scholarly journals Metabolic Changes by Wine Flor-Yeasts with Gluconic Acid as the Sole Carbon Source

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 150
Author(s):  
Minami Ogawa ◽  
Jaime Moreno-García ◽  
Lucy C. M. Joseph ◽  
Juan C. Mauricio ◽  
Juan Moreno ◽  
...  

Gluconic acid consumption under controlled conditions by a Saccharomyces cerevisiae flor yeast was studied in artificial media. Gluconic acid was the sole carbon source and the compounds derived from this metabolism were tracked by endo-metabolomic analysis using a Gas Chromatography-Mass Spectrometry (GC-MSD) coupled methodology. After 6 days, about 30% of gluconic acid (1.5 g/L) had been consumed and 34 endo-metabolites were identified. Metabolomic pathway analysis showed the TCA cycle, glyoxylate-dicarboxylate, glycine-serine-threonine, and glycerolipid metabolic pathway were significantly affected. These results contribute to the knowledge of intracellular metabolomic fluctuations in flor yeasts during gluconic acid uptake, opening possibilities for future experiments to improve their applications to control gluconic acid contents during the production of fermented beverages.

Microbiology ◽  
2003 ◽  
Vol 149 (9) ◽  
pp. 2317-2329 ◽  
Author(s):  
Kousei Tanaka ◽  
Kazuo Kobayashi ◽  
Naotake Ogasawara

The Gram-positive bacterium Bacillus subtilis has a complete set of enzymes for the tricarboxylic acid (TCA) cycle and can grow aerobically using most of the TCA cycle intermediates (malate, fumarate, succinate and citrate) as a sole carbon source. The B. subtilis genome sequence contains three paralogous two-component regulatory systems, CitST, DctSR and YufLM. CitST and DctSR activate the expression of a transporter of the Mg2+–citrate complex (CitM) and a fumarate and succinate transporter (DctP), respectively. These findings prompted an investigation of whether the YufL sensor and its cognate regulator, YufM, play a role in malate uptake. This paper reports that the YufM regulator shows in vitro binding to the promoter region of two malate transporter genes, maeN and yflS, and is responsible for inducing their expression in vivo. It was also found that inactivation of the yufM or maeN genes resulted in bacteria that could not grow in a minimal salts medium containing malate as a sole carbon source, indicating that the induction of the MaeN transporter by the YufM regulator is essential for the utilization of malate as a carbon source. Inactivation of the yufL gene resulted in the constitutive expression of MaeN. This expression was suppressed by reintroduction of the kinase domain of YufL, indicating that the YufL sensor is required for proper signal detection and signalling specificity. The authors propose that a phosphatase activity of YufL plays an important role in the YufLM two-component regulatory system. The studies reported here have revealed that members of a set of paralogous two-component regulatory systems in B. subtilis, CitST, DctSR and YufLM, are involved in a related function – uptake (and metabolism) of the TCA cycle intermediates – but with distinct substrate specificities.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Arief Izzairy Zamani ◽  
Susann Barig ◽  
Sarah Ibrahim ◽  
Hirzun Mohd. Yusof ◽  
Julia Ibrahim ◽  
...  

Abstract Background Sugars and triglycerides are common carbon sources for microorganisms. Nonetheless, a systematic comparative interpretation of metabolic changes upon vegetable oil or glucose as sole carbon source is still lacking. Selected fungi that can grow in acidic mineral salt media (MSM) with vegetable oil had been identified recently. Hence, this study aimed to investigate the overall metabolite changes of an omnipotent fungus and to reveal changes at central carbon metabolism corresponding to both carbon sources. Results Targeted and non-targeted metabolomics for both polar and semi-polar metabolites of Phialemonium curvatum AWO2 (DSM 23903) cultivated in MSM with palm oil (MSM-P) or glucose (MSM-G) as carbon sources were obtained. Targeted metabolomics on central carbon metabolism of tricarboxylic acid (TCA) cycle and glyoxylate cycle were analysed using LC–MS/MS-TripleQ and GC–MS, while untargeted metabolite profiling was performed using LC–MS/MS-QTOF followed by multivariate analysis. Targeted metabolomics analysis showed that glyoxylate pathway and TCA cycle were recruited at central carbon metabolism for triglyceride and glucose catabolism, respectively. Significant differences in organic acids concentration of about 4- to 8-fold were observed for citric acid, succinic acid, malic acid, and oxaloacetic acid. Correlation of organic acids concentration and key enzymes involved in the central carbon metabolism was further determined by enzymatic assays. On the other hand, the untargeted profiling revealed seven metabolites undergoing significant changes between MSM-P and MSM-G cultures. Conclusions Overall, this study has provided insights on the understanding on the effect of triglycerides and sugar as carbon source in fungi global metabolic pathway, which might become important for future optimization of carbon flux engineering in fungi to improve organic acids production when vegetable oil is applied as the sole carbon source.


2002 ◽  
Vol 184 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Michael J. Hynes ◽  
Oliver W. Draht ◽  
Meryl A. Davis

ABSTRACT Phosphoenolpyruvate carboxykinase (PEPCK) is a key enzyme required for gluconeogenesis when microorganisms grow on carbon sources metabolized via the tricarboxylic acid (TCA) cycle. Aspergillus nidulans acuF mutants isolated by their inability to use acetate as a carbon source specifically lack PEPCK. The acuF gene has been cloned and shown to encode a protein with high similarity to PEPCK from bacteria, plants, and fungi. The regulation of acuF expression has been studied by Northern blotting and by the construction of lacZ fusion reporters. Induction by acetate is abolished in mutants unable to metabolize acetate via the TCA cycle, and induction by amino acids metabolized via 2-oxoglutarate is lost in mutants unable to form 2-oxoglutarate. Induction by acetate and proline is not additive, consistent with a single mechanism of induction. Malate and succinate result in induction, and it is proposed that PEPCK is controlled by a novel mechanism of induction by a TCA cycle intermediate or derivative, thereby allowing gluconeogenesis to occur during growth on any carbon source metabolized via the TCA cycle. It has been shown that the facB gene, which mediates acetate induction of enzymes specifically required for acetate utilization, is not directly involved in PEPCK induction. This is in contrast to Saccharomyces cerevisiae, where Cat8p and Sip4p, homologs of FacB, regulate PEPCK as well as the expression of other genes necessary for growth on nonfermentable carbon sources in response to the carbon source present. This difference in the control of gluconeogenesis reflects the ability of A. nidulans and other filamentous fungi to use a wide variety of carbon sources in comparison with S. cerevisiae. The acuF gene was also found to be subject to activation by the CCAAT binding protein AnCF, a protein homologous to the S. cerevisiae Hap complex and the mammalian NFY complex.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 302-302
Author(s):  
Wan Chi Chang ◽  
Jisun So ◽  
Stefania Lamon-Fava

Abstract Objectives The omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to have shared and independent effects on inflammation and on lipid and glucose metabolism. However, the differential effects of EPA and DHA on serum metabolome remain elusive in humans. Methods Twenty-one subjects (9 men and 12 women, 50–75 y) with chronic inflammation (C reactive protein > 2 μg/mL) were enrolled in a randomized, controlled crossover trial consisting of a 4-week lead-in phase (high oleic sunflower oil, 3 g/d; baseline) followed by randomization to two sequential 10-week supplementation phases with pure EPA and DHA (3 g/d each) separated by a 10-week washout. Primary metabolites (n = 129) were measured in fasting serum samples by gas chromatography-mass spectrometry. Linear-mixed model was created to compare changes in metabolites by EPA and DHA relative to baseline. Pathway analysis (MetaboAnalyst 4.0, https://www.metaboanalyst.ca) was performed to identify the biological pathways associated with affected metabolites. Results DHA altered a greater number of metabolites than EPA (19 vs 11). Both EPA and DHA significantly lowered constitutive metabolites of the TCA cycle and the alanine, aspartate and glutamate metabolism pathway, with DHA showing a greater reduction than EPA. EPA significantly increased UDP-glucuronic acid and glucuronic acid, and DHA increased only glucuronic acid, thus affecting pathways where these metabolites play key roles (ascorbate and aldarate metabolism; pentose and glucuronate interconversions). Conclusions DHA affected more metabolites than EPA. The greater impact of DHA on the TCA cycle and the larger effect of EPA on the glucose-derived glucuronic acid-related pathways suggest their differential ability to modulate metabolic pathways. Funding Sources Grant number: 2015–67,017-23,142 from the National Institute of Food and Agriculture, U.S. Department Of Agriculture.


Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1113 ◽  
Author(s):  
Gkiouli ◽  
Biechl ◽  
Eisenreich ◽  
Otto

In cancers, tumor cells are exposed to fluctuating nutrient microenvironments with limiting supplies of glucose and glutamine. While the metabolic program has been related to the expression of oncogenes, only fractional information is available on how variable precarious nutrient concentrations modulate the cellular levels of metabolites and their metabolic pathways. We thus sought to obtain an overview of the metabolic routes taken by 13C-glucose-derived metabolites in breast cancer MCF-7 cells growing in combinations of limiting glucose and glutamine concentrations. Isotopologue profiles of key metabolites were obtained by gas chromatography/mass spectrometry (GC/MS). They revealed that in limiting and standard saturating medium conditions, the same metabolic routes were engaged, including glycolysis, gluconeogenesis, as well as the TCA cycle with glutamine and pyruvate anaplerosis. However, the cellular levels of 13C-metabolites, for example, serine, alanine, glutamate, malate, and aspartate, were highly sensitive to the available concentrations and the ratios of glucose and glutamine. Notably, intracellular lactate concentrations did not reflect the Warburg effect. Also, isotopologue profiles of 13C-serine as well as 13C-alanine show that the same glucose-derived metabolites are involved in gluconeogenesis and pyruvate replenishment. Thus, anaplerosis and the bidirectional flow of central metabolic pathways ensure metabolic plasticity for adjusting to precarious nutrient conditions.


2006 ◽  
Vol 189 (3) ◽  
pp. 940-949 ◽  
Author(s):  
Yinjie Tang ◽  
Francesco Pingitore ◽  
Aindrila Mukhopadhyay ◽  
Richard Phan ◽  
Terry C. Hazen ◽  
...  

ABSTRACT Flux distribution in central metabolic pathways of Desulfovibrio vulgaris Hildenborough was examined using 13C tracer experiments. Consistent with the current genome annotation and independent evidence from enzyme activity assays, the isotopomer results from both gas chromatography-mass spectrometry (GC-MS) and Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) indicate the lack of an oxidatively functional tricarboxylic acid (TCA) cycle and an incomplete pentose phosphate pathway. Results from this study suggest that fluxes through both pathways are limited to biosynthesis. The data also indicate that >80% of the lactate was converted to acetate and that the reactions involved are the primary route of energy production [NAD(P)H and ATP production]. Independently of the TCA cycle, direct cleavage of acetyl coenzyme A to CO and 5,10-methyl tetrahydrofuran also leads to production of NADH and ATP. Although the genome annotation implicates a ferredoxin-dependent oxoglutarate synthase, isotopic evidence does not support flux through this reaction in either the oxidative or the reductive mode; therefore, the TCA cycle is incomplete. FT-ICR MS was used to locate the labeled carbon distribution in aspartate and glutamate and confirmed the presence of an atypical enzyme for citrate formation suggested in previous reports [the citrate synthesized by this enzyme is the isotopic antipode of the citrate synthesized by the (S)-citrate synthase]. These findings enable a better understanding of the relation between genome annotation and actual metabolic pathways in D. vulgaris and also demonstrate that FT-ICR MS is a powerful tool for isotopomer analysis, overcoming the problems with both GC-MS and nuclear magnetic resonance spectroscopy.


The biosynthesis in vivo of a number of amino acids, sugars, and purines in Paracoccus denitrificans grown on either [2, 3- 13 C]succinate or [1, 4- 13 C]succinate was investigated by using gas chromatography–mass spectrometry. The distribution of label in the TCA-cycle-related amino acids indicated that carbon intermediates of energy metabolism were utilized as precursors for the biosynthesis of these amino acids in vivo . The biosynthesis of glycine, serine, phenylalanine and glycerol from labelled succinate in vivo were consistent with phosphoenol pyruvate as an intermediate. A mechanism for the formation of C 4 , C 5 and C 6 sugars without the use of fructose-1, 6-bisphosphate aldolase (which has not been detected in P. denitrificans ) is proposed. The 13 C-enrichments of ribose in the bacterium indicate that there are at least three routes of ribose biosynthesis operating during growth on labelled succinate. The probability distribution of labelled purine molecules was successfully predicted for adenine, guanine and adenosine, thus confirming their generally accepted route of biosynthesis in vivo .


2021 ◽  
Vol 3 (Supplement_1) ◽  
pp. i15-i15
Author(s):  
Consuelo Torrini ◽  
Trang Nguyen ◽  
Chang Shu ◽  
Angeliki Mela ◽  
Nelson Humala ◽  
...  

Abstract Glioblastoma (GBM) is the most common primary malignant brain tumor with an unfavorable prognosis. While GBMs utilize glucose, there are other carbon sources at their disposal. Lactate accumulates to a significant amount in the infiltrative margin of GBMs. In the current study, we demonstrated that lactate rescued patient-derived xenograft (PDX) GBM cells from nutrient deprivation mediated cell death and inhibition of growth. Transcriptome analysis, ATAC-seq and CHIP-seq. showed that lactic acid exposure entertained a signature of cell cycle progression and oxidative phosphorylation (OXPHOS) /tricarboxylic acid (TCA)-cycle. LC/MS analysis demonstrated that U-13C-Lactate elicited substantial labeling of TCA-cycle metabolites, acetyl-CoA and histone protein acetyl-residues in PDX derived GBM cells. Given that acetyl-CoA is pivotal for histone acetylation we observed a dose-dependent elevation of histone marks (e.g. H3K27ac), which was rescued by genetic and pharmacological inhibition of lactic acid-uptake, ATP-citrate lyase, p300 histone-acetyl-transferase and OXPHOS, resulting in reversal of lactate mediated protection from cell death. CHIP-seq. analysis demonstrated that lactic acid facilitated enhanced binding of H3K27ac to gene promoters and cis-regulatory elements. Consistently, ATAC-seq. analysis highlighted enhanced accessibility of the chromatin by lactic acid. In a combined tracer experiment (U-13C-glucose and 3-C13-lactate), we made the fundamental observation that lactic acid carbons were predominantly labeling the TCA cycle metabolites over glucose, implying a critical role of lactic acid in GBMs. Finally, pharmacological blockage of the TCA-cycle, using a clinically validated drug, extended overall survival in an orthotopic PDX model in mice without induction of toxicity, implying a critical role of lactic acid in GBMs and establishing lactic acid metabolism as a novel drug target for GBM.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
John S. Hothersall ◽  
Aamir Ahmed

Catabolite repression (CCR) regulates amino acid permeases in Saccharomyces cerevisiae via a TOR-kinase mediated mechanism. When glucose, the preferred fuel in S. cerevisiae, is substituted by galactose, amino acid uptake is increased. Here we have assessed the contribution and metabolic significance of this surfeit of amino acid in yeast undergoing catabolite derepression (CDR). L-[U-14C]leucine oxidation was increased 15 ± 1 fold in wild type (WT) strain grown in galactose compared to glucose. Under CDR, leucine oxidation was (i) proportional to uptake, as demonstrated by decreased uptake and oxidation of leucine in strains deleted of major leucine permeases and (ii) entirely dependent upon the TCA cycle, as cytochrome c1 (Cyt1) deleted strains could not grow in galactose. A regulator of amino acid carbon entry into the TCA cycle, branched chain ketoacid dehydrogenase, was also increased 29 ± 3 fold under CCR in WT strain. Protein expression of key TCA cycle enzymes, citrate synthase (Cs), and Cyt1 was increased during CDR. In summary, CDR upregulation of amino acid uptake is accompanied by increased utilization of amino acids for yeast growth. The mechanism for this is likely to be an increase in protein expression of key regulators of the TCA cycle.


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