Engineering RuBisCO-based shunt for improved cadaverine production in Escherichia coli

The process of biological fermentation is often accompanied by the release of CO₂, resulting in low yield and environmental pollution. Refixing CO₂ to the product synthesis pathway is an attractive approach to improve the product yield. Cadaverine is an important diamine used for the synthesis of bio-based polyurethane or polyamide. Here, aiming to increase its final production, a RuBisCO-based shunt consisting of the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and phosphoribulate kinase (PRK) was expressed in cadaverine-producing E. coli. This shunt was calculated capable of increasing the maximum theoretical cadaverine yield based on flux model analysis. When a functional RuBisCO-based shunt was established and optimized in E. coli, the cadaverine production and yield of the final engineered strain reached the highest level, which were 84.1 g/L and 0.37 g/g _Glucose, respectively. Thus, the design of in situ CO₂ fixation provides a green and efficient industrial production process.