One-pot two-step biocatalytic upgrading of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid (FDCA) through a sequential oxidation process

2, 5-furandicarboxylic acid (FDCA) is a versatile bio-based building block that can be used for the synthesis of degradable polymers. Recently, developing green and sustainable catalytic processes for producing FDCA from renewable platform chemical molecules has attracted continuing attention. In this study, we proposed a green and sustainable one-pot, two-step biocatalytic process for the sequential oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to form FDCA with good yield and excellent selectivity. The initial step involves the oxidation of HMF to 2, 5-diformylfuran (DFF) and 5-formyl-2-furancarboxylic acid (FFCA) catalyzed by recombinant E. coli cells expressing a 5-hydroxymethylfurfural oxidase. The second step is to convert DFF and FFCA into FDCA final product via aldehyde oxidation reaction catalyzed by Deinococcus wulumuqiensis R12 whole cells. Combining the two different whole-cell biocatalysts, 180 mM of HMF could be easily converted into FDCA with a yield of 99% under optimized reaction conditions. This study offers an efficient and sustainable approach for the valorization of biomass-based HMF to form value-added FDCA.