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PubMed1996

Muscle glycogen repletion from endogenous carbon sources during recovery from high intensity exercise in the fasted rat.

During recovery from high intensity exercise, substantial and rapid muscle glycogen repletion from endogenous carbon sources is reported in a variety of vertebrate species, the rat being the only reported exception. The major aim of this study was to re-examine the process of glycogen repletion during recovery from high intensity exercise in the rat. In response to 3 min of vigorous swimming, muscle glycogen concentrations decrease markedly from initial levels of 20.2 +/- 1.5 and 21.2 +/- 0.9 mumol g-1 to 6.4 +/- 1.1 and 7.9 +/- 1.4 mumol g-1 in the tibialis anterior and plantaris muscles respectively. The equivalent of 58% of the glycogen carbons mobilized during exercise by the plantaris and 73% of that mobilized by the tibialis anterior muscle is repleted within 1 h following exercise. Using the hepatectomized rat as experimental model, a secondary aim of the study was to evaluate whether the liver is essential for the repletion of muscle glycogen. Although the absence of significant differences in the magnitude of post-exercise muscle glycogen repletion between sham-operated and hepatectomized rats suggests that the resynthesis of muscle glycogen can take place in the absence of hepatic gluconeogenesis, the present study identifies several limitations in the use of acute hepatectomy. Overall, the present study indicates that, in contrast to published views, the rat resembles other vertebrates in that it can support extensive muscle glycogen repletion from endogenous carbon sources during the recovery phase following high intensity exercise.

Animals↗

PubMedDate not supplied

[The effect of the carbon sources and calcium ions on the activity of thermostable alpha-amylase in Bacillus sp. 86].

Amylolytic activity of Bacillus sp. 86 thermophilic strain was studied as affected by carbon sources. Glucose and saccharose being added to the nutrition medium with baker's yeast as the basic source of carbon the activity of alpha-amylase decreased. Introduction of native or soluble starch to the medium promoted a sharp increase in the enzymic activity. Bacillus sp. 86 being periodically cultivated in the optimized medium containing 4% of soluble starch and 0.5% of CaCl2, an eight-fold increase of amylolytic activity of cultural liquid was achieved as compared to the enzyme activity in the primary medium.

Bacillus↗

PubMed2002

Effect of carbon source and aeration rate on broth rheology and fungal morphology during red pigment production by Paecilomyces sinclairii in a batch bioreactor.

The influence of carbon source and aeration rate on fermentation broth rheology, mycelial morphology and red pigment production of Paecilomyces sinclairii was investigated in a 5-l stirred-tank bioreactor. The characteristics of P. sinclairii grown on starch and on sucrose medium were comparatively studied: the specific growth rate in sucrose medium (0.04 h(-1)) was higher than that in starch medium, whereas the specific production rate of red pigments (0.04 gg(-1)d(-1)) was favorable in starch medium. P. sinclairii grown in sucrose medium were highly branched and showed longer hyphal lengths than that in starch medium. The consistency index (K) in sucrose medium was markedly higher than that in starch medium due to higher cell mass, while the higher values of flow behavior index (n) were indicated at the late stationary phase in starch medium. The aeration rate was varied within the ranges from 0.5 to 3.5 vvm while running the fermentation at mild agitation of 150 rpm using sucrose as the carbon source. The maximum biomass concentration of P. sinclairii was about 33 gl(-1) with an aeration rate of 1.5 vvm, whereas the maximum yield of red pigment production (4.73 gl(-1)) was achieved with 3.5 vvm. The highly branched cell morphology appeared at 1.5 vvm and the highly vacuolated cell morphology was observed in a high aeration rate (3.5 vvm). There was no significant variance in rheological parameters (K and n) between culture broths from different aeration conditions.

Bioreactors↗

PubMed1999

Effect of carbon source, growth and temperature on the expression of the sec genes of Streptomyces lividans 1326

The mRNA level in sec genes of Streptomyces lividans was studied as a function of growth temperature, glucose effect, and growth using two different carbon sources. Glucose and xylan, a complex hemicellulose, were used as carbon sources for the growth of S. lividans. For both substrates, the mRNA levels of secA, secD, secE, secF, and secY genes were almost constant during the early and log phases, but showed a marked decrease at the beginning of the stationary phase followed by a full recovery of mRNA level in the late stationary phase. This indicates that the sec genes are actively transcribed during the differentiation process. The mRNA level in xylan was generally from 1.5- to 2-fold that in glucose. At growth temperatures of 28 degrees C, 34 degrees C, or 40 degrees C, there was no significant difference in the sec gene mRNA levels.

Journal Article↗

PubMed1965

Synthesis of Protocatechuate Oxygenase by Pseudomonas fluorescens in the Presence of Exogenous Carbon Sources.

Kirkland, Jerry J. (Oklahoma State University, Stillwater), and Norman N. Durham. Synthesis of protocatechuate oxygenase by Pseudomonas fluorescens in the presence of exogenous carbon sources. J. Bacteriol. 90:15-22. 1965.-The addition of glucose, ribose, or fructose (0.45 or 45.0 mumoles/ml) simultaneously with protocatechuic acid shortens the lag period required for synthesis of protocatechuate oxygenase by a washed-cell suspension of Pseudomonas fluorescens. Glucose is readily oxidized and supports growth of P. fluorescens, whereas neither ribose nor fructose readily supports growth. High glucose concentrations (45.0 mumoles/ml) shorten the lag period but lower the total enzyme synthesis. The pH drops during glucose oxidation, and this is accompanied by a decrease in the rate of enzyme synthesis. High glucose concentrations, with adequate buffering, permitted "normal" enzyme synthesis. A decrease in the total enzyme synthesis was not observed in the presence of high concentrations of ribose or fructose. Succinate, pyruvate, acetate, or formate (0.45 mumole/ml) were readily oxidized, but did not shorten the lag period required for synthesis of the enzyme. The data suggest that glucose, ribose, or fructose may serve as a "specific" carbon source (such as ribose-5-phosphate or a similar precursor important in ribonucleic acid synthesis) functional in the synthesis of protocatechuate oxygenase.

Journal Article↗

PubMed1996

Replication properties of ARS1 plasmids in Saccharomyces cerevisiae: dependence on the carbon source.

The replication behaviour of a number of ARS1-based plasmids was investigated on propagation in Saccharomyces cerevisiae grown with either glucose or galactose as carbon source. Growth on galactose results in reduced plasmid stability, as well as in reduced replication efficiency, when the entire 1.5-kb TRP1-ARS1 fragment is present on a plasmid. The galactose sensitivity is mediated by a 0.13-kb fragment harbouring part of the GAL3 promoter. This fragment exerts its effect when situated either 5' or 3' to the ARS core consensus at distances up to 0.9 kb. The endogenous 2 microns plasmid remained unaffected by the choice of carbon source.

Aldose-Ketose Isomerases↗

PubMed1995

Kinetic models of batch and fed-batch culture of single-cell protein with double carbon sources.

Unstructured logistic models were applied to simulate the kinetic process of the SCP batch culture with two species of yeast, in which glucose, xylose, or a mixture of the two were used as carbon sources. A modified logistic growth model was used to describe the fed-batch process of using mixed carbon sources. The model parameters were determined by the simulated model with the experimental data. The simulated curves of the models were in agreement with the experimental data.

Candida↗

PubMed1985

Regulation by carbon source of enzyme expression and slime production in bacterium W3A1.

Slime production by bacterium W3A1 was greatly enhanced during growth on methanol and, to a lesser extent, during growth on trimethylamine. Of the major dehydrogenases synthesized, trimethylamine and methylamine dehydrogenases were induced to different levels by certain carbon sources, while methanol dehydrogenase was expressed during growth on all carbon sources.

Alcohol Oxidoreductases↗

PubMed1981

Disappearance of guanosine 5'-diphosphate 3'-diphosphate in Bacillus subtilis vegetative cells upon carbon source deprivation.

Bacillus subtilis was grown in a nutrient medium, mNSMP, and a synthetic medium, mS6(C), in which spore formation was initiated after vegetative growth and exhaustion of carbon source or glucose. The amounts of intracellular phosphorylated compounds were analyzed at intervals by 2 M formic acid extraction and polyethyleneimine (PEI)-cellulose thin-layer chromatography followed by autoradiography. A hyperphosphorylated nucleotide, guanosine 5'-diphosphate 3'-diphosphate (ppGpp), was accumulated in cells during vegetative growth in both mNSMP and mS6(C), and then the nucleotide was degraded upon initiation of sporulation in both cases. Furthermore, after the nucleotide had disappeared in cells cultivated in mS6(C) upon exhaustion of the carbon source, it could be reformed in the sporulating cells by addition of glucose to the medium. These results suggest that the ppGpp in vegetative cells may function in the regulation of B. subtilis sporulation.

Bacillus subtilis↗

PubMed2000

Effects of Pinus sylvestris root growth and mycorrhizosphere development on bacterial carbon source utilization and hydrocarbon oxidation in forest and petroleum-contaminated soils.

The hypothesis that Pinus sylvestris L. root and mycorrhizosphere development positively influences bacterial community-linked carbon source utilization, and drives a concomitant reduction in mineral oil levels in a petroleum hydrocarbon- (PHC-) contaminated soil was confirmed in a forest ecosystem-based phytoremediation simulation. Seedlings were grown for 9 months in large petri dish microcosms containing either forest humus or humus amended with cores of PHC-contaminated soil. Except for increased root biomass in the humus/PHC treatment, there were no other significant treatment-related differences in plant growth and needle C and N status. Total cell and culturable bacterial (CFU) densities significantly increased in both rhizospheres and mycorrhizospheres that actively developed in the humus and PHC-contaminated soil. Mycorrhizospheres (mycorrhizas and extramatrical mycelium) supported the highest numbers of bacteria. Multivariate analyses of bacterial community carbon source utilization profiles (Biolog GN microplate) from different rhizosphere, mycorrhizosphere, and bulk soil compartments, involving principal component and correspondence analysis, highlighted three main niche-related groupings. The respective clusters identified contained bacterial communities from (i) unplanted bulk soils, (ii) planted bulk PHC and rhizospheres in PHC-contaminated soils, and (iii) planted bulk humus and rhizosphere/mycorrhizosphere-influenced humus, and mycorrhizosphere-influenced PHC contaminated soil. Correspondence analysis allowed further identification of amino acid preferences and increased carboxylic/organic acid preferences in rhizosphere and mycorrhizosphere compartments. Decreased levels of mineral oil (non-polar hydrocarbons) were detected in the PHC-contaminated soil colonized by pine roots and mycorrhizal fungi. These data further support our view that mycorrhizosphere development and function plays a central role in controlling associated bacterial communities and their degradative activities in lignin-rich forest humus and PHC-contaminated soils.

Bacteria↗

PubMed1998

Changes in size of intracellular pools of coenzyme A and its thioesters in Escherichia coli K-12 cells to various carbon sources and stresses.

Intracellular pools of three CoA molecular species of coenzyme A, CoASH, acetyl-CoA, and malonyl-CoA, in Escherichia coli K-12 cells were studied by acyl-CoA cycling method in replacement culture. The sizes and compositions of CoA pools starved for a carbon source changed within minutes after the addition of one of various carbon sources. A large acetyl-CoA pool formed after the addition of D-glucose, D-fructose, D-mannose, glycerol, or sorbitol, but there was little change when L-glucose, sucrose, maltose, succinate, or acetate was added. The beta-anomer of D-glucose was assimilated 10 times faster than the alpha-anomer. Intracellular CoA pools also changed with stress: in the pH, incubation temperature, or with osmotic stress. The sizes and compositions of CoA pools were not affected by pH changing between 4 and 8, but the breakdown of acetyl-CoA and CoASH was greater at pH 9 than at pH 4 to 8. Production of acetyl-CoA was greatest at 40 degrees C, and at 50 degrees C, an acetyl-CoA pool did not form at all and the size of the CoASH pool declined. When the organism was stressed by the addition of NaCl at concentrations of more than 0.6 M, little acetyl-CoA was produced. The total CoA pool (the sum of the concentrations of CoASH, acetyl-CoA, and malonyl-CoA) remained within the limits of 0.83-1.40 nmol/mg of dry cell weight (0.30-0.52 mM). Whenever acetyl-CoA increased, CoASH decreased. Therefore, the acetyl-CoA/CoASH ratio is an important index of facultative anaerobes that reflects the state of carbon and energy metabolism in vivo.

Acetyl Coenzyme A↗

PubMed2006

Effects of carbon source and Vitreoscilla hemoglobin (VHb) on the production of beta-galactosidase in Enterobacter aerogenes.

At fixed concentration (0.5%), lactose and galactose acted as inducers while glucose and other tested carbon sugars showed repression effects on beta-galactosidase production in Enterobacter aerogenes strain. The expression of Vitreoscilla hemoglobin gene (vgb) in this bacterial strain managed to overcome the repression effects as well as improving the induction of beta-galactosidase formation by carbon sources. In parallel, the bacterial O(2) consumption was increased correspondingly to the vgb induction of beta-galactosidase synthesis. When Enterobacter aerogenes strains were grown at the incubation temperature 42 degrees C, about 5-fold higher enzyme productivity was obtained than with a similar incubation at 37 degrees C. The bacterial growth expressed as biomass yield had a different optimum temperature and was not influenced to the same extent by variations in the carbon sources. These data are discussed in terms of proposed enhancement in beta-galactosidase productivity by vgb expression as well as its significance to improve the technology of whey processing.

Bacterial Proteins↗

PubMed2003

Effect of carbon source on biological nutrient removal in a sequencing batch reactor.

Sequencing batch operation was used for nutrient (COD, NH4-N, NO3-N, PO4-P) removal from synthetic wastewater by using different carbon sources. Operation consisted of anaerobic, anoxic, oxic, anoxic and oxic (An/Ax/Ox/Ax/Ox) phases with durations of 2/1/4.5/1.5/1.5 h. Glucose, acetate and a mixture of glucose/acetate were used as carbon source to yield a COD/N/P ratio of 100/5/1.5 in the feed. Sludge age was kept constant at 10 days. COD, NH4-N, NO3-N and PO4-P removal efficiencies were maximum at the levels of 96%, 87%, 81% and 90% respectively, when a mixture (50/50) of glucose and acetate was used.

Acetic Acid↗

PubMed2006

Biosurfactant production by Rhodococcus erythropolis grown on glycerol as sole carbon source.

The production of biosurfactant by Rhodococcus erythropolis during the growth on glycerol was investigated. The process was carried out at 28 degrees C in a 1.5-L bioreactor using glycerol as carbon source. The bioprocess was monitored through measurements of biosurfactant concentration and glycerol consumption. After 51 h of cultivation, 1.7 g/L of biosurfactant, surface, and interfacial tensions values (with n-hexadecane) of 43 and 15 mN/m, respectively, 67% of Emulsifying Index (E24), and 94% of oil removal were obtained. The use of glycerol rather than what happens with hydrophobic carbon source allowed the release of the biosurfactant, originally associated to the cell wall.

Bioreactors↗

PubMed1986

Regulation of phosphoenolpyruvate carboxykinase and pyruvate kinase in Saccharomyces cerevisiae grown in the presence of glycolytic and gluconeogenic carbon sources and the role of mitochondrial function on gluconeogenesis.

Phosphoenolpyruvate carboxykinase (PEPCKase) and pyruvate kinase (PKase) were measured in Saccharomyces cerevisiae grown in the presence of glycolytic and gluconeogenic carbon sources. The PEPCKase activity was highest in ethanol-grown cells. However, high PEPCKase activity was also observed in cells grown in 1% glucose, especially as compared with the activity of sucrose-, maltose-, or galactose-grown cells. Activity was first detected after 12 h when glucose was exhausted from the growth medium. The PKase activity was very high in glucose-grown cells; considerable activity was also present in ethanol- and pyruvate-grown cells. The absolute requirement of respiration for gluconeogenesis was demonstrated by the absence or significantly low levels of PEPCKase and fructose-1,6-bisphosphatase activities observed in respiratory deficient mutants, as well as in wild-type S. cerevisiae cells grown in the presence of glucose and antimycin A or chloramphenicol. Obligate glycolytic and gluconeogenic enzymes were present simultaneously only in stationary phase cells, but not in exponential phase cells; hence futile cycling could not occur in log phase cells regardless of the presence of carbon source in the growth medium.

Gluconeogenesis↗

PubMed1989

Role of gene duplications in the adaptation of Salmonella typhimurium to growth on limiting carbon sources.

Duplication-containing cells are selected when growth of Salmonella typhimurium is limited by the availability of any one of several carbon and energy sources. Under conditions of extreme starvation, growth occurs almost exclusively in the duplication-containing fraction of the population. Cells with duplications of one large segment of the chromosome are repeatedly selected regardless of which of these carbon sources limits growth. The duplicated chromosomal segment encodes the transport systems for all of these carbon sources. This duplication is not selected during growth on a carbon source for which the permease is not included within the duplication segment. This suggests that the growth advantage conferred by the duplication may be due to increased transport of the limiting carbon source. Inclusion of the permease alone is not sufficient to explain the growth advantage of the duplications, since other common duplications that include the permease are not selected.

Adaptation, Physiological↗

PubMed1996

Sudden depletion of carbon source blocks translation, but not transcription, in the yeast Saccharomyces cerevisiae.

Expression of invertase in the yeast Saccharomyces cerevisiae is greatly delayed when derepression occurs in a medium that lacks a usable carbon source. The delay is not a consequence of defects in the transcription of the SUC2 gene but is due to the impossibility of translating the normal levels of mRNA generated under derepressing conditions. The inhibition of translation in the absence of glucose has to be considered when reporter genes such as E. coli lacZ are used to measure transcription in conditions of carbon source starvation.

Blotting, Northern↗

PubMed1963

SOME EFFECTS OF CARBON SOURCE, AERATION, AND TEMPERATURE ON GROWTH OF A PSYCHROPHILIC STRAIN OF PSEUDOMONAS FLUORESCENS.

Olsen, Ronald H. (University of Minnesota, St. Paul) and James J. Jezeski. Some effects of carbon source, aeration, and temperature on growth of a psychrophilic strain of Pseudomonas fluorescens. J. Bacteriol. 86:429-433. 1963.-A psychrophilic strain of Pseudomonas fluorescens was grown in stationary and aerated culture at 4, 10, 15, 20, 25, and 32 C. Generation times were determined for cultures growing in media containing glucose, monosodium citrate, or Casamino Acids as the primary carbon and energy source. The results indicated that growth on Casamino Acids with aeration contributed to significantly shorter generation times at low temperatures when compared with other media systems. Furthermore, temperature coefficients (Q(10) values) calculated from growth-velocity data showed that the effects of temperature on growth rate are influenced by the carbon source in the growth medium and by aeration.

Amino Acids↗