Synthesis of biobased alcohols from biomass-derived aldehydes through the biocatalysis with E. coli KPADH in deep eutectic solvent ChCl:Glycerol-water

Alcohols can be extensively used in the production of fine chemicals, such as fuel additives, food supplements and pharmaceutical intermediates, which can be acquired by the reduction of biomass-derived aldehyde. In this study, the recombinant Escherichia coli KPADH was genetically constructed through the co-expression of alcohol dehydrogenase from Kluyveromyces polysporus and glucose dehydrogenase from Bacillus subtilis . Biomass-derived aldehydes were biologically converted into alcohols in a benign system. In deep eutectic solvent (DES) choline chloride:glycerol-H 2 O (choline chloride:glycerol, 10 wt %) containing E. coli KPADH cells (0.1 g/mL), HMF (50 mM), glucose (2 equivalents), and NAD + (0.1 μM/mM HMF), bioreduction of HMF into 2,5-bis(hydroxymethyl)furan was implemented, acquiring a high yield of 98.1 % within 8 h. Other biobased compounds, such as isovanillin, vanillin, p -hydroxybenzaldehyde, furfural, and benzaldehyde were also converted into their corresponding alcohols. According to the molecular docking results, HMF had the lowest CDOCKER energy value of -27.422 kcal/mol. It was found that HMF displayed strong binding affinity with E. coli KPADH, resulting in enhanced binding stability and superior catalytic reduction activity. This study demonstrated a green and highly effective biocatalytic method for the synthesis of biobased alcohols.