Researchers have successfully synthesized fumarate (fumaric acid), a raw material for unsaturated polyester resin, by combining carbon dioxide (CO2) with pyruvate (derived from biomass), using two biocatalysts: malate dehydrogenase and fumarase. Fumarate is currently used to make biodegradable plastic like polybutylene succinate from petroleum. However, this research has enabled the synthesis of fumarate without petroleum, consuming only CO2 and biomass-derived pyruvate.