Heterologous construction of the 3-HP carbon fixation pathway with mesaconate as an indicator in S. cerevisiae
The reconstruction of the CO2 fixation pathway in the traditional microbial cell factories enables CO2 recycle, contributing to the reduction of the green-house gas emission. The 3-Hydroxypropionic acid (3-HP) pathway is one of the six known natural carbon fixation pathways. Mesaconate is a high value-added derivative in the 3-HP pathway, and can be used as a co-monomer to produce fire-retardant materials and hydrogels. Most of the intermediates in the 3-HP pathway are acyl-CoAs, which are difficult to quantify in cell extracts. Mesaconate is produced from mesaconyl-C1-CoA, the intermediate metabolite in the 3-HP pathway. In this study, mesaconate was used as an indicator compound to assess the efficiency of reactions from acetyl-CoA to mesaconyl-C1-CoA, which facilitates the construction and optimization of the 3-HP sub-pathway in S. cerevisiae with the use of glucose or ethanol as the substrate.