scholarly journals Correlation between TCA cycle flux and glucose uptake rate during respiro-fermentative growth of Saccharomyces cerevisiae

Microbiology ◽  
2009 ◽  
Vol 155 (12) ◽  
pp. 3827-3837 ◽  
Author(s):  
Jan Heyland ◽  
Jianan Fu ◽  
Lars M. Blank
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Uptake ◽  
Production Rate ◽  
Environmental Conditions ◽  
Glucose Repression ◽  
Single Gene ◽  
Tca Cycle ◽  
Acetate Production ◽  
The Tca Cycle ◽  
Uptake Rates

Glucose repression of the tricarboxylic acid (TCA) cycle in Saccharomyces cerevisiae was investigated under different environmental conditions using 13C-tracer experiments. Real-time quantification of the volatile metabolites ethanol and CO2 allowed accurate carbon balancing. In all experiments with the wild-type, a strong correlation between the rates of growth and glucose uptake was observed, indicating a constant yield of biomass. In contrast, glycerol and acetate production rates were less dependent on the rate of glucose uptake, but were affected by environmental conditions. The glycerol production rate was highest during growth in high-osmolarity medium (2.9 mmol g−1 h−1), while the highest acetate production rate of 2.1 mmol g−1 h−1 was observed in alkaline medium of pH 6.9. Under standard growth conditions (25 g glucose l−1 , pH 5.0, 30 °C) S. cerevisiae had low fluxes through the pentose phosphate pathway and the TCA cycle. A significant increase in TCA cycle activity from 0.03 mmol g−1 h−1 to about 1.7 mmol g−1 h−1 was observed when S. cerevisiae grew more slowly as a result of environmental perturbations, including unfavourable pH values and sodium chloride stress. Compared to experiments with high glucose uptake rates, the ratio of CO2 to ethanol increased more than 50 %, indicating an increase in flux through the TCA cycle. Although glycolysis and the ethanol production pathway still exhibited the highest fluxes, the net flux through the TCA cycle increased significantly with decreasing glucose uptake rates. Results from experiments with single gene deletion mutants partially impaired in glucose repression (hxk2, grr1) indicated that the rate of glucose uptake correlates with this increase in TCA cycle flux. These findings are discussed in the context of regulation of glucose repression.

TCA cycle activity in Saccharomyces cerevisiae is a function of the environmentally determined specific growth and glucose uptake rates

Microbiology ◽  
2004 ◽  
Vol 150 (4) ◽  
pp. 1085-1093 ◽  
Author(s):  
Lars M. Blank ◽  
Uwe Sauer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Glucose Uptake ◽  
Environmental Conditions ◽  
Specific Growth ◽  
Tca Cycle ◽  
Glucose Sensing ◽  
The Tca Cycle ◽  
Uptake Rates ◽  
Wide Range

Metabolic responses of Saccharomyces cerevisiae to different physical and chemical environmental conditions were investigated in glucose batch culture by GC-MS-detected mass isotopomer distributions in proteinogenic amino acids from 13C-labelling experiments. For this purpose, GC-MS-based metabolic flux ratio analysis was extended from bacteria to the compartmentalized metabolism of S. cerevisiae. Generally, S. cerevisiae was shown to have low catabolic fluxes through the pentose phosphate pathway and the tricarboxylic acid (TCA) cycle. Notably, respiratory TCA cycle fluxes exhibited a strong correlation with the maximum specific growth rate that was attained under different environmental conditions, including a wide range of pH, osmolarity, decoupler and salt concentrations, but not temperature. At pH values of 4·0 to 6·0 with near-maximum growth rates, the TCA cycle operated as a bifurcated pathway to fulfil exclusively biosynthetic functions. Increasing or decreasing the pH beyond this physiologically optimal range, however, reduced growth and glucose uptake rates but increased the ‘cyclic’ respiratory mode of TCA cycle operation for catabolism. Thus, the results indicate that glucose repression of the TCA cycle is regulated by the rates of growth or glucose uptake, or signals derived from these. While sensing of extracellular glucose concentrations has a general influence on the in vivo TCA cycle activity, the growth-rate-dependent increase in respiratory TCA cycle activity was independent of glucose sensing.

scholarly journals Suppressors reveal two classes of glucose repression genes in the yeast Saccharomyces cerevisiae.

Genetics ◽  
1994 ◽  
Vol 136 (4) ◽  
pp. 1271-1278 ◽  
Author(s):  
J R Erickson ◽  
M Johnston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Repression ◽  
Single Gene ◽  
The Other ◽  
Gene Products ◽  
Yeast Saccharomyces Cerevisiae ◽  
Similar Point ◽  
Normal Glucose ◽  
Gal Genes ◽  
Extragenic Suppressors

Abstract We selected and analyzed extragenic suppressors of mutations in four genes--GRR1, REG1, GAL82 and GAL83-required for glucose repression of the GAL genes in the yeast Saccharomyces cerevisiae. The suppressors restore normal or nearly normal glucose repression of GAL1 expression in these glucose repression mutants. Tests of the ability of each suppressor to cross-suppress mutations in the other glucose repression genes revealed two groups of mutually cross-suppressed genes: (1) REG1, GAL82 and GAL83 and (2) GRR1. Mutations of a single gene, SRG1, were found as suppressors of reg1, GAL83-2000 and GAL82-1, suggesting that these three gene products act at a similar point in the glucose repression pathway. Mutations in SRG1 do not cross-suppress grr1 or hxk2 mutations. Conversely, suppressors of grr1 (rgt1) do not cross-suppress any other glucose repression mutation tested. These results, together with what was previously known about these genes, lead us to propose a model for glucose repression in which Grr1p acts early in the glucose repression pathway, perhaps affecting the generation of the signal for glucose repression. We suggest that Reg1p, Gal82p and Gal83p act after the step(s) executed by Grr1p, possibly transmitting the signal for repression to the Snf1p protein kinase.

Null mutations in the SNF3 gene of Saccharomyces cerevisiae cause a different phenotype than do previously isolated missense mutations

1986 ◽  
Vol 6 (11) ◽  
pp. 3569-3574
Author(s):  
L Neigeborn ◽  
P Schwartzberg ◽  
R Reid ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Uptake ◽  
Gene Disruption ◽  
Glucose Repression ◽  
Gene Products ◽  
Missense Mutations ◽  
Chromosomal Locus ◽  
Growth Properties ◽  
Invertase Gene ◽  
Regulatory Functions

Missense mutations in the SNF3 gene of Saccharomyces cerevisiae were previously found to cause defects in both glucose repression and derepression of the SUC2 (invertase) gene. In addition, the growth properties of snf3 mutants suggested that they were defective in uptake of glucose and fructose. We have cloned the SNF3 gene by complementation and demonstrated linkage of the cloned DNA to the chromosomal SNF3 locus. The gene encodes a 3-kilobase poly(A)-containing RNA, which was fivefold more abundant in cells deprived of glucose. The SNF3 gene was disrupted at its chromosomal locus by several methods to create null mutations. Disruption resulted in growth phenotypes consistent with a defect in glucose uptake. Surprisingly, gene disruption did not cause aberrant regulation of SUC2 expression. We discuss possible mechanisms by which abnormal SNF3 gene products encoded by missense alleles could perturb regulatory functions.

scholarly journals Null mutations in the SNF3 gene of Saccharomyces cerevisiae cause a different phenotype than do previously isolated missense mutations.

1986 ◽  
Vol 6 (11) ◽  
pp. 3569-3574 ◽  
Author(s):  
L Neigeborn ◽  
P Schwartzberg ◽  
R Reid ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Uptake ◽  
Gene Disruption ◽  
Glucose Repression ◽  
Gene Products ◽  
Missense Mutations ◽  
Chromosomal Locus ◽  
Growth Properties ◽  
Invertase Gene ◽  
Regulatory Functions

Missense mutations in the SNF3 gene of Saccharomyces cerevisiae were previously found to cause defects in both glucose repression and derepression of the SUC2 (invertase) gene. In addition, the growth properties of snf3 mutants suggested that they were defective in uptake of glucose and fructose. We have cloned the SNF3 gene by complementation and demonstrated linkage of the cloned DNA to the chromosomal SNF3 locus. The gene encodes a 3-kilobase poly(A)-containing RNA, which was fivefold more abundant in cells deprived of glucose. The SNF3 gene was disrupted at its chromosomal locus by several methods to create null mutations. Disruption resulted in growth phenotypes consistent with a defect in glucose uptake. Surprisingly, gene disruption did not cause aberrant regulation of SUC2 expression. We discuss possible mechanisms by which abnormal SNF3 gene products encoded by missense alleles could perturb regulatory functions.

scholarly journals A novel signal transduction pathway in Saccharomyces cerevisiae defined by Snf3-regulated expression of HXT6.

1996 ◽  
Vol 7 (12) ◽  
pp. 1953-1966 ◽  
Author(s):  
H Liang ◽  
R F Gaber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Signal Transduction ◽  
Glucose Uptake ◽  
Glucose Repression ◽  
Carbon Sources ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Signaling Mechanism ◽  
High Concentrations ◽  
Delta Cells

We show that cells deleted for SNF3, HXT1, HXT2, HXT3, HXT4, HXT6, and HXT7 do not take up glucose and cannot grow on media containing glucose as a sole carbon source. The expression of Hxt1, Hxt2, Hxt3, Hxt6, or Gal2 in these cells resulted in glucose transport and allowed growth on glucose media. In contrast, the expression of Snf3 failed to confer glucose uptake or growth on glucose. HXT6 is highly expressed on raffinose, low glucose, or nonfermentable carbon sources but is repressed in the presence of high concentrations of glucose. The maintenance of HXT6 glucose repression is strictly dependent on Snf3 and not on intracellular glucose. In snf3 delta cells expression of HXT6 is constitutive even when the entire repertoire of HXT genes is present and glucose uptake is abundant. In addition, glucose repression of HXT6 does not require glucose uptake by HXT1, HXT2, HXT3 or HXT4. We show that a signal transduction pathway defined by the Snf3-dependent hexose regulation of HXT6 is distinct from but also overlaps with general glucose regulation pathways in Saccharomyces cerevisiae. Finally, glucose repression of ADH2 and SUC2 is intact in snf3 delta hxt1 delta hxt2 delta hxt3 delta hxt4 delta hxt6 delta hxt7 delta gal2 cells, suggesting that the sensing and signaling mechanism for general glucose repression is independent from glucose uptake.

Evidence for orientation-conserved transfer in the TCA cycle in Saccharomyces cerevisiae: carbon-13 NMR studies

Biochemistry ◽  
1993 ◽  
Vol 32 (47) ◽  
pp. 12725-12729 ◽  
Author(s):  
B. Sumegi ◽  
A. D. Sherry ◽  
C. R. Malloy ◽  
P. A. Srere
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Tca Cycle ◽  
Nmr Studies ◽  
The Tca Cycle

Effect of gene disruptions of the TCA cycle on production of succinic acid in Saccharomyces cerevisiae

1999 ◽  
Vol 87 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Yukihiko Arikawa ◽  
Tomoko Kuroyanagi ◽  
Makoto Shimosaka ◽  
Haruhiro Muratsubaki ◽  
Keiichiro Enomoto ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Succinic Acid ◽  
Tca Cycle ◽  
The Tca Cycle

scholarly journals In-Depth Profiling of Lysine-Producing Corynebacterium glutamicum by Combined Analysis of the Transcriptome, Metabolome, and Fluxome

2004 ◽  
Vol 186 (6) ◽  
pp. 1769-1784 ◽  
Author(s):  
Jens Olaf Krömer ◽  
Oliver Sorgenfrei ◽  
Kai Klopprogge ◽  
Elmar Heinzle ◽  
Christoph Wittmann
Keyword(s):  
Gene Expression ◽  
Glucose Uptake ◽  
Corynebacterium Glutamicum ◽  
Tca Cycle ◽  
Lysine Biosynthesis ◽  
Intracellular Metabolite ◽  
Lysine Production ◽  
The Tca Cycle ◽  
Depth Analysis

ABSTRACT An in-depth analysis of the intracellular metabolite concentrations, metabolic fluxes, and gene expression (metabolome, fluxome, and transcriptome, respectively) of lysine-producing Corynebacterium glutamicum ATCC 13287 was performed at different stages of batch culture and revealed distinct phases of growth and lysine production. For this purpose, 13C flux analysis with gas chromatography-mass spectrometry-labeling measurement of free intracellular amino acids, metabolite balancing, and isotopomer modeling were combined with expression profiling via DNA microarrays and with intracellular metabolite quantification. The phase shift from growth to lysine production was accompanied by a decrease in glucose uptake flux, the redirection of flux from the tricarboxylic acid (TCA) cycle towards anaplerotic carboxylation and lysine biosynthesis, transient dynamics of intracellular metabolite pools, such as an increase of lysine up to 40 mM prior to its excretion, and complex changes in the expression of genes for central metabolism. The integrated approach was valuable for the identification of correlations between gene expression and in vivo activity for numerous enzymes. The glucose uptake flux closely corresponded to the expression of glucose phosphotransferase genes. A correlation between flux and expression was also observed for glucose-6-phosphate dehydrogenase, transaldolase, and transketolase and for most TCA cycle genes. In contrast, cytoplasmic malate dehydrogenase expression increased despite a reduction of the TCA cycle flux, probably related to its contribution to NADH regeneration under conditions of reduced growth. Most genes for lysine biosynthesis showed a constant expression level, despite a marked change of the metabolic flux, indicating that they are strongly regulated at the metabolic level. Glyoxylate cycle genes were continuously expressed, but the pathway exhibited in vivo activity only in the later stage. The most pronounced changes in gene expression during cultivation were found for enzymes at entry points into glycolysis, the pentose phosphate pathway, the TCA cycle, and lysine biosynthesis, indicating that these might be of special importance for transcriptional control in C. glutamicum.

Liquid-liquid extraction of succinate using a dicopper cryptate

2020 ◽  
Author(s):  
Riccardo Mobili ◽  
Sonia La Cognata ◽  
Francesca Merlo ◽  
Andrea Speltini ◽  
Massimo Boiocchi ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Visible Spectrum ◽  
Tca Cycle ◽  
Residual Concentration ◽  
Waste Products ◽  
Liquid Liquid Extraction ◽  
The Tca Cycle ◽  
Quantitative Extraction ◽  
Uv Visible

<div> <p>The extraction of the succinate dianion from a neutral aqueous solution into dichloromethane is obtained using a lipophilic cage-like dicopper(II) complex as the extractant. The quantitative extraction exploits the high affinity of the succinate anion for the cavity of the azacryptate. The anion is effectively transferred from the aqueous phase, buffered at pH 7 with HEPES, into dichloromethane. A 1:1 extractant:anion adduct is obtained. Extraction can be easily monitored by following changes in the UV-visible spectrum of the dicopper complex in dichloromethane, and by measuring the residual concentration of succinate in the aqueous phase by HPLC−UV. Considering i) the relevance of polycarboxylates in biochemistry, as e.g. normal intermediates of the TCA cycle, ii) the relevance of dicarboxylates in the environmental field, as e.g. waste products of industrial processes, and iii) the recently discovered role of succinate and other dicarboxylates in pathophysiological processes including cancer, our results open new perspectives for research in all contexts where selective recognition, trapping and extraction of polycarboxylates is required. </p> </div>

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