Enzymatic Production of Glycerol from Glycolaldehyde and Formaldehyde

Abstract

Glycerol is a simple and important polyol in both biological and industrial field. To produce glycerol in an eco‐friendly manner, we established a one‐pot cascade reaction by fructose‐6‐phosphate aldolase (FSA) and aldehyde reductase (ALR) from formaldehyde (FALD) and its dimerized form glycolaldehyde (GALD) via L‐glyceraldehyde. For this, we characterized two FSAs at various conditions. Among them, FSA from Gilliamella apicola (GaFSA) has shown the higher L‐glyceraldehyde production activity in the phosphate buffer than the well‐known FSA from Escherichia coli (EcFSA) by more than 2 times. We also characterized two ALRs (xylose reductase from Candida tenuis; CtXR, the annotated DL‐glyceraldehyde reductase from Hypocrea jecorina; HjGLD) that specifically reduce L‐glyceraldehyde into glycerol. Bioproduction of glycerol from FALD and GALD was performed using GaFSA and CtXR, which produced ~8.8 mM glycerol from 25 mM of FALD and GALD (conversion yield of ~35%). This suggested that a simple process would help in designing a green production of glycerol from a wasteful one‐carbon chemicals.