Converting biomass into high value-added compounds has attracted great attention for solving fossil fuel consumption and global warming. 5-Hydroxymethylfurfural (HMF) has been considered as a versatile biomass-derived building block that can be used to synthesize a variety of sustainable fuels and chemicals. Among these derivatives, 2,5-furandicarboxylic acid (FDCA) is a desirable alternative to petroleum-derived terephthalic acid for the synthesis of biodegradable polyesters. Herein, to fully understand the current development of the catalytic conversion of biomass to FDCA, a comprehensive review of the catalytic conversion of cellulose biomass to HMF and the oxidation of HMF to FDCA is presented. Moreover, future research directions and general trends of using biomass for FDCA production are also proposed.

2,5-Furandicarboxylic acid (FDCA) is an important renewable biotechnological building block because it serves as an environmentally friendly substitute for terephthalic acid in the production of polyesters. Currently, FDCA is produced mainly via chemical oxidation, which can cause severe environmental pollution. In this study, we developed an environmentally friendly process for the production of FDCA from 5-hydroxymethyl furfural (5-HMF) using a newly isolated strain, Raoultella ornithinolytica BF60. First, R. ornithinolytica BF60 was identified by screening and was isolated. Its maximal FDCA titer was 7.9 g/liter, and the maximal molar conversion ratio of 5-HMF to FDCA was 51.0% (mol/mol) under optimal conditions (100 mM 5-HMF, 45 g/liter whole-cell biocatalyst, 30°C, and 50 mM phosphate buffer [pH 8.0]). Next, dcaD , encoding dicarboxylic acid decarboxylase, was mutated to block FDCA degradation to furoic acid, thus increasing FDCA production to 9.2 g/liter. Subsequently, aldR , encoding aldehyde reductase, was mutated to prevent the catabolism of 5-HMF to HMF alcohol, further increasing the FDCA titer, to 11.3 g/liter. Finally, the gene encoding aldehyde dehydrogenase 1 was overexpressed. The FDCA titer increased to 13.9 g/liter, 1.7 times that of the wild-type strain, and the molar conversion ratio increased to 89.0%. IMPORTANCE In this work, we developed an ecofriendly bioprocess for green production of FDCA in engineered R. ornithinolytica . This report provides a starting point for further metabolic engineering aimed at a process for industrial production of FDCA using R. ornithinolytica .