Characterization, modification, and overexpression of 3-phosphoglycerate dehydrogenase in Corynebacterium glutamicum for enhancing l-serine production

• Published in: Annals of microbiology Vol. 65; no. 2; pp. 929 - 935
• Main Authors: Xu, Guoqiang, Jin, Xuexia, Guo, Wen, Dou, Wenfang, Zhang, Xiaomei, Xu, Zhenghong
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2015
• Subjects: Applied Microbiology; Biomedical and Life Sciences; Life Sciences; Medical Microbiology; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Mycology; Original Article; Feedback inhibition; Fermentation; Serine; PGDH
• ISSN: 1590-4261; 1869-2044
• DOI: 10.1007/s13213-014-0936-6

The direct fermentative production of l -serine from renewable biomass using Corynebacterium glutamicum is attracting increasing attention. In this study, wild-type C. glutamicum SYPS-062 produced up to 6.65 ± 0.23 g/L l -serine; to further improve l -serine production, the serA gene was cloned, and the C-terminal domain of 3-phosphoglycerate dehydrogenase (PGDH) from this strain was truncated. When expressed in Escherichia coli , the resultant mutein SerAΔ197 showed a specific PGDH activity of 1.092 ± 0.05 U/mg protein, representing a decrease of 25.87 % from that encoded by serA , and was no longer sensitive to high concentrations of l -serine. When serA Δ591 was overexpressed in C. glutamicum SYPS-062, the activity of PGDH in C. glutamicum pJC1- tac - serA Δ591 increased by 47.72 %, and the resultant strain C. glutamicum pJC1- tac - serA Δ591 could accumulate 7.69 ± 0.22 g/L l -serine. Furthermore, when serA Δ591 was overexpressed in C. glutamicum SYPS-062 ΔsdaA , the resultant strain could accumulate 8.84 ± 0.23 g/L l -serine at 102 h, and the yield of l -serine on cells (Y p/x) improved by 60 % when compared with that noted in the control. These results demonstrate that l -serine production in C. glutamicum SYPS-062 could be improved by overexpressing a C-terminal truncation of PGDH in combination with other genetic modifications.