Design, Analysis, and Implementation of a Novel Biochemical Pathway for Ethylene Glycol Production in Clostridium autoethanogenum

The platform chemical ethylene glycol (EG) is used to manufacture various commodity chemicals of industrial importance, but largely remains synthesized from fossil fuels. Although several novel metabolic pathways have been reported for itsbioproduction in model organisms, none has been reported for gas-fermenting, non-model acetogenic chassis organisms. Here, wedescribe a novel, synthetic biochemical pathway to convert acetate into EG in the industrially important gas-fermenting acetogen,Clostridium autoethanogenum. We not only developed a computational workflow to design and analyze hundreds of novelbiochemical pathways for EG production but also demonstrated a successful pathway construction in the chosen host. The EGproduction was achieved using a two-plasmid system to bypass unfeasible expression levels and potential toxic enzymaticinteractions. Although only a yield of 0.029 g EG/g fructose was achieved and therefore requiring further strain engineering efforts tooptimize the designed strain, this work demonstrates an important proof-of-concept approach to computationally design andexperimentally implement fully synthetic metabolic pathways in a metabolically highly specific, non-model host organism.

Automated summary

This study presents a novel synthetic biochemical pathway to convert acetate into ethylene glycol (EG) in gas-fermenting acetogen Clostridium autoethanogenum. The research team developed a computational workflow to design and analyze numerous novel pathways for EG production, and successfully constructed the pathway in the chosen host organism. This work serves as an important proof-of-concept approach to computationally design and experimentally implement fully synthetic metabolic pathways.