Highly Efficient Production of Menaquinone-7 from Glucose by Metabolically Engineered Escherichia coli
| Autor: | Xiaotong Zhong, Quanxiu Gao, Gaoyan Wang, XiaoJing Huo, Weifeng Liu, Baixue Lin, Jiezheng Liu, Hao Chen, Wei Yang, Jianzhong Huang, Yong Tao |
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| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
0303 health sciences Strain (chemistry) Biomedical Engineering Endogeny General Medicine medicine.disease_cause 01 natural sciences Biochemistry Genetics and Molecular Biology (miscellaneous) Metabolic engineering 03 medical and health sciences Titer chemistry.chemical_compound Biochemistry Biosynthesis chemistry 010608 biotechnology medicine Fermentation Escherichia coli Anaerobic exercise 030304 developmental biology |
| Zdroj: | ACS Synthetic Biology. 10:756-765 |
| ISSN: | 2161-5063 |
| Popis: | Menaquinone-7 (MK-7) possesses wide health and medical value, and the market demand for MK-7 has increased. Metabolic engineering for MK-7 production in Escherichia coli still remains challenging due to the characteristics of the competing quinone synthesis, and cells mainly synthesized menaquinones under anaerobic conditions. To increase the production of MK-7 in engineered E. coli strains under aerobic conditions, we divided the whole MK-7 biosynthetic pathway into three modules (MVA pathway, DHNA pathway, and MK-7 pathway) and systematically optimized each of them. First, by screening and enhancing Idi expression, the amounts of MK-7/DMK-7 increased significantly. Then, in the MK-7 pathway, by combinatorial overexpression of endogenous MenA and exogenous UbiE, and fine-tuning the expression of HepPPS, MenA, and UbiE, 70 μM MK-7 was achieved. Third, the DHNA synthetic pathway was enhanced, and 157 μM MK-7 was achieved. By the combinational metabolic engineering strategies and membrane engineering, an efficient metabolic engineered E. coli strain for MK-7 synthesis was developed, and 200 μM (129 mg/L) MK-7 was obtained in shake flask experiment, representing a 306-fold increase compared to the starting strain. In the scale-up fermentation, 2074 μM (1350 mg/L) MK-7 was achieved after 52 h fermentation with a productivity of 26 mg/L/h. This is the highest titer of MK-7 ever reported. This study offers an alternative method for MK-7 production from biorenewable feedstock (glucose) by engineered E. coli. The high titer of our process should make it a promising cost-effective resource for MK-7. |
| Databáze: | OpenAIRE |
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