Dye decolorisation by laccase immobilised in lens-shaped poly(vinyl alcohol) hydrogel capsules

Abstract

In this study, laccase (from Trametes versicolor, 8.3 U mgenz−1) was used for the decolorisation of Saturn Blue L4G (10 mg L−1). The efficiency of the decolorisation (ratio between the amount of decolorised dye and initial amount of dye) by a free enzyme was 48 % and the decolorisation rate was determined at 2.11 × 10−3 mgdye mgenz−1 min−1. After immobilisation in lens-shaped poly(vinyl alcohol) hydrogel capsules LentiKats® Biocatalyst (LB) (concentration of immobilised enzyme: 4 mg per g of particles; volume-loading rate of LB: 10 g per 100 mL of medium), the enzyme retained 16.1 % of its original activity (1.34 U mgenz−1). Immobilised laccase was used for the dye decolorisation in 130 repeated batch tests with 71 % efficiency (LB activity: 7 × 10−3 mgdye min−1 gLB−1). In continuous mode (after 716.5 h), the efficiency of the dye decolorisation was 48 % (LB activity: 3.3 × 10−4 mgdye min/−1 gLB−1).

Developments in support materials for immobilization of oxidoreductases: A comprehensive review

“…PVA is rich in hydroxyl groups, and is a strongly hydrophilic material which may be easily modified to achieve a suitable enzymatic matrix. For instance, PVA was used as fibers, beads or microspheres for covalent immobilization of horseradish peroxidase and for entrapment and encapsulation of laccase [100][101][102]. Chhabra and his team entrapped laccase from Cyathus bulleri in polyvinyl alcohol beads for degradation of azo-dyes in a continuous packed column.…”

“…The multiplicity of the possible supports caused that their proper selection is strongly governed by the type of the enzyme, immobilization technique and undesirable compound that has to be removed. For instance for immobilization of laccase from Trametes versicolor, the most commonly applied oxidoreductase for environmental application, materials of different hydrophilicity and functional moieties (-OH, -NH 2 , C=O) of organic, inorganic and hybrid origin, such as chitosan and polyvinyl alcohol capsules [76,101], mesoporous silica and Fullere C 60 [121,148] as well as magnetic chitosan/clay beads or poly(4-vinyl pyridine)/Cu(II) magnetic beads [165,184] were applied. Also mushroom tyrosinase was immobilized using wide range of support materials, such as cellulose paper [83], silica gel [130] and chitosan/clay and chitosan/alginate magnetic capsules [171,174].…”

Applications and immobilization strategies of the copper-centred laccase enzyme; a review

“…Also PVA polymers are reported to have high mechanical strength which is an important attribute for an enzyme support [ 118 ]. Different forms of PVA such as particles [ 372 ], beads [ 118 ], cryogels [ 431 ], hydrogels [ 562 , 563 ], and microspheres [ 560 ] have been used to entrap laccase. For example, Gonzalez-Coronel et al [ 434 ], entrapped laccase in Lentikats (lentil shaped particles of PVA) and obtained 89% activity recovery, 0% leaching, and 90% retained activity after 84 h. Laccase entrapped in PVA microspheres demonstrated stability on organic solvents (methanol, ethanol, acetone, and DMSO) for concentrations up to 40% [ 560 ].…”

Enhanced Catalytic Dye Decolorization by Microencapsulation of Laccase from P. Sanguineus CS43 in Natural and Synthetic Polymers

“…Compared with our PSS preparation, alginate/chitosan microcapsules reported in [ 38 ] degraded 2.6 times more dye, albeit with a 135-fold increase in units of enzyme per mg of dye. Similarly, poly(vinyl) alcohol microcapsules from [ 39 ] degrade 1.7 times more dye, despite an eightfold increase in units of enzyme per mg of dye. This confirms that our approach provides a higher catalytic performance than closely related encapsulates reported in the literature.…”