Metabolic flux and robustness analysis of glycerol metabolism in Klebsiella pneumoniae
- 553 Downloads
The knowledge of the mechanism of flux distribution will benefit understanding cell physiology and regulation of metabolism. In this study, the measured fluxes obtained under steady-state conditions were used to estimate intracellular fluxes and identify the robustness of branch points of the anaerobic glycerol metabolism in Klebsiella pneumoniae for the production of 1,3-propanediol by metabolic flux analysis. The biomass concentration increased as NADH2/NAD+ decreased at low initial concentration and inversed at high initial glycerol concentration. The flux distribution revealed that the branch points of glycerol and dihydroxyacetonephosphate were rigid to the environmental conditions. However, the pyruvate and acetyl coenzyme A metabolisms gave cells the flexibility to regulate the energy and intermediate fluxes under various environmental conditions. Additionly, it was found that the formation rate of ethanol and the ratio of pyruvate dehydrogenase to pyruvate formate lyase appeared visible fluctuations at high glycerol uptake rate.
Keywords1,3-Propanediol Klebsiella pneumoniae Metabolic flux analysis Glycerol metabolism Metabolic network
This work was supported by the National Natural Science Foundation of China (No. 20576018) and the grant from the Major State Basic Research Development Program of China (973 Program) (No.2007CB714306).
- 4.Zeng AP, Biebl H (2002) Bulk chemicals from biotechnology: the case of 1,3-propanediol production and the new trends. Adv Biochem Eng Biotechnol 74:239–259Google Scholar
- 8.Forage RG, Lin EC (1982) DHA system mediating aerobic and anaerobic dissimilation of glycerol in Klebsiella pneumoniae NCIB 418. J Bacteriol 151:591–599Google Scholar
- 9.Tong IT, Liao HH, Cameron DC (1991) 1,3-Propanediol production by Escherichia coli expressing genes from the Klebsiella pneumoniae dha regulon. Appl Environ Microbiol 57:3541–3546Google Scholar
- 28.Guest J, Green J, Irvine A, Spiro S, (1996) The FNR modulon and FNR-regulated gene expression. In: Lin ECC, Lynch AS (eds) Regulation of gene expression in Escherichia coli. RG Landes Company, Austin pp 317–342Google Scholar
- 36.Daniel R, Boenigk R, Gottschalk G (1995) Purification of 1,3-propanediol dehydrogenase from Citrobacter freundii and cloning, sequencing, and overexpression of the corresponding gene in Escherichia coli. J Bacteriol 177:2151–2156Google Scholar
- 38.Menzel K (1999) Analyse der Stofffluesse und Metabolic Engineering der Glycerinvergaerung zu 1,3-Propandiol durch Klebsiella pneumoniae. Ph.D. thesis, German Research Center for Biotechnology (GBF), BraunschweigGoogle Scholar