Laccases from Pleurotus ostreatus applied to the oxidation of furfuryl alcohol for the synthesis of key compounds for polymer industry.

Laccases are oxidative enzymes with high synthetic potential. In this work, we prove their value in biocatalysis through the green and selective oxidation of furfuryl alcohol into furfural with the aid of mediators. The influence of different parameters such as pH, enzyme/mediator composition, buffer type, cosolvent tolerance and reaction times were deeply investigated. Under the optimal conditions, 20 mol% of TEMPO as mediator, and 5.8 U mL-1 of laccases POXC and POXA1b from Pleurotus ostreatus allowed to achieve quantitative production of furfural after 16 h. POXC laccase stood out for its ability to catalyze the reaction at pH 6.5, meanwhile POXA1b highlighted for its high stability. Furfural conversions reached excellent values (95%) after 72 h using only 5 mol% of TEMPO at 100 mM. Furthermore, furfuryl alcohol bioamination was successfully achieved employing the amine transaminase from Chromobacterium violaceum, providing furfuryl amine, a key compound for polymer industry, through a one-pot sequential approach.