Beschreibung
The lignocellulosic biomass degradation process can likely be improved by incorporating the laccase - mediator (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS)) system for lignin depolymerization. Ionic liquids such as [EMIM][EtSO4] and [EMIM][Ac] improve lignin solubility and enzymatic access to lignin. However, enzyme activity decreases in ionic liquids. The kinetics of the laccase - mediator reaction was experimentally investigated and mechanistically modeled in buffer and ionic liquid co-solvent solutions. Laccase in buffer solution had a higher activity compared to laccase in 5, 15, and 30% (v/v) [EMIM][EtSO4] and [EMIM][Ac] in water co-solvent. However, ionic liquids at lower concentrations helped to stabilize laccase activity over time. Correlations were made between ionic liquid concentrations and enzyme stability over time, reaction kinetics of laccase with the mediator, and of the mediator - substrate reaction. Using these correlations, the reaction kinetics of the entire laccase - mediator system was evaluated at different ionic liquid concentrations. Generally, ionic liquids at lower concentrations facilitate the reaction rate of the substrate with the mediator and improve laccase stability over time, potentially leading to higher product formation and total turnover number. Although ionic liquids at lower concentrations may have some beneficial effects on the laccase - mediator system, enzyme activity is decreased, making the process less efficient and economically viable. By investigating the reaction kinetics of the laccase - mediator system in buffer and ionic liquids optimal concentrations of enzyme, mediator, substrate, and ionic liquids can be determined for optimal product formation.
Herstellerkennzeichnung:
Shaker Verlag GmbH
Am Langen Graben 15a
52353 Düren
DE
E-Mail: info@shaker.de
