Monday, July 25, 2011
Grand Ballroom, 5th fl (Sheraton New Orleans)
A five carbon linear chain diamine, cadaverine (1,5-diaminopentane), is an important platform chemical having many applications in chemical industry. Bio-based production of cadaverine from renewable feedstock is a promising and sustainable alternative to the petroleum-based chemical synthesis. Here, we report development of a metabolically engineered strain of Escherichia coli that overproduces cadaverine in glucose mineral salts medium. First, cadaverine degradation and utilization pathways were inactivated. Next, L-lysine decarboxylase, which converts L-lysine directly to cadaverine, was amplified by plasmid-based overexpression of the cadA gene under the strong tac promoter. Furthermore, the L-lysine biosynthetic pool was increased by the overexpression of the dapA gene encoding dihydrodipicolinate synthase through the replacement of the native promoter with the strong trc promoter in the genome. The final engineered strain was able to produce 9.61 g /L of cadaverine with a productivity of 0.32 g/ L/ h by fed-batch cultivation. The strategy reported here should be useful for the bio-based production of cadaverine from renewable resources. [This work was supported by the Korean Systems Biology Research Project (20110002149) of the Ministry of Education, Science and Technology (MEST) through the National Research Foundation of Korea. Further support by the World Class University Program (R32-2008-000-10142-0) through the National Research Foundation of Korea funded by the MEST is appreciated.]