| 초록 |
3-aminorpionic acid was produced using aspartase-catalyzed reaction based on fumaric-acid producing E. coli mutant (ΔiclR ΔfumA ΔfumB ΔfumC ΔptsG ΔlacI) strain. The C. glutamicum panD gene (encoding L-aspartate-α-decarboxylase) was overexpressed and the native promoter of the aspA gene was replaced with the strong trc promoter in fumaric acid producing E. coli mutant strain to produce 3-aminopropionic acid. Additionally, overexpression of the aspA and phosphoenolpyruvate carboxylase (ppc) genes, and the supplementation of ammonium sulfate in the medium allowed production of 3.49 g/L 3-AP. This was further increased to 3.94 g/L by optimizing the expression level of PPC, which was achieved by evaluating 12 different combinations of synthetic promoters and RBS sequences. Fed-batch culture of the final strain yielded 17.9 g/L 3-AP in 89 h, with an overall yield and productivity of 0.186 g 3-AP/g glucose and 0.200 g/L/h, respectively. (Development of systems metabolic engineering platform technologies for biorefineries; NRF-2012-C1AAA001-2012M1A2A2026556) funded by the Ministry of Education, Science and Technology) |
