title: Improving the secretion of cadaverine in Corynebacterium glutamicum by cadaverine-lysine antiporter.
abstract: Cadaverine (1,5-pentanediamine, diaminopentane), the desired raw material of bio-polyamides, is an important industrial chemical with a wide range of applications. Biosynthesis of cadaverine in Corynebacterium glutamicum has been a competitive way in place of petroleum-based chemical synthesis method. To date, the cadaverine exporter has not been found in C. glutamicum. In order to improve cadaverine secretion, the cadaverine-lysine antiporter CadB from Escherichia coli was studied in C. glutamicum. Fusion expression of cadB and green fluorescent protein (GFP) gene confirmed that CadB could express in the cell membrane of C. glutamicum. Co-expression of cadB and ldc from Hafnia alvei in C. glutamicum showed that the cadaverine secretion rate increased by 22 % and the yield of total cadaverine and extracellular cadaverine increased by 30 and 73 %, respectively. Moreover, the recombinant strain cultured at acid and neutral pH separately hardly had any difference in cadaverine concentrations. These results suggested that CadB could be expressed in the cell membrane of C. glutamicum and that recombinant CadB could improve cadaverine secretion and the yield of cadaverine. Moreover, the pH value did not affect the function of recombinant CadB. These results may be a promising metabolic engineering strategy for improving the yield of the desired product by enhancing its export out of the cell.
authors: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, National Engineering Laboratory for Industrial Enzymes, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin, People's Republic of China.
authors: Ming
authors: M
authors: Li
authors: Dongxia
authors: D
authors: Li
authors: Yunyan
authors: Y
authors: Huang
authors: Meng
authors: M
authors: Liu
authors: Hongxin
authors: H
authors: Wang
authors: Qi
authors: Q
authors: Tang
authors: Fuping
authors: F
authors: Lu
mesh_terms: D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism*; D017920:Antiporters / Q000235:genetics / Q000378:metabolism*; D002103:Cadaverine / Q000096:biosynthesis / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D060847:Metabolic Engineering
chemical_list: D026905:Amino Acid Transport Systems; D017920:Antiporters; C490242:CadB protein, E Coli; D029968:Escherichia coli Proteins; D002103:Cadaverine