Carbon-flux distribution in the central metabolic pathways of Corynebacterium glutamicum during growth on fructose Export

@article{citeulike:2393496, abstract = {Growth of Corynebacterium glutamicum on fructose was significantly less than that obtained on glucose, despite similar rates of substrate uptake. This was in part due to the production of overflow metabolites (dihydroxyacetone and lactate) but also to the increased production of CO2 during growth on fructose. These differences in carbon-metabolite accumulation are indicative of a different pattern of carbon-flux distribution through the central metabolic pathways. Growth on glucose has been previously shown to involve a high flux (> 50 \% of total glucose consumption) via the pentose pathway to generate anabolic reducing equivalents. NMR analysis of carbon-isotope distribution patterns of the glutamate pool after growth on 1-13C- or 6-13C-enriched fructose indicates that the contribution of the pentose pathway is significantly diminished during exponential growth on fructose with glycolysis being the predominant pathway (80 \% of total fructose consumption). The increased flux through glycolysis during growth on fructose is associated with an increased NADH/NAD+ ratio susceptible to inhibit both glyceraldehyde-3-phosphate dehydrogenase and pyruvate dehydrogenase, and provoking the overflow of metabolites derived from the substrates of these two enzymes. The biomass yield observed experimentally is higher than can be estimated from the apparent quantity of NADPH associated with the pentose pathway and the flux through isocitrate dehydrogenase, suggesting an additional reaction yielding NADPH. This may involve a modified tricarboxylic acid cycle involving malic enzyme, expressed to significantly higher levels during growth on fructose than on glucose, and a pyruvate carboxylating anaplerotic enzyme.}, author = {Dominguez, Helene and Rollin, Catherine and Guyonvarch, Armel and Jean and Bousquet, Muriel C. and Lindley, Nicholas D.}, citeulike-article-id = {2393496}, citeulike-linkout-0 = {http://www.blackwell-synergy.com/doi/abs/10.1046/j.1432-1327.1998.2540096.x}, citeulike-linkout-1 = {http://dx.doi.org/10.1046/j.1432-1327.1998.2540096.x}, doi = {10.1046/j.1432-1327.1998.2540096.x}, journal = {European Journal of Biochemistry}, keywords = {carbon, carbon\_flux, distribution, flux, fructose, growth, metabolic, metabolism, pathway}, number = {1}, pages = {96--102}, posted-at = {2008-02-18 11:27:16}, priority = {2}, title = {Carbon-flux distribution in the central metabolic pathways of Corynebacterium glutamicum during growth on fructose}, url = {http://dx.doi.org/10.1046/j.1432-1327.1998.2540096.x}, volume = {254}, year = {1998} }

TY - JOUR ID - citeulike:2393496 L3 - citeulike-article-id:2393496 N2 - Growth of Corynebacterium glutamicum on fructose was significantly less than that obtained on glucose, despite similar rates of substrate uptake. This was in part due to the production of overflow metabolites (dihydroxyacetone and lactate) but also to the increased production of CO2 during growth on fructose. These differences in carbon-metabolite accumulation are indicative of a different pattern of carbon-flux distribution through the central metabolic pathways. Growth on glucose has been previously shown to involve a high flux (> 50 % of total glucose consumption) via the pentose pathway to generate anabolic reducing equivalents. NMR analysis of carbon-isotope distribution patterns of the glutamate pool after growth on 1-13C- or 6-13C-enriched fructose indicates that the contribution of the pentose pathway is significantly diminished during exponential growth on fructose with glycolysis being the predominant pathway (80 % of total fructose consumption). The increased flux through glycolysis during growth on fructose is associated with an increased NADH/NAD+ ratio susceptible to inhibit both glyceraldehyde-3-phosphate dehydrogenase and pyruvate dehydrogenase, and provoking the overflow of metabolites derived from the substrates of these two enzymes. The biomass yield observed experimentally is higher than can be estimated from the apparent quantity of NADPH associated with the pentose pathway and the flux through isocitrate dehydrogenase, suggesting an additional reaction yielding NADPH. This may involve a modified tricarboxylic acid cycle involving malic enzyme, expressed to significantly higher levels during growth on fructose than on glucose, and a pyruvate carboxylating anaplerotic enzyme. IS - 1 JF - European Journal of Biochemistry EP - 102 TI - Carbon-flux distribution in the central metabolic pathways of Corynebacterium glutamicum during growth on fructose VL - 254 SP - 96 KW - carbon KW - carbon_flux KW - distribution KW - flux KW - fructose KW - growth KW - metabolic KW - metabolism KW - pathway AU - Dominguez, Helene AU - Rollin, Catherine AU - Guyonvarch, Armel AU - Jean AU - Bousquet, Muriel AU - Lindley, Nicholas PY - 1998/// UR - http://dx.doi.org/10.1046/j.1432-1327.1998.2540096.x ER -