2,5-Furandimethanol (BHMF) is an important biobased chemical, which can be widely used in the production of fuels, drugs, and polymers. However, BHMF production mainly relies on chemical methods for reduction of 5-hydroxymethylfurfural (HMF), which suffer from low selectivity and environmental concerns. In this study, alcohol dehydrogenase AdhP from Escherichia coli was screened and engineered at residue W84 to generate the 84A mutant, exhibiting a 1.3-fold increase in the catalytic reduction rate compared with the wild-type AdhP at pH 7.0 and 35 °C. Coupling W84A with glucose dehydrogenase (GDH) created the recombinant E. coli AD84 whole-cell catalyst, which might efficiently transform high-titer HMF (1 M) into BHMF (118 g/L) in a yield of 93.3% under 30 °C and pH 7.0 in 6 h. Furthermore, a chemoenzymatic one-pot approach was developed to transform waste bread into BHMF, achieving the valorization of food waste through tandem catalysis with a deep eutectic solvent (DES) chemocatalyst and whole-cell biocatalyst. In a deep eutectic solvent (Betaine:Malic acid:Glycerol)-H2O (10:90, wt/wt) system, waste bread (20.0 g/L) was transformed to 5-HMF at 190 °C for 15 min, with a yield of 26%. Subsequently, E. coli AD84 cells catalyzed the bioreduction of waste bread-derived HMF into BHMF, acquiring a yield of 97% (0.26 g of BHMF/g of bread waste). This work constructed a robust reductase biocatalyst for efficiently transforming high titer of HMF and waste bread-derived HMF into BHMF, providing a sustainable approach for food waste valorization.
Li et al. (Fri,) studied this question.