Immobilization of Laccase in Alginate Beads

Abstract

The elimination or degradation of micropollutants from wastewater is becoming ever more important nowadays. Using oxidoreductase enzymes to treat different micropollutants seems a promising solution. However, the viability of the process is highly dependent on the availability and stability of the applied enzymes. In order to improve the stability and provide faster reaction rates, enzymes can be immobilized in various carriers. Properties such as simple production, easy retention and biodegradable carrier material are advantageous, e.g. entrapping laccase in alginate beads. This paper shows the results of the preparation and characterization of immobilized laccase entrapped in calcium alginate beads. The technique of adding a mixture of sodium alginate and laccase dropwise into calcium chloride has been applied, improved and standardized to produce laccase-containing beads of uniform size and activity. For the purpose of characterization, a widely used substrate, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, was used to evaluate the performance of the laccase-containing alginate beads. In addition to the characterization of the laccase-containing alginate beads, the enzyme kinetic constants (K M = 26.43 µM, Vmax = 0.23 µM/min) were determined. The reduction in the activity during storage has been described by a decay constant (0.26 d −1) that provides information concerning the design constraints of the process. Results will be used to test the method in terms of the removal of organic micropollutants in continuous systems.

Immobilization of partially purified laccase on polyhydroxyalkanoate (PHA) microbeads and its application in biodegradation of catechol

“…Earlier, the immobilization efficiencies of laccase immobilized on four distinct nanoparticles were 5.93%, 26.55%, 33.30% and 59.53% for C60‐, O‐MWNT‐, MWNT‐ and GO‐immobilized enzymes, respectively 41 . However, very high immobilization efficiencies of 89.22% and 98.20% were achieved using Ca‐alginate beads of sizes 2 and 3 mm, respectively, as matrix 42,43 . In another study, the optimal immobilization using activated carbon from pomegranate peels was obtained at 35 °C, pH 4.0 and enzyme concentration 2.5 mg mL −1 , which resulted in an immobilization yield of 69.8% 44 .…”

“…41 However, very high immobilization efficiencies of 89.22% and 98.20% were achieved using Ca-alginate beads of sizes 2 and 3 mm, respectively, as matrix. 42,43 In another study, the optimal immobilization using activated carbon from pomegranate peels was obtained at 35 °C, pH 4.0 and enzyme concentration 2.5 mg mL −1 , which resulted in an immobilization yield of 69.8%. 44 Likewise, the maximum immobilization yield of laccase immobilized on maple biochar was 64.23%, which was higher than that immobilized on spruce biochar.…”

Design and Optimization of Laccase Immobilization in Cellulose Acetate Microfiltration Membrane for Micropollutant Remediation

“…The synergic effect of adsorption and enzymatic transformation could enhance the efficiency of the overall removal process [11,12]. Similarly, entrapment of the laccase is beneficial due to its simplicity and the carrier matrix could also adsorb the pollutants and the reaction products as well [13]. However, entrapment may severely decrease the apparent activity of the catalysts by limiting substrate diffusion transfer to the enzyme [14].…”

Introduction of an Ambient 3D-Printable Hydrogel Ink to Fabricate an Enzyme-Immobilized Platform with Tunable Geometry for Heterogeneous Biocatalysis

“… Unlike other PEG-based bioinks, the low viscosity of the Pluronic F127 at low temperatures allows it to be homogeneously mixed with cells, biomolecules, or additional biopolymers. Sodium alginate (Alg), a naturally derived biocompatible and low-cost polymer popularly used as beads for enzyme and cell immobilization, − was proportionally introduced to make the chemically cross-linked F127 hydrogel with tunable hydrophilicity to promote efficient enzyme entrapment and function. Laccase, a multicopper enzyme, can degrade azo dyes and various toxic organic pollutants in plants, fungi, and bacteria.…”