caa a22 4500 605499063 CHVBK 20210128100549.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s00253-015-6391-x doi (NATIONALLICENCE)springer-10.1007/s00253-015-6391-x Enhanced production of polysialic acid by metabolic engineering of Escherichia coli [Elektronische Daten] [Fang Chen, Yong Tao, Cheng Jin, Yang Xu, Bai-Xue Lin] A number of reports have described the production of polysialic acid (PSA), focusing on the fermentation and purification of PSA. However, little work has been done to strengthen the synthetic pathway of PSA to improve PSA production. In this study, an efficient process for enhanced production of PSA using a recombinant Escherichia coli strain was developed. To improve the PSA production efficiency, the key enzymes of PSA synthetic pathway were overexpressed separately or in combination, including N-acetylneuraminate (Neu5Ac) 7-O(or 9-O)-acetyltransferase (NeuD), CMP-Neu5Ac synthetase (NeuA), and alpha-Neu5Ac alpha-2,8-sialyltransferase (NeuS). The PSA production was significantly improved by coexpression of NeuD and NeuA. In terms of the efficiency, NeuD was considered as the most important factor. Secondly, the competing pathway of intermediate Neu5Ac was blocked by nanA deletion. The efficient PSA-producing strain E. coli SA9ΔnanA/pDB1S-DA was constructed, and 16.15 ± 1.45g/L PSA was obtained in the fed-batch culture. The production of PSA by engineered strain was increased by 85% compared to the original strain. These results provide evidence for improvement of PSA production by regulation of the PSA biosynthetic pathway. The high productivity of our process should make it a promising cost-effective resource for PSA. Springer-Verlag Berlin Heidelberg, 2015 Polysialic acid nationallicence Escherichia coli nationallicence Metabolic engineering nationallicence Fed-batch fermentation nationallicence Chen Fang CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, 100101, Beijing, People's Republic of China aut Tao Yong CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, 100101, Beijing, People's Republic of China aut Jin Cheng The State Key Laboratory of Mycology (SKLM), Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, People's Republic of China aut Xu Yang Sino-Germany Joint Research Institute, Nanchang University, 330047, Nanchang, Jiangxi, China aut Lin Bai-Xue CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, 100101, Beijing, People's Republic of China aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/6(2015-03-01), 2603-2611 0175-7598 99:6<2603 2015 99 253 https://doi.org/10.1007/s00253-015-6391-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6391-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chen Fang CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, 100101, Beijing, People's Republic of China aut NATIONALLICENCE 700 1- Tao Yong CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, 100101, Beijing, People's Republic of China aut NATIONALLICENCE 700 1- Jin Cheng The State Key Laboratory of Mycology (SKLM), Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, People's Republic of China aut NATIONALLICENCE 700 1- Xu Yang Sino-Germany Joint Research Institute, Nanchang University, 330047, Nanchang, Jiangxi, China aut NATIONALLICENCE 700 1- Lin Bai-Xue CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, 100101, Beijing, People's Republic of China aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/6(2015-03-01), 2603-2611 0175-7598 99:6<2603 2015 99 253