LYZ can be utilized in wine applications in its immobilized forms. In addition, LYZ-TSA seems to be the best biocatalyst for further applications in winemaking.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chickens
  • Enzyme Stability
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism*
  • Half-Life
  • Hot Temperature
  • Hydrogen-Ion Concentration
  • Kinetics
  • Magnetite Nanoparticles / chemistry*
  • Muramidase / chemistry
  • Muramidase / metabolism*
  • Oenococcus / metabolism*
  • Particle Size
  • Tosyl Compounds / chemistry
  • Wine*

Substances

  • Enzymes, Immobilized
  • Magnetite Nanoparticles
  • Tosyl Compounds
  • hen egg lysozyme
  • Muramidase