Sustainable liquid supports for laccase immobilization and reuse: Degradation of dyes in aqueous biphasic systems
authors Ferreira, AM; Valente, AI; Castro, LS; Coutinho, JAP; Freire, MG; Tavares, APM
nationality International
author keywords aqueous biphasic systems; dye degradation; enzyme immobilization and reuse; ionic liquids; laccase; liquid support
abstract Novel liquid supports for enzyme immobilization and reuse based on aqueous biphasic systems (ABS) constituted by cholinium-based ionic liquids (ILs) and polymers for the degradation of dyes are here proposed. The biocatalytic reaction for dye decolorization using laccase occured in the biphasic medium, with the enzyme being supported in the IL-rich phase and the dye and degradation products being enriched in the polymer-rich phase. An initial screening of the laccase activity in aqueous solutions of ABS constituents, namely cholinium dihydrogen citrate ([Ch][DHC]), cholinium dihydrogen phosphate ([Ch][DHP]), cholinium acetate ([Ch][Acet]), polypropylene glycol 400 (PPG 400), polyethylene glycol 400 (PEG 400) and K2HPO4 was carried out. Compared to the buffered control, a relative laccase activity of up to 170%, 257%, and 530% was observed with PEG 400, [Ch][DHP], and [Ch][DHC], respectively. These ABS constituents were then investigated for the in situ enzymatic biodegradation of the Remazol Brilliant Blue R (RBBR) dye. At the optimized conditions, the ABS constituted by PPG 400 at 46 wt% and [Ch][DHC] at 16 wt% leads to the complete degradation of the RBBR dye, further maintaining the enzyme activity. This ABS also allows an easy immobilization, recovery, and reuse of the biocatalyst for six consecutive reaction cycles, achieving a degradation yield of the dye of 96% in the last cycle. In summary, if properly designed, high enzymatic activities and reaction yields are obtained with ABS as liquid supports, while simultaneously overcoming the safety and environmental concerns of conventional organic solvents used in liquid-liquid heterogeneous reactions, thus representing more sustainable biocatalytic processes.
publisher WILEY
issn 0006-3592
isbn 1097-0290
year published 2021
volume 118
issue 7
beginning page 2514
ending page 2523
digital object identifier (doi) 10.1002/bit.27764
web of science category 10
subject category Biotechnology & Applied Microbiology
unique article identifier WOS:000637676200001