Immobilization of laccase in a sponge-like hydrogel for enhanced durability in enzymatic degradation of dye pollutants

J Colloid Interface Sci. 2015 Jul 15:450:353-360. doi: 10.1016/j.jcis.2015.03.037. Epub 2015 Mar 27.

Abstract

A highly stable and efficient biocatalyst was fabricated by encapsulating Trametes versicolor laccase within a chitosan grafted polyacrylamide hydrogel (denoted as Lac-PAM-CTS). Scanning electron microscopy and nitrogen adsorption-desorption tests demonstrated that channels of diameter of 10-20 μm were regularly distributed throughout the sponge-like Lac-PAM-CTS. Besides, there were massive mesopores and macropores in the lamellar walls of the hydrogel. Such a network structure reduced the diffusion resistance of the hydrogel to the target substrates. The recovered activity of the obtained Lac-PAM-CTS was 40.8%. As compared to free laccase, the Lac-PAM-CTS showed enhanced thermal and chemical stability. The positive surface charge of the Lac-PAM-CTS endowed it with a pre-enrichment effect in the treatment of anionic dyes. In a continuous six-cycle batch decoloration of Malachite Green, the Lac-PAM-CTS showed much better durability than the free laccase. The results here suggest that sponge-like hydrogel is a good supporting matrix for laccase.

Keywords: Biocatalys; Chitosan; Decoloration; Entrapment; Pre-enrichment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Enzyme Stability
  • Enzymes, Immobilized / chemistry*
  • Fungal Proteins / chemistry*
  • Hydrogels / chemistry*
  • Laccase / chemistry*
  • Rosaniline Dyes / chemistry*
  • Trametes / enzymology*
  • Water Pollutants, Chemical / chemistry*

Substances

  • Enzymes, Immobilized
  • Fungal Proteins
  • Hydrogels
  • Rosaniline Dyes
  • Water Pollutants, Chemical
  • malachite green
  • Laccase