title: [Effect of adding intermediate metabolites on succinate production by Actinobacillus succinogenes].
abstract: We investigated the effect of adding intermediate metabolites on cell growth and succinate production. The yield of succinic acid achieved to the highest when 0.5 g/L phosphoenolpyruvic acid (PEP) was added. According to the metabolic network of Actinobaccilus succinogenes NJ113, the metabolic flux was calculated by metabolic flux analysis. The ratio of hexose monophosphate pathway to glycolytic pathway increased from 39.4:60.3 to 76.8:22.6 after adding 0.5 g/L PEP, thus the reducing power was better balanced. The flux of PEP to oxaloacetate was 23.8% higher, which made the succinic acid flux improve from 99.8 mmol/(g DCW x h) to 124.4 mmol/(g DCW x h) and the flux of acetic acid and formic acid decreased by 22.9% and 15.4%, respectively. The key enzyme activity analysis showed that the specific activity of PEP carboxykinase reached to 1910 U/mg with 0.5 g/L PEP addition, which was 74.7% higher than the control; and the specific activity of pyruvate kinase decreased by 67.5%. Finally, the concentration of succinic acid was 29.1 g/L with the yield of 76.2%.
authors.affiliation: State Key Laboratory of Materials-oriented Chemical Engineering, College of Life Science and Pharmacy, Nanjing University of Technology, Nanjing 210009, China.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Huang
authors.forename: Min
authors.initials: M
authors.lastname: Jiang
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zheng
authors.forename: Zhuona
authors.initials: Z
authors.lastname: Yang
authors.forename: Xiaojiang
authors.initials: X
authors.lastname: Fang
authors.forename: Guizi
authors.initials: G
authors.lastname: Ye
mesh_terms: D000188:Actinobacillus / Q000378:metabolism*; D000693:Anaerobiosis; D003470:Culture Media; D046508:Culture Techniques / Q000379:methods*; D005285:Fermentation; D017866:Phosphotransferases (Paired Acceptors) / Q000378:metabolism*; D019802:Succinic Acid / Q000378:metabolism*
chemical_list: D003470:Culture Media; D019802:Succinic Acid; D017866:Phosphotransferases (Paired Acceptors); C022509:pyruvate, water dikinase