Development of Metabolically Engineered Corynebacterium glutamicum for Enhanced Production of Cadaverine and Its Use for the Synthesis of Bio-Polyamide 510

Lysine decarboxylases (LDCs) from Escherichia coli, Lactobacillus saerimneri, Streptomyces coelicolor, Selemonas ruminantium, Hafnia alvei, and Vibrio vulnificus were examined for their ability to enhance the fermentative production of cadaverine in Corynebacterium glutamcium. Among these LDCs, the plasmid-based expression of the H. alvei LDC gene (ldcC_Ha) under strong promoters (P_H30, P_H36) produced high concentrations of cadaverine (11.4-11.5 g/L), which is similar to 12.5 g/L of cadaverine produced by the plasmid-based expression of the E. coli LDC gene (ldcC_Ec) by the P_H30 promoter in our previous report. The production of cadaverine in batch (30.8 g/L) and fed-batch (93.7 g/L) fermentation cultures using recombinant strain Corynebacterium glutamicum H30HaLDC expressing plasmid-borne ldcC_Ha under control of the P_H30 promoter was 18 and 14% higher than that obtained using C. glutamicum P-H30 expressing plasmid-borne ldcC_Ec under control of the P_H30 promoter, in which production was only 26 and 82.2 g/L in batch and fed-batch cultures, respectively. Finally, C. glutamicum GH30HaLDC was constructed by integration of ldcC_Ha into C. glutamicum PKC at the lysE site. C. glutamicum GH30HaLDC produced 125 g/L of cadaverine in fed-batch culture, which was 20% higher than the cadaverine production of 104 g/L by C. glutamicum G-H30 in our previous report. Cadaverine produced by fed-batch culture of C. glutamicum GH30HaLDC was purified and used for the synthesis of bio-based polyamide PA510 by copolymerization with sebacic acid. Synthesized PA510 showed thermal and material properties comparable to those of chemical-based PA510.