scholarly journals Glucose metabolism in the extreme thermoacidophilic archaebacterium Sulfolobus solfataricus

1984 ◽  
Vol 224 (2) ◽  
pp. 407-414 ◽  
Author(s):  
M De Rosa ◽  
A Gambacorta ◽  
B Nicolaus ◽  
P Giardina ◽  
E Poerio ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Sulfolobus Solfataricus ◽  
Oxidative Breakdown

Sulfolobus solfataricus is a thermophilic archaebacterium able to grow at 87 degrees C and pH 3.5 on glucose as sole carbon source. The organism metabolizes glucose by two main routes. The first route involves an ATP-dependent phosphorylation to give glucose 6-phosphate, which readily isomerizes to fructose 6-phosphate. In the second route, glucose is converted into gluconate by an NAD+-dependent dehydrogenation; gluconate is then dehydrated to 2-keto-3-deoxygluconate, which, in turn, is cleaved to pyruvate and glyceraldehyde. Each metabolic step has been tested in vitro at 70 degrees C on dialysed homogenates or partially purified fractions; minimal requirements of single enzymes have been evaluated. Identification of the intermediates is based on chromatographic, spectroscopic and/or synthetic evidence and on specific enzymic assays. The oxidative breakdown of glucose to pyruvate occurring in S. solfataricus differs from the Entner-Doudoroff pattern in that there is an absence of any phosphorylation step.

Isolation of alcohol oxidase and two other methanol regulatable genes from the yeast Pichia pastoris

1985 ◽  
Vol 5 (5) ◽  
pp. 1111-1121
Author(s):  
S B Ellis ◽  
P F Brust ◽  
P J Koutz ◽  
A F Waters ◽  
M M Harpold ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Alcohol Oxidase ◽  
Methylotrophic Yeasts ◽  
Sequence Analyses ◽  
Yeast Pichia Pastoris ◽  
Oxidation Of Methanol ◽  
Regulated Expression

The oxidation of methanol follows a well-defined pathway and is similar for several methylotrophic yeasts. The use of methanol as the sole carbon source for the growth of Pichia pastoris stimulates the expression of a family of genes. Three methanol-responsive genes have been isolated; cDNA copies have been made from mRNAs of these genes, and the protein products from in vitro translations have been examined. The identification of alcohol oxidase as one of the cloned, methanol-regulated genes has been made by enzymatic, immunological, and sequence analyses. Methanol-regulated expression of each of these three isolated genes can be demonstrated to occur at the level of transcription. Finally, DNA subfragments of two of the methanol-responsive genomic clones from P. pastoris have been isolated and tentatively identified as containing the control regions involved in methanol regulation.

scholarly journals Mycobacterium tuberculosis Is Able To Accumulate and Utilize Cholesterol

2009 ◽  
Vol 191 (21) ◽  
pp. 6584-6591 ◽  
Author(s):  
Anna Brzostek ◽  
Jakub Pawelczyk ◽  
Anna Rumijowska-Galewicz ◽  
Bozena Dziadek ◽  
Jaroslaw Dziadek
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Cytoplasmic Membrane ◽  
Degradation Pathway ◽  
Cholesterol Accumulation ◽  
Targeted Disruption ◽  
Future Studies

ABSTRACT It is expected that the obligatory human pathogen Mycobacterium tuberculosis must adapt metabolically to the various nutrients available during its cycle of infection, persistence, and reactivation. Cholesterol, which is an important part of the mammalian cytoplasmic membrane, is a potential energy source. Here, we show that M. tuberculosis grown in medium containing a carbon source other than cholesterol is able to accumulate cholesterol in the free-lipid zone of its cell wall. This cholesterol accumulation decreases the permeability of the cell wall for the primary antituberculosis drug, rifampin, and partially masks the mycobacterial surface antigens. Furthermore, M. tuberculosis was able to grow on mineral medium supplemented with cholesterol as the sole carbon source. Targeted disruption of the Rv3537 (kstD) gene inhibited growth due to inactivation of the cholesterol degradation pathway, as evidenced by accumulation of the intermediate, 9-hydroxy-4-androstene-3,17-dione. Our findings that M. tuberculosis is able to accumulate cholesterol in the presence of alternative nutrients and use it when cholesterol is the sole carbon source in vitro may facilitate future studies into the pathophysiology of this important deadly pathogen.

Enzymatic and 14C-mannitol studies of the Aspergillus mannitol metabolism

1970 ◽  
Vol 16 (5) ◽  
pp. 363-367 ◽  
Author(s):  
Wei Hwa Lee
Keyword(s):  
Glucose Metabolism ◽  
Carbon Source ◽  
Metabolic Rate ◽  
Sole Carbon Source ◽  
Glucose Oxidation ◽  
Sole Source ◽  
Aspergillus Species ◽  
Mannitol Metabolism

Aspergillus species (UC4177) accumulated mannitol from glucose substrate and it also used mannitol as the sole carbon source. Experiment with radioactive mannitol showed that the accumulation of mannitol and the oxidation of mannitol to CO2 proceeded simultaneously. The presence of glucose in the medium did not inhibit mannitol oxidation. Mannitol was oxidized at about 25% of the metabolic rate of glucose. The rate of mannitol oxidation and several of the enzymes directly involved in mannitol metabolism were unaffected by using glucose or mannitol as the sole source of carbon. Nine enzymes of glucose metabolism were tested and none appeared to limit the rate of glucose oxidation. Aspergillus phosphofructokinase was not inhibited by 2.4 mM ATP or 10 mM citrate. Possible enzymatic defects favoring mannitol accumulation were not found.

scholarly journals The Impact of Pyroglutamate:Sulfolobus acidocaldariusHas a Growth Advantage overSaccharolobus solfataricusin Glutamate-Containing Media

Archaea ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Anna M. Vetter ◽  
Julia Helmecke ◽  
Dietmar Schomburg ◽  
Meina Neumann-Schaal
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Sulfolobus Solfataricus ◽  
Cell Extract ◽  
Sulfolobus Acidocaldarius ◽  
Intracellular Accumulation ◽  
Efficient Utilization ◽  
Crude Cell Extract ◽  
Toxic Metabolites ◽  
The Impact

Microorganisms are well adapted to their habitat but are partially sensitive to toxic metabolites or abiotic compounds secreted by other organisms or chemically formed under the respective environmental conditions. Thermoacidophiles are challenged by pyroglutamate, a lactam that is spontaneously formed by cyclization of glutamate under aerobic thermoacidophilic conditions. It is known that growth of the thermoacidophilic crenarchaeonSaccharolobus solfataricus(formerlySulfolobus solfataricus) is completely inhibited by pyroglutamate. In the present study, we investigated the effect of pyroglutamate on the growth ofS. solfataricusand the closely related crenarchaeonSulfolobus acidocaldarius.In contrast toS. solfataricus,S. acidocaldariuswas successfully cultivated with pyroglutamate as a sole carbon source. Bioinformatical analyses showed that both members of theSulfolobaceaehave at least one candidate for a 5-oxoprolinase, which catalyses the ATP-dependent conversion of pyroglutamate to glutamate. InS. solfataricus, we observed the intracellular accumulation of pyroglutamate and crude cell extract assays showed a less effective degradation of pyroglutamate. Apparently,S. acidocaldariusseems to be less versatile regarding carbohydrates and prefers peptidolytic growth compared toS. solfataricus. Concludingly,S. acidocaldariusexhibits a more efficient utilization of pyroglutamate and is not inhibited by this compound, making it a better candidate for applications with glutamate-containing media at high temperatures.

scholarly journals In vitro fermentability of prebiotic oligosaccharides by lactobacilli

2012 ◽  
Vol 29 (Special Issue) ◽  
pp. S49-S54 ◽  
Author(s):  
G. Kunová ◽  
V. Rada ◽  
I. Lisová ◽  
Š. Ročková ◽  
E. Vlková
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Growth Curves ◽  
Exponential Phase ◽  
Carbohydrate Source ◽  
Viable Cells ◽  
Lysozyme Concentration ◽  
Pure Substances ◽  
Prebiotic Oligosaccharides

Twelve strains of lactobacilli were tested for their growth and ability to utilise six prebiotics (pure substances and commercially available prebiotics) as a sole carbon source. All strains showed a considerable growth on all prebiotics tested. Inulin was the best carbohydrate source for lactobacilli, followed by lactulose and raffinose. A massive increase of viable cells on commercial prebiotic mixtures (Vivinal, Oligomate 55, and Orafti P95) was also observed. Lysozyme susceptibility was assayed in 13 strains of lactobacilli. Eight out of 13 strains were completely resistant to the lysozyme concentration of 400 µg/ml, in the rest of the strains a slight delay of the exponential phase of the growth curves was observed. Lactobacilli tolerated lysozyme well and were able to utilise all prebiotics.

Saccharomyces cerevisiae glucose signalling regulator Mth1p regulates the organellar Na+/H+ exchanger Nhx1p

2010 ◽  
Vol 432 (2) ◽  
pp. 343-352 ◽  
Author(s):  
Keiji Mitsui ◽  
Masafumi Matsushita ◽  
Hiroshi Kanazawa
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Glucose Sensor ◽  
Ph Regulation ◽  
Gene Knockout ◽  
Carbon Sources ◽  
Acidic Ph ◽  
In Cells

Organelle-localized NHEs (Na+/H+ exchangers) are found in cells from yeast to humans and contribute to organellar pH regulation by exporting H+ from the lumen to the cytosol coupled to an H+ gradient established by vacuolar H+-ATPase. The mechanisms underlying the regulation of organellar NHEs are largely unknown. In the present study, a yeast two-hybrid assay identified Mth1p as a new binding protein for Nhx1p, an organellar NHE in Saccharomyces cerevisiae. It was shown by an in vitro pull-down assay that Mth1p bound to the hydrophilic C-terminal half of Nhx1p, especially to the central portion of this region. Mth1p is known to bind to the cytoplasmic domain of the glucose sensor Snf3p/Rgt2p and also functions as a negative transcriptional regulator. Mth1p was expressed in cells grown in a medium containing galactose, but was lost (possibly degraded) when cells were grown in medium containing glucose as the sole carbon source. Deletion of the MTH1 gene increased cell growth compared with the wild-type when cells were grown in a medium containing galactose and with hygromycin or at an acidic pH. This resistance to hygromycin or acidic conditions was not observed for cells grown with glucose as the sole carbon source. Gene knockout of NHX1 increased the sensitivity to hygromycin and acidic pH. The increased resistance to hygromycin was reproduced by truncation of the Mth1p-binding region in Nhx1p. These results implicate Mth1p as a novel regulator of Nhx1p that responds to specific extracellular carbon sources.

scholarly journals Impact of purified human milk oligosaccharides as a sole carbon source on the growth of lactobacilli in in vitro model

2015 ◽  
Vol 9 (9) ◽  
pp. 565-571 ◽  
Author(s):  
KRAUSOVA Gabriela ◽  
RADA Vojtech ◽  
MARSIK Petr ◽  
MUSILOVA Sarka ◽  
SVEJSTIL Roman ◽  
...  
Keyword(s):  
Carbon Source ◽  
Human Milk ◽  
Sole Carbon Source ◽  
In Vitro Model ◽  
Human Milk Oligosaccharides ◽  
Milk Oligosaccharides ◽  
Vitro Model

The Bacillus subtilis YufLM two-component system regulates the expression of the malate transporters MaeN (YufR) and YflS, and is essential for utilization of malate in minimal medium

Microbiology ◽  
2003 ◽  
Vol 149 (9) ◽  
pp. 2317-2329 ◽  
Author(s):  
Kousei Tanaka ◽  
Kazuo Kobayashi ◽  
Naotake Ogasawara
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Constitutive Expression ◽  
Tca Cycle ◽  
Regulatory Systems ◽  
The Tca Cycle ◽  
Two Component ◽  
Tca Cycle Intermediates

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.

scholarly journals In Vitro Fermentation of Breast Milk Oligosaccharides by Bifidobacterium infantis and Lactobacillus gasseri

2006 ◽  
Vol 72 (6) ◽  
pp. 4497-4499 ◽  
Author(s):  
Robert E. Ward ◽  
Milady Ni�onuevo ◽  
David A. Mills ◽  
Carlito B. Lebrilla ◽  
J. Bruce German
Keyword(s):  
Breast Milk ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Human Milk Oligosaccharides ◽  
Bifidobacterium Infantis ◽  
Milk Oligosaccharides ◽  
In Vitro Fermentation ◽  
Bacterial Populations ◽  
Lactobacillus Gasseri

ABSTRACT It has been proposed that human milk oligosaccharides (HMO) function as a prebiotic for bifidobacteria, yet this activity has not been adequately investigated. In this study, Bifidobacterium infantis was shown to ferment purified HMO as a sole carbon source, while another gut commensal, Lactobacillus gasseri, did not ferment HMO. Our results support the hypothesis that HMO selectively amplify bacterial populations in the infant intestine.

scholarly journals Isolation of alcohol oxidase and two other methanol regulatable genes from the yeast Pichia pastoris.

1985 ◽  
Vol 5 (5) ◽  
pp. 1111-1121 ◽  
Author(s):  
S B Ellis ◽  
P F Brust ◽  
P J Koutz ◽  
A F Waters ◽  
M M Harpold ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Alcohol Oxidase ◽  
Methylotrophic Yeasts ◽  
Sequence Analyses ◽  
Yeast Pichia Pastoris ◽  
Oxidation Of Methanol ◽  
Regulated Expression

The oxidation of methanol follows a well-defined pathway and is similar for several methylotrophic yeasts. The use of methanol as the sole carbon source for the growth of Pichia pastoris stimulates the expression of a family of genes. Three methanol-responsive genes have been isolated; cDNA copies have been made from mRNAs of these genes, and the protein products from in vitro translations have been examined. The identification of alcohol oxidase as one of the cloned, methanol-regulated genes has been made by enzymatic, immunological, and sequence analyses. Methanol-regulated expression of each of these three isolated genes can be demonstrated to occur at the level of transcription. Finally, DNA subfragments of two of the methanol-responsive genomic clones from P. pastoris have been isolated and tentatively identified as containing the control regions involved in methanol regulation.

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