Home | Publications
5-Hydroxymethylfurfural conversion by fungal aryl-alcohol oxidase and unspecific peroxygenase
Carro J, Ferreira P, Rodríguez L, Prieto A, Serrano A, Balcells B, Ardá A, Jiménez-Barbero J, Gutiérrez A, Ullrich R, Hofrichter M, Martínez AT

FEBS J., 282: 3218-3229

Oxidative conversion of 5-hydroxymethylfurfural (HMF) is of biotechnological interest for the production of renewable (lignocellulose based) platform chemicals, such as 2,5-furandicarboxylic acid (FDCA). The ability of fungal aryl-alcohol oxidase (AAO) to oxidize HMF is reported here for the first time, resulting in a nearly complete conversion into 2,5-formylfurancarboxylic acid (FFCA) in a few hours. The reaction starts by alcohol oxidation yielding 2,5-diformylfuran (DFF) that is rapidly converted into FFCA by carbonyl oxidation, most probably without leaving the enzyme active site. This agrees with the similar catalytic efficiency of the enzyme oxidizing HMF and DFF and its very low activity on 2,5-hydroxymethylfurancarboxylic acid (that could not be detected by GC-MS). However, AAO was found to be unable to directly oxidize the carbonyl group in FFCA, and only modest amounts of FDCA are formed from HMF (most probably by chemical oxidation of FFCA by the H2 O2 previously generated by AAO). Since aldehyde oxidation by AAO proceeds via the corresponding geminal diols (aldehyde hydrates), the different carbonyl oxidation rates could be related to the low hydration degree of FFCA compared with DFF. The conversion of HMF was completed by introducing a fungal unspecific heme peroxygenase that uses the H2O2 generated by AAO to transform FFCA into FDCA, albeit more slowly than the previous AAO reactions. By adding this peroxygenase when FFCA production by AAO has been completed, transformation of HMF into FDCA can be attained in a reaction cascade where O2 is the only cosubstrate needed, and water the only by-product formed. This article is protected by copyright. All rights reserved.

External link