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At least 1,423 records · Page 79Linked to original sources
PubMed2006

Brooklawnia cerclae gen. nov., sp. nov., a propionate-forming bacterium isolated from chlorosolvent-contaminated groundwater.

Two novel facultatively anaerobic bacterial strains, BL-34(T) and BL-35, isolated from groundwater contaminated by a mixture of chlorosolvents were characterized using a polyphasic approach. The two strains exhibited essentially identical taxonomic features except for a vitamin B(12) requirement by strain BL-35 for optimal growth. Phylogenetically, the isolates were affiliated with members of the family Propionibacteriaceae and were placed in a phylogenetic branch adjacent to, but distinct from, those of the genera Propionimicrobium, Propionibacterium, Luteococcus, Propioniferax and Tessaracoccus. The cells of the novel strains were Gram-positive, non-motile, non-spore-forming pleomorphic rods. They produced catalase but not oxidase, and nitrate reduction did not occur in peptone/yeast extract/glucose medium. Propionate and acetate were the predominant products of glucose fermentation. Fermentation occurred in the presence of 1,2-dichloroethane and 1,1,2-trichloroethane at concentrations up to at least 9.8 mM. The genomic DNA G+C content was 67.5-67.9 mol%. Menaquinone MK-9(H(4)) was the predominant respiratory quinone and meso-diaminopimelic acid was present in the cell-wall peptidoglycan layer. The major cellular fatty acids were C(15 : 0) and anteiso-C(15 : 0). On the basis of the results obtained in this study, strains BL-34(T) and BL-35 should be classified within a novel taxon, for which the name Brooklawnia cerclae gen. nov., sp. nov. is proposed. The type strain of Brooklawnia cerclae is BL-34(T) (=LMG 23248(T)=NRRL B-41418(T)). An additional strain, BL-35 (=LMG 23249=NRRL B-41419), was also characterized.

Actinobacteria↗
PubMed1982

Subcellular localization of the methylcitric-acid-cycle enzymes in propionate metabolism of Yarrowia lipolytica.

The subcellular localization of the four characteristic enzymes of the methylcitric acid cycle was studied with glucose-grown as well as n-alkane-grown cells of Yarrowia lipolytica. Microsomes and peroxisomes showed no cycle enzyme activities. The four cycle enzymes were constitutively localized in mitochondria, with the exception of the dual localization of the fourth enzyme, 2-methylisocitrate lyase, in mitochondria and cytoplasm, where the lyase may function to supply pyruvate (the end-product of the catabolism of the propionate residue) to various reactions.

Ascomycota↗
PubMed1997

Transport of propionate across the distal colonic epithelium of guinea pig in the presence and absence of bicarbonate and of chloride.

Short-chain fatty acids (SCFA) are rapidly absorbed in the large intestine. However, the mechanisms involved have not been fully delineated. Findings indicate that absorption of SCFA occurs in the undissociated form as well as by an anion exchange, whereby marked species and segmental differences are present. The guinea pig distal colon has certain peculiarities. Unidirectional fluxes of propionate across guinea pig distal colon were studied under short-circuit current conditions in Ussing chambers. Removal of bicarbonate caused reduction of mucosal-to-serosal fluxes by 30%, serosal-to-mucosal fluxes were little affected. In chloride-free solution unidirectional fluxes were also reduced. However, in the presence of transepithelial chloride-gradients with the Cl(-)-free solution only at the luminal side, no such effects were seen. Findings support the presence of SCFA(-)-HCO3- exchange in guinea pig distal colon. Chloride seems not of major importance for SCFA transport.

Animals↗
PubMed1996

Influence of extracellular pH, sodium propionate and trimethylamine on excitation-contraction coupling in the rat tail artery.

1. The effects of extracellular or intracellular pH changes on agonist- or depolarization-induced contractions of the rat tail artery were investigated. 2. Vessels were perfused initially (25 min) with physiological salt solution (PSS) at a pressure of 30 mmHg. Perfusion was then continued with calcium-free PSS containing either 3.0 micromol/L noradrenaline (NA) or 100 mmol/L K+, which had been made either acidotic or alkalotic. Contractile responses to graded concentrations of calcium were assessed. 3. A reduction in the intracellular or extracellular pH was induced by the addition of a weak acid (30 mmol/L sodium propionate) or reduction of the concentration of HCO3- in the PSS, respectively; an elevation of the intracellular or extracellular pH was produced by the addition of a weak base (10 mmol/L trimethylamine) or by increasing HCO3-, respectively. The PSS was bubbled with 5% CO2/95% O2. 4. Lowered intracellular pH did not alter NA- or K+-stimulated contractions. During lowered extracellular pH, contractile responsiveness and peak response were significantly reduced in K+-stimulated arteries, but were not affected in NA-stimulated arteries. 5. Elevated intracellular pH did not alter NA-induced contraction, but reduced the sensitivity to K+-stimulated contractions. Elevated extracellular pH had little effect on the magnitude of K+-induced contractions, but slightly enhanced (although not significantly) NA-induced contractions. 6. It is concluded that reduced contractile responses to K+ during extracellular acidosis are due to the modulation of potential-operated calcium channels (POC). Alkalotic vasodilatation is mediated by intracellular events and is POC-modulated, whereas alkalotic vasoconstriction appears to be due to extracellular events and is modulated by receptor-operated calcium channels (ROC).

Animals↗
PubMed1983

The neuropathology of propionic acidemia.

The neuropathology in two biochemically documented cases of propionic acidemia is presented. While spongiform changes in white matter were seen in the infant who died at 12 days, no such changes were evident in an older patient who died at age 23 months. These findings are compared with other aminoacidemias.

Amino Acid Metabolism, Inborn Errors↗
PubMed2006

Identification of a new functional target of haloperidol metabolite: implications for a receptor-independent role of 3-(4-fluorobenzoyl) propionic acid.

Haloperidol, a dopamine D2 receptor blocker, is a classical neuroleptic drug that elicits extrapyramidal symptoms. Its metabolites include 3-(4-fluorobenzoyl) propionic acid (FBPA) and 4-(4-chlorophenyl)-4-piperidinol (CPHP). Until now, the biological significance of these metabolites has remained largely unknown. Here, we report that the administration of FBPA to mice effected a suppression of locomotor activity and induced catalepsy in a manner similar to that observed with haloperidol, whereas CPHP had no significant effects. Neither of these two metabolites, however, exhibited any ability to bind to the dopamine D2 receptor. FBPA blocked dopamine-induced extracellular signal-regulated kinase 1/2 phosphorylation, and it specifically affected mitogen-activated protein kinase kinase (MEK)1/2 activity in hippocampal HN33 cells. Moreover, FBPA was capable of direct interaction with MEK1/2, and inhibited its activity in vitro. We demonstrated the generation of haloperidol metabolites within haloperidol-treated cells by mass spectrometric analyses. Collectively, our results confirm the biological activity of FBPA, and provide initial clues as to the receptor-independent role of haloperidol.

Animals↗
PubMed1981

Effects of a salt of cholestyramine and 2-[4-(p-chlorobenzoyl)phenoxy]2-methyl propionic acid (alpha-1081) on biliary lipid secretion in rats.

1 Hypolipidaemic agents may increase biliary cholesterol in man, inducing a supersaturated bile. 2 To evaluate this possible side-effect, we have studied bile lipid secretion over a period of 8 h with intact enterohepatic circulation and 4 h with complete interruption in rats treated for two months with a salt of cholestyramine and 2-[4-(p-chlorobenzoyl)-phenoxy]2-methyl propionic acid (alpha-1081, 1.150 g/kg body wt., daily), cholestyramine (1.125 g/kg body wt. daily), procetofenic acid (25 mg/kg body wt. daily) and saline respectively (six rats for each group). 3 Cholesterol saturation index significantly (P less than 0.005) increased (from 0.21 +/- 0.01 to 0.39 +/- 0.09, mean +/- s.d.), in rats fed with procetofenic acid but it did not in alpha-1081- and cholestyramine-treated animals. 4 Procetofenic acid and, to a lesser extent, cholestyramine increased the bile flow. Procetofenic acid increased cholesterol secretion from 0.45 +/- 0.17 to 0.94 +/- 0.19 mumol kg-1 body wt. h-1 (mean +/- s.d.). 5 Cholestyramine increased both serum cholesterol and bile acid secretion from 0.45 +/- 0.17 to 0.68 +/- 0.10 and 25.8 +/- 9.48 to 39.96 +/- 6.68 mumol kg-1 body wt. h-1 respectively; alpha-1081, on the contrary, had no effect on bile lipid secretion. 6 These data suggest that alpha-1081 may be used as a new hypolipidaemic drug without any risk of increasing cholesterol in bile.

Animals↗
PubMed2006

Acetate, lactate, propionate, and isobutyrate as electron donors for iron and sulfate reduction in Arctic marine sediments, Svalbard.

The contribution of volatile fatty acids (VFA) as e(-)-donors for anaerobic terminal oxidation of organic carbon through iron and sulfate reduction was studied in Arctic fjord sediment. Dissolved inorganic carbon, Fe(2+), VFA concentrations, and sulfate reduction were monitored in slurries from the oxidized (0-2 cm) and the reduced (5-9 cm) zone. In the 0-2 cm layer, 2/3 of the mineralization could be attributed to sulfate reduction and 1/3 to iron reduction. In the 5-9 cm layer, sulfate reduction was the sole mineralization process. Acetate and lactate turnover rates were measured by radiotracer. Inhibition of sulfate reduction with selenate resulted in the accumulation of acetate, propionate, and isobutyrate. The acetate turnover rates determined by radiotracer and accumulation after inhibition were similar. VFA turnover accounted for 21% and 52% of the mineralization through sulfate reduction in the 0-2 and 5-9 cm layer, respectively. Acetate and lactate turnover in the inhibited 0-2 cm slurry was attributed to iron reduction and accounted for 10% and 2% of the iron reduction. Therefore, 88% and 79% of the iron and sulfate reduction in the 0-2 cm layer, respectively, must be fueled by alternative e(-)-donors. The accumulation of VFA in the selenate-inhibited 0-2 cm slurry did not enhance iron reduction, indicating that iron reducers were not limited by VFA availability.

Acetates↗
PubMed1996

Purification and characterization of malate dehydrogenase from the syntrophic propionate-oxidizing bacterium strain MPOB.

Malate dehydrogenase from the syntrophic propionate-oxidizing bacterium strain MPOB was purified 42-fold. The native enzyme had an apparent molecular mass of 68 kDa and consisted of two subunits of 35 kDa. The enzyme exhibited maximum activity with oxaloacetate at pH 8.5 and 60 degrees C. The Ka for oxaloacetate was 50 microM and for NADH 30 microM. The Km values for L-malate and NAD were 4 and 1.1 mM, respectively. Substrate inhibition was found at oxaloacetate concentrations higher than 250 microM. The N-terminal amino acid sequence of the enzyme was similar to the sequences of a variety of other malate dehydrogenases from plants, animals and micro-organisms.

Amino Acid Sequence↗
PubMed1996

Parathyroid hormone resistance and B cell lymphopenia in propionic acidemia.

The mechanisms of hypocalcemia, recurrent infections and hypogammaglobulinemia associated with metabolic decompensation of propionic acidemia due to propionyl-CoA carboxylase deficiency have not been defined. A 7-week-old infant with this disorder presented with severe hypocalcemia and B cell lymphopenia during an episode of metabolic acidosis and hyperammonemia. Hypocalcemia (1.1 mmol l-1) was associated with elevated serum intact parathyroid hormone (122 ng l-1), hyperphosphatemia, hypophosphaturia and hypercalcuria, indicating parathyroid hormone resistance. B cell lymphopenia (20 cells microliters-1) was associated with transient neutropenia, anemia and subsequent hypogamma-globulinemia (IgG < 294 mg dl-1, IgM < 8 mg dl-1, IgA < 8 mg dl-1), while T cells were normal. Parathyroid hormone resistance and B cell lymphopenia resolved following treatment with hemodialysis, diet and carnitine. These complications may be due to interference with parathyroid hormone renal tubular action and B cell maturation/proliferation by accumulated organic acids.

Amino Acid Metabolism, Inborn Errors↗
PubMed1972

L- -methyl- -hydrazino- -(3,4-dihydroxyphenyl)propionic acid: relative lack of antidecarboxylase activity in adrenals.

In rats previously treated with a monoamine oxidase inhibitor, the administration of 5-hydroxytryptophan results in increases in concentrations of 5-hydroxytryptamine in kidney, brain, and adrenal glands. When the peripheral L-aromatic amino acid decarboxylase inhibitor, L-alpha-methyl-alpha-hydrazino-beta-(3,4-dihydroxyphenyl)propionic acid (HMD) is administered prior to 5-hydroxytryptophan, the concentration of 5-hydroxytryptamine in kidneys does not rise, that of the brain increases slightly, and that of the adrenal rises markedly. This indicates that although the adrenal gland is a peripheral organ, it does not respond in the typical manner to the antidecarboxylase action of HMD. These results suggest that HMD does not gain free access into the adrenal medulla and that a possible "blood-adrenal barrier" may exist to this compound.

5-Hydroxytryptophan↗
PubMed1996

Detection and localization of syntrophic propionate-oxidizing bacteria in granular sludge by in situ hybridization using 16S rRNA-based oligonucleotide probes.

In situ hybridization with fluorescent oligonucleotides was used to detect and localize microorganisms in the granules of two lab-scale upflow anaerobic sludge blanket reactors that had been fed for several months with either sucrose or a mixture of volatile fatty acids. Sections of the granules were hybridized with 16S rRNA-targeted oligonucleotide probes for Bacteria, Archaea, specific phylogenetic groups of methanogens, and two syntrophic propionate-oxidizing strains, MPOB and KOPROP1. Cells of the syntrophic strain KOPROP1 were not detected in either type of sludge granules. Hybridizations of the sucrose-fed granules showed an outer layer of mainly bacterial microcolonies with different morphologies. More inwards of these granules, a layer of different methanogenic microcolonies mixed with large colonies of the syntrophic strain MPOB could be detected. The MPOB colonies were intertwined with hydrogen- or formate-consuming methanogens, indicating their syntrophic growth. The granules fed with volatile fatty acids showed an outer layer of mainly bacteria and then a thick layer of Methanosaeta-like methanogens mixed with a few bacteria and a layer of methanogens mixed with syntrophic MPOB microcolonies. The centers of both sludge types consisted of large cavities and methanogenic microcolonies. These results indicate a juxtapositioning of syntrophic bacteria and methanogens and provide additional evidence for a layered microbial architecture of anaerobic granular sludge.

Bacteria↗
PubMed1969

Effect of chloral hydrate on methane and propionic acid in the rumen.

Methane production from pyruvate by mixed rumen bacteria in vitro was nearly totally inhibited by chloral hydrate (0.1 mumole/ml of incubation fluid). This effect was accompanied by an accumulation of gaseous hydrogen and an increase in propionic acid production. Infusion of chloral hydrate (4 g/day) into the rumen of a sheep produced the same effects. Evidence is presented for a direct toxic effect of chloral hydrate upon methane bacteria. Results are discussed in terms of fermentation balances.

Animals↗
PubMed1995

DNA polymerase I function is required for the utilization of ethanolamine, 1,2-propanediol, and propionate by Salmonella typhimurium LT2.

Evidence documenting the requirement for a functional DNA polymerase I when Salmonella typhimurium LT2 uses ethanolamine (EA), 1,2-propanediol (1,2-PDL), or propionate (PRP) as the sole carbon and energy source is presented. Providing rat polymerase beta in trans demonstrated that the growth phenotypes observed were due exclusively to the lack of DNA polymerase I functions. The location of the mutation (a MudI1734 insertion) that rendered cells unable to grow on EA, 1,2-PDL, or PRP was determined by DNA sequencing to be within the polA gene. polA mutants of this bacterium may be unable to repair the damage caused by reactive aldehydes generated during the catabolism of EA, 1,2-PDL, or PRP. Consistent with this hypothesis, the inhibitory effects of acetaldehyde and propionaldehyde on the growth of this polA mutant were demonstrated. A derivative of the polA mutant unable to synthesize glutathione (GSH) was markedly more sensitive to acetaldehyde and propionaldehyde than was the polA mutant proficient in GSH synthesis. This finding was in agreement with the recently proposed role of GSH as a mechanism for quenching reactive aldehydes generated during the catabolism of these compounds (M. R. Rondon, R. Kazmierczack, and J. C. Escalante-Semerena, J. Bacteriol. 177:5434-5439, 1995).

Animals↗
PubMed2005

Catabolite repression of the propionate catabolic genes in Escherichia coli and Salmonella enterica: evidence for involvement of the cyclic AMP receptor protein.

Previous studies with Salmonella enterica serovar Typhimurium LT2 demonstrated that transcriptional activation of the prpBCDE operon requires the function of transcription factor PrpR, sigma-54, and IHF. In this study, we found that transcription from the prpBCDE and prpR promoters was down-regulated by the addition of glucose or glycerol, indicating that these genes may be regulated by the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex. Targeted mutagenesis of a putative CRP-binding site in the promoter region between prpR and prpBCDE suggested that these genes are under the control of CRP. Furthermore, cells with defects in cya or crp exhibited reduced transcriptional activation of prpR and prpBCDE in Escherichia coli. These results demonstrate that propionate metabolism is subject to catabolite repression by the global transcriptional regulator CRP and that this regulation is effected through control of both the regulator gene prpR and the prpBCDE operon itself. The unique properties of the regulation of these two divergent promoters may have important implications for mechanisms of CRP-dependent catabolite repression acting in conjunction with a member of the sigma-54 family of transcriptional activators.

Escherichia coli↗
PubMed2006

Mechanism of hilA repression by 1,2-propanediol consists of two distinct pathways, one dependent on and the other independent of catabolic production of propionate, in Salmonella enterica serovar Typhimurium.

A glycerol dehydrogenase gene was selected as a multicopy suppressor rescuing the reduced hilA expression in the Salmonella enterica serovar Typhimurium cpxA mutant. A substrate of the enzyme, 1,2-propanediol, repressed hilA expression. The 1,2-propanediol-mediated repression at 150 mM, but not that at 300 mM, was abrogated by blocking the catabolism producing propionate from 1,2-propanediol.

Bacterial Proteins↗