Using E. coli to synthesize maleic acid

October 27, 2017

Success in bioproduction of a fossil fuel–derived polymer

RIKEN CSRS has succeeded in synthesizing maleic acid from biomass-derived materials using E. coli as a microbial catalyst. Maleic acid is an important general-purpose chemical used to produce various polymer compounds and pharmaceuticals.

Maleic anhydride, a dehydrogenated compound of maleic acid, can be converted to various unsaturated polyester resins and pharmaceutical intermediates. This valuable chemical has a global market in excess of 1.8 million tons per year, an order of magnitude higher than other useful dicarboxylic acids such as succinic acid (270,000 tons) and fumaric acid (90,000 tons). On the other hand, production of maleic acid depends on chemical synthesis. Bioprocesses that generate maleic acid from biomass resources without using fossil fuels are therefore needed in order to realize a low-carbon society.

Researchers succeeded in combining the polyketide synthesis pathway from actinomycetes and the aromatic compound–degrading pathway in bacteria to construct a novel maleic acid synthesis pathway in E. coli cells that synthesizes maleic acid directly from glucose, a component of biomass resources. By also optimizing the intracellular metabolic pathway, researchers succeeded in raising production more than 250 times over non-optimized strains to give a 37 percent yield.

If production rates and yields can be modified to accommodate large-scale culturing processes, a portion of chemical maleic acid production can be replaced with bioprocess production, thereby providing a great contribution to the realization of a low-carbon society.

Original article
Nature Communications doi:10.1038/s41467-017-01233-9
S. Noda, T. Shirai, Y. Mori, S. Oyama, A. Kondo,
"Engineering a synthetic pathway for maleate in Escherichia coli".
Shuhei Noda; Special Postdoctoral Researcher
Tomokazu Shirai; Deputy Team Leader
Akihiko Kondo; Team Leader
Cell Factory Research Team