One-Pot Chemobiocatalytic Production of 2,5-Bis(hydroxymethyl)furan and Its Diester from Biomass in Aqueous Media

Direct valorization of biomass into value-added chemicalsis attractiveyet challenging. Herein, we report a one-pot synthesis of 2,5-bis(hydroxymethyl)furan(BHMF) and its diacetate from inexpensive fructose and sugar syrupin the aqueous phase via sequential chemical dehydration, biocatalyticreduction, and esterification. A robust alcohol dehydrogenase from Escherichia coli (EcYjgB) was identifiedfor HMF reduction, with high catalytic efficiencies toward 5-hydroxymethylfurfural(HMF) (k (cat)/K (m), 1300 s(-1) mM(-1)) as well as NADPH(9700 s(-1) mM(-1)). Recombinant E. coli harboring EcYjgB (E. coli_EcYjgB) showed high tolerancetoward highly toxic and strongly inhibitory biobased furans, enablingsmooth reduction of 1 M HMF and 0.5 M furfural. Its practicality wasdemonstrated by gram-scale synthesis of BHMF with a 79% isolated yieldat approximately 126 g/L substrate loading. Biocatalytic process intensificationwas realized by improving cell membrane permeability using ethyl acetate,providing up to 15 g/L h BHMF productivity. A concurrent biocatalyticcascade for producing BHMF diacetate from HMF was constructed by combining E. coli_EcYjgB and Mycobacterium smegmatis acyltransferase (MsAcT) variant N94A, affording the desired product witha 93% yield in 1 h. Starting from crude HMF obtained via chemicaldehydration and organic solvent evaporation, BHMF and its diacetatewere produced with >99 and 88% yields, respectively. Finally, directsynthesis of these furan-based products from sugars was performedby chemobiocatalysis, without isolation of any intermediates, resultingin yields of up to 59% (relative to sugar). This work may pave theway for scalable production of furan-based chemicals from inexpensiverenewable biomass.