Effective biosynthesis of 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural via a bi-enzymatic cascade system using bacterial laccase and fungal alcohol oxidase

Background As a cost-effective and eco-friendly approach, biocatalysis has great potential for the transformation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA). However, the compatibility of each enzyme in the cascade reaction limits the transformation efficiency of HMF to FDCA. Results Coupled with an alcohol oxidase from Colletotrichum gloeosporioides ( Cgl AlcOx), this study aims to study the potential of bacterial laccase from Bacillus pumilus ( Bp Lac) in an enzymatic cascade for 2,5-furandicarboxylic acid (FDCA) biosynthesis from 5-hydroxymethylfurfural (HMF). Bp Lac showed 100% selectivity for HMF oxidation and generated 5-hydroxymethyl-2-furancarboxylic acid (HMFCA). Cgl AlcOx was capable of oxidizing HMFCA to 2-formyl-5-furancarboxylic acid (FFCA). Both Bp Lac and Cgl AlcOx could oxidize FFCA to FDCA. At the 5 mM scale, a complete transformation of HMF with a 97.5% yield of FDCA was achieved by coupling Bp Lac with Cgl AlcOx in the cascade reaction. The FDCA productivity in the reaction was 5.3 mg/L/h. Notably, Bp Lac could alleviate the inhibitory effect of FFCA on Cgl AlcOx activity and boost the transformation efficiency of HMF to FDCA. Moreover, the reaction was scaled up to 40 times the volume, and FDCA titer reached 2.6 mM with a yield of 58.77% at 168 h. Conclusions This work provides a candidate and novel insight for better design of an enzymatic cascade in FDCA production.