Metabolic Engineering of Corynebacterium glutamicum for the High-Level Production of Cadaverine That Can Be Used for the Synthesis of Biopolyamide 510

Fermentative production of cadaverine from renewable resources may support a sustainable biorefinery process to produce carbon-neutral nylons such as biopolyamide 510 (PA510). Cost-competitive production of cadaverine is a key factor in the successful commercialization of PA510. In this study, an integrated biological and chemical process involving cadaverine biosynthesis, purification, and its polymerization with sebacic acid was developed to produce bio-PA510. To stably express ldcC from Escherichia coli in an engineered Corynebacterium glutamicum PKC strain, an expired industrial l-lysine-producing strain, ldcC, was integrated into the chromosome of the C. glutamicum PKC strain by disrupting lysE and controlling its expression via a strong synthetic H30 promoter. Cadaverine was produced at a concentration of 103.78 g/L, the highest titer to date, from glucose by fed-batch culture of this engineered C. glutamgicum PKC strain. Fermentation-derived cadaverine was purified to polymer-grade biocadaverine with high purity (99%) by solvent extraction with chloroform and two-step distillation. Finally, biobased PA510 with good thermal properties (T_m 215 °C and T_c 158 °C) was produced by polymerization of purified cadaverine with sebacic acid. The hybrid biorefinery process combining biological and chemical processes demonstrated in this study is a useful platform for producing biobased chemicals and polymers.