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

Abstract

The industrial and environmental applications of laccase, especially in wastewater treatment, have gained focus in recent years. Therefore, developing the proper laccase immobilization techniques, which could improve the stability of the enzymes and simplify the required downstream processes, is needed. A novel two-step immobilization process was developed, resulting in cross-linked enzyme aggregates (CLEA) in the pores of the membrane. Laccase adsorption on a biodegradable cellulose acetate microfiltration membrane along with cross-linking was investigated to maximize the enzyme load and immobilization efficiency. The optimization was done regarding the: pH, temperature, enzyme concentration, adsorption time, cross-linker concentration, and temperature. It was concluded that the highest immobilization efficiency (76%) could be achieved in acidic buffers at 29 ∘C with high surface activity (1174 U·m−2) at the cost of partial denaturation and membrane fouling. The membrane was successfully utilized for the enzymatic treatment of diclofenac, and 58% removal efficiency was achieved. The results indicated that cellulose acetate is a suitable carrier for adsorption-based immobilization of laccase for the potential for environmental utilisation.

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

“…In a recent study, an immobilization efficiency of 76% was achieved in acidic buffer at 29 °C with laccase immobilized on cellulose acetate microfiltration membrane. 40 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.…”

“…Partially purified laccase immobilized on PHA microbeads demonstrated immobilization efficiency of 77.44%. In a recent study, an immobilization efficiency of 76% was achieved in acidic buffer at 29 °C with laccase immobilized on cellulose acetate microfiltration membrane 40 . 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 .…”

Opting for Polyamines with Specific Structural Traits as a Strategy to Boost Performance of Enzymatic Membrane Reactors

“…Table S2 in SI, S10 provides a comparison of the most recent modification and fabrication methods for improvement of EMR characteristics [46][47][48][49]. Although the mentioned studies may indicate more significant advancements of enzyme and/or membrane performance, the main purpose of this study was to map the pathway towards the desired polyamine chemistry rather than offer a ready solution for a large-scale application.…”

Cellulose Acetate-Based Materials for Water Treatment in the Context of Circular Economy

“…Composite cellulose acetate/layered double hydroxide (LDH) membranes were also successfully used for State-of-the-art solutions for the removal of organic micropollutants involve enzymatic degradation techniques. For example, the immobilization of laccase in the structure of a cellulose acetate membrane resulted in high removal efficiency (58%) of diclofenac and also the total degradation of the retained drug retained [109]. These materials are, however, limited by the very presence of the enzyme in the membrane structure.…”