title: Immobilization of laccase in a sponge-like hydrogel for enhanced durability in enzymatic degradation of dye pollutants.
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.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
authors.forename: Hongfei
authors.initials: H
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
authors.forename: Wenguang
authors.initials: W
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China. Electronic address: sjzhang@nju.edu.cn.
authors.forename: Shujuan
authors.initials: S
authors.lastname: Zhang
mesh_terms: D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D042845:Laccase / Q000737:chemistry*; D012394:Rosaniline Dyes / Q000737:chemistry*; D055454:Trametes / Q000201:enzymology*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D020100:Hydrogels; D012394:Rosaniline Dyes; D014874:Water Pollutants, Chemical; C005095:malachite green; D042845:Laccase
keywords: Biocatalys; Chitosan; Decoloration; Entrapment; Pre-enrichment