scholarly journals The Absence of Pyruvate Kinase Affects Glucose-Dependent Carbon Catabolite Repression in Bacillus subtilis

Metabolites ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 216 ◽  
Author(s):  
Sousa ◽  
Westhoff ◽  
Methling ◽  
Lalk
Keyword(s):  
Bacillus Subtilis ◽  
Pyruvate Kinase ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Carbon Sources ◽  
Defined Medium ◽  
Central Carbon Metabolism ◽  
Alternative Pathways ◽  
Distribution Point ◽  
Nutritional Compounds

Pyruvate is a key intermediate of diverse metabolic pathways of central carbon metabolism. In addition to being the end product of glycolysis, pyruvate is an essential carbon distribution point to oxidative metabolism, amino acid and fatty acid syntheses, and overflow metabolite production. Hence, a tight regulation of pyruvate kinase (Pyk) activity is of great importance. This study aimed to analyze targeted metabolites from several pathways and possible changes in Bacillus subtilis lacking Pyk. Wild type and Δpyk cells were cultivated in chemically defined medium with glucose and pyruvate as carbon sources, and the extracted metabolites were analyzed by 1H-NMR, GC-MS, HPLC-MS, and LC-MS/MS. The results showed that the perturbation created in the pyruvate node drove an adaptation to new conditions by altering the nutritional compounds’ consumption. In Δpyk, pyruvate, which is subject to glucose-dependent carbon catabolite repression, did not comply with the hierarchy in carbon source utilization. Other metabolic alterations were observed such as the higher secretion of the overflow metabolites acetoin and 2,3-butanediol by Δpyk. Our results help to elucidate the regulatory transport of glucose and pyruvate in B. subtilis and possible metabolic reroute to alternative pathways in the absence of Pyk.

scholarly journals Carbon Catabolite Repression in Bacillus subtilis: Quantitative Analysis of Repression Exerted by Different Carbon Sources

2008 ◽  
Vol 190 (21) ◽  
pp. 7275-7284 ◽  
Author(s):  
Kalpana D. Singh ◽  
Matthias H. Schmalisch ◽  
Jörg Stülke ◽  
Boris Görke
Keyword(s):  
Bacillus Subtilis ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Carbon Sources ◽  
Transport Activity ◽  
Phosphotransferase System ◽  
Phosphorylation State ◽  
Mechanism Operative

ABSTRACT In many bacteria glucose is the preferred carbon source and represses the utilization of secondary substrates. In Bacillus subtilis, this carbon catabolite repression (CCR) is achieved by the global transcription regulator CcpA, whose activity is triggered by the availability of its phosphorylated cofactors, HPr(Ser46-P) and Crh(Ser46-P). Phosphorylation of these proteins is catalyzed by the metabolite-controlled kinase HPrK/P. Recent studies have focused on glucose as a repressing substrate. Here, we show that many carbohydrates cause CCR. The substrates form a hierarchy in their ability to exert repression via the CcpA-mediated CCR pathway. Of the two cofactors, HPr is sufficient for complete CCR. In contrast, Crh cannot substitute for HPr on substrates that cause a strong repression. Determination of the phosphorylation state of HPr in vivo revealed a correlation between the strength of repression and the degree of phosphorylation of HPr at Ser46. Sugars transported by the phosphotransferase system (PTS) cause the strongest repression. However, the phosphorylation state of HPr at its His15 residue and PTS transport activity have no impact on the global CCR mechanism, which is a major difference compared to the mechanism operative in Escherichia coli. Our data suggest that the hierarchy in CCR exerted by the different substrates is exclusively determined by the activity of HPrK/P.

Effect of carbon source on extracellular (1 → 3)- and (1 → 6)-β-glucanase production by Acremonium persicinum

1997 ◽  
Vol 43 (5) ◽  
pp. 432-439 ◽  
Author(s):  
Stuart M. Pitson ◽  
Robert J. Seviour ◽  
Barbara M. McDougall
Keyword(s):  
Carbon Source ◽  
Filamentous Fungus ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Carbon Sources ◽  
Culture Filtrates ◽  
Regulation Of Synthesis

The effect of carbon source on the levels of three (1 → 3)-β-glucanases and a (1 → 6)-β-glucanase in the culture filtrates of the filamentous fungus Acremonium persicinum was investigated. All four enzymes were produced during growth of the fungus on (1 → 3)-, (1 → 6)-, and (1 → 3)(1 → 6)-β-glucans as well as β-linked oligoglucosides. However, only one (1 → 3)-β-glucanase and the (1 → 6)-β-glucanase were detected during growth on a range of other carbon sources including glucose, carboxymethylcellulose, and the α-glucan pullulan. The presence of glucose in the medium markedly decreased the production of all four glucanases, although the concentration required to effect complete repression of enzyme levels varied for the different enzymes. Similar repressive effects were also observed with sucrose, fructose, and galactose. The most likely explanations for these observations are that the synthesis of the (1 → 6)-β-glucanase and one of the (1 → 3)-β-glucanases is controlled by carbon catabolite repression, while the remaining two (1 → 3)-β-glucanases are inducible enzymes subject to carbon catabolite repression.Key words: (1 → 3)-β-glucanase, (1 → 6)-β-glucanase, Acremonium persicinum, regulation of synthesis, fungal β-glucanases.

scholarly journals YvcK of Bacillus subtilis is required for a normal cell shape and for growth on Krebs cycle intermediates and substrates of the pentose phosphate pathway

Microbiology ◽  
2005 ◽  
Vol 151 (11) ◽  
pp. 3777-3791 ◽  
Author(s):  
Boris Görke ◽  
Elodie Foulquier ◽  
Anne Galinier
Keyword(s):  
Bacillus Subtilis ◽  
Pentose Phosphate Pathway ◽  
Carbon Metabolism ◽  
Carbon Sources ◽  
Krebs Cycle ◽  
Normal Growth ◽  
Central Carbon Metabolism ◽  
Pentose Phosphate ◽  
Homologous Protein ◽  
Krebs Cycle Intermediates

The HPr-like protein Crh has so far been detected only in the bacillus group of bacteria. In Bacillus subtilis, its gene is part of an operon composed of six ORFs, three of which exhibit strong similarity to genes of unknown function present in many bacteria. The promoter of the operon was determined and found to be constitutively active. A deletion analysis revealed that gene yvcK, encoded by this operon, is essential for growth on Krebs cycle intermediates and on carbon sources metabolized via the pentose phosphate pathway. In addition, cells lacking YvcK acquired media-dependent filamentous or L-shape-like aberrant morphologies. The presence of high magnesium concentrations restored normal growth and cell morphology. Furthermore, suppressor mutants cured from these growth defects appeared spontaneously with a high frequency. Such suppressing mutations were identified in a transposon mutagenesis screen and found to reside in seven different loci. Two of them mapped in genes of central carbon metabolism, including zwf, which encodes glucose-6-phosphate dehydrogenase and cggR, the product of which regulates the synthesis of glyceraldehyde-3-phosphate dehydrogenase. All these results suggest that YvcK has an important role in carbon metabolism, probably in gluconeogenesis required for the synthesis of cell wall precursor molecules. Interestingly, the Escherichia coli homologous protein, YbhK, can substitute for YvcK in B. subtilis, suggesting that the two proteins have been functionally conserved in these different bacteria.

Phosphorylation of HPr and Crh by HprK, Early Steps in the Catabolite Repression Signalling Pathway for the Bacillus subtilis Levanase Operon

1999 ◽  
Vol 181 (9) ◽  
pp. 2966-2969 ◽  
Author(s):  
Isabelle Martin-Verstraete ◽  
Josef Deutscher ◽  
Anne Galinier
Keyword(s):  
Bacillus Subtilis ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Signalling Pathway ◽  
Catabolic Genes

ABSTRACT Carbon catabolite repression (CCR) of Bacillus subtiliscatabolic genes is mediated by CcpA and in part by P-Ser–HPr. For certain operons, Crh, an HPr-like protein, is also implicated in CCR. In this study we demonstrated that in ptsH1 crh1and hprK mutants, expression of the lev operon was completely relieved from CCR and that both P-Ser–HPr and P-Ser–Crh stimulated the binding of CcpA to the cresequence of the lev operon.

Catabolite repression-resistant mutants of Bacillus subtilis

1979 ◽  
Vol 25 (11) ◽  
pp. 1283-1287 ◽  
Author(s):  
I. Takahashi
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Catabolite Repression ◽  
Minimal Medium ◽  
Carbon Sources ◽  
Close Relation ◽  
Selection Technique ◽  
Source Studies ◽  
Resistant Mutants ◽  
Simple Selection

Mutants of Bacillus subtilis that are able to sporulate under the condition of catabolite repression were isolated by a simple selection technique. The mutants used in the present study were able to grow normally on minimal medium with ammonium sulphate as the nitrogen source and glucose as the carbon source. Studies carried out with these mutants show that there is no close relation between catabolite repression of an inducible enzyme, acetoin dehydrogenase, and that of sporulation. Certain mutants are able to sporulate in the presence of all the carbon sources tested but some mutants are resistant only to the carbon source used in isolation. It is suggested that several metabolic steps may be affected in catabolite repression of sporulation.

scholarly journals Drastic Differences in Crh and HPr Synthesis Levels Reflect Their Different Impacts on Catabolite Repression in Bacillus subtilis

2004 ◽  
Vol 186 (10) ◽  
pp. 2992-2995 ◽  
Author(s):  
Boris Görke ◽  
Laetitia Fraysse ◽  
Anne Galinier
Keyword(s):  
Bacillus Subtilis ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Catabolic Genes

ABSTRACT In Bacillus subtilis, carbon catabolite repression (CCR) of catabolic genes is mediated by ATP-dependent phosphorylation of HPr and Crh. Here we show that the different efficiencies with which these two proteins contribute to CCR may be due to the drastic differences in their synthesis rates under conditions that cause CCR.

scholarly journals Carbon Catabolite Repression Gene AoCreA Regulates Morphological Development and Ochratoxin A Biosynthesis Responding to Carbon Sources in Aspergillus ochraceus

Toxins ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 697
Author(s):  
Gang Wang ◽  
Yulong Wang ◽  
Bolei Yang ◽  
Chenxi Zhang ◽  
Haiyong Zhang ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Carbon Sources ◽  
Aspergillus Ochraceus ◽  
Morphological Development ◽  
Drastic Reduction ◽  
Food And Feed ◽  
Yeast Extract Sucrose ◽  
Insight Into

Carbon is one of the most important nutrients for the development and secondary metabolism in fungi. CreA is the major transcriptional factor mediating carbon catabolite repression, which is employed in the utilization of carbon sources. Aspergillus ochraceus contaminates various food and feed containing different carbon sources by producing ochratoxin A (OTA). However, little is known about the function of AoCreA in regulating the morphology and OTA production of A. ochraceus. To give an insight into the mechanism of the carbon sources regulating development of A. ochraceus and OTA production, we have identified AoCreA in A. ochraceus. The homologous recombination strategy was used to generate the AoCreA deletion mutant (ΔAoCreA). We have investigated the morphology and OTA production of the wild type (WT) and ΔAoCreA of A. ochraceus with media containing different carbon sources (glucose, fructose, maltose, D-xylose, D-mannose, acetate, D-galactose, D-mannitol and lactose). ΔAoCreA showed a significant growth and conidiation defect on all media as compared with WT. Glucose and maltose were the most inducing media for OTA production by A. ochraceus, followed by sucrose and the nutrient-rich Yeast Extract Sucrose (YES) and Potato Dextrose Agar (PDA). The deletion of AoCreA led to a drastic reduction of OTA production on all kinds of media except PDA, which was supported by the expression profile of OTA biosynthetic genes. Furthermore, infection studies of ΔAoCreA on oats and pears showed the involvement of AoCreA in the pathogenicity of A. ochraceus. Thus, these results suggest that AoCreA regulates morphological development and OTA biosynthesis in response to carbon sources in A. ochraceus.

scholarly journals trans-Acting Factors and cis Elements Involved in Glucose Repression of Arabinan Degradation in Bacillus subtilis

2007 ◽  
Vol 189 (22) ◽  
pp. 8371-8376 ◽  
Author(s):  
José Manuel Inácio ◽  
Isabel de Sá-Nogueira
Keyword(s):  
Bacillus Subtilis ◽  
Growth Phase ◽  
Exponential Growth ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Glucose Repression ◽  
Cis Elements ◽  
Promoter Regions ◽  
Transitional Phase

ABSTRACTInBacillus subtilis, the synthesis of enzymes involved in the degradation of arabinose-containing polysaccharides is subject to carbon catabolite repression (CCR). Here we show that CcpA is the major regulator of repression of the arabinases genes in the presence of glucose. CcpA acts via binding to onecreeach in the promoter regions of theabnAandxsagenes and to twocres in thearaABDLMNPQ-abfAoperon. The contributions of the coeffectors HPr and Crh to CCR differ according to growth phase. HPr dependency occurs during both exponential growth and the transitional phase, while Crh dependency is detected mainly at the transitional phase. Our results suggest that Crh synthesis may increase at the end of exponential growth and consequently contribute to this effect, together with other factors.

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