Sodium propionate

About: Sodium propionate is a research topic. Over the lifetime, 463 publications have been published within this topic receiving 9451 citations. The topic is also known as: E281 & sodium propionate anhydrous.

Reductive Carboxylation of Propionate to Butyrate in Methanogenic Ecosystems

Abstract: During the batch degradation of sodium propionate by the anaerobic sludge from an industrial digestor, we observed a significant amount of butyrate formation. Varying the initial propionate concentrations did not alter the ratio of maximal butyrate accumulation to initial propionate concentration within a large range. By measuring the decrease in the radioactivity of [1-14C]butyrate during propionate degradation, we estimated that about 20% of the propionate was converted to butyrate. Labeled butyrate was formed from [1-14C]propionate with the same specific radioactivity, suggesting a possible direct pathway from propionate to butyrate. We confirmed this hypothesis by nuclear magnetic resonance studies with [13C]propionate. The results showed that [1-13C]-, [2-13C]-, and [3-13C]propionate were converted to [2-13C]-, [3-13C]-, and [4-13C]butyrate, respectively, demonstrating the direct carboxylation on the carboxyl group of propionate without randomization of the other two carbons. In addition, we observed an exchange reaction between C-2 and C-3 of the propionate, indicating that acetogensis may proceed through a randomizing pathway. The physiological significance and importance of various metabolic pathways involved in propionate degradation are discussed, and an unusual pathway of butyrate synthesis is proposed.

Studies on the control of gluconeogenesis in sheep: effect of propionate, casein and butyrate infusions

Abstract: 1. Short-term effects of infusions of propionate, amino acids and butyrate on gluconeogenesis, as indicated by changes in the irreversible loss of plasma glucose, synthesis of glucose from ruminal propionate or fixation of blood bicarbonate into glucose have been examined in sheep given their daily ration in twenty-four equal portions at hourly intervals.Sheep received intravenous infusions of [6-3H]glucose usually, in combination with [U-14C]glucose or NaH14CO3 or with intraruminal infusions of [2-14C]propionate. Substrates were infused over a 3–7 h period and followed estimates of pre-infusion kinetic measurements.2. It was demonstrated that intraruminal and intramesenteric vein infusions of sodium propionate and intra-abomasal infusions of casein hydrolysate stimulated gluconeogenesis. Glucose synthesis showed a linear response to the infusion of these substrates, which varied from 0·35–6·35 mmol propionate/min and 50–160 mg casein/min.3. The increment in the measured production rate of propionate in the rumen was consistently less than the rate of addition of propionate to the rumen.4. Intramesenteric vein infusions of sodium butyrate at successive rates of 0·25 and 0·50 mmol/min produced only an initial transient increase in plasma glucose production. Since the rate of glucose synthesis from ruminal propionate was not altered, it was suggested that butyrate initiated glycogen mobilization.

Biosynthesis of novel terpolymers poly(lactate-co-3-hydroxybutyrate-co-3-hydroxyvalerate)s in lactate-overproducing mutant Escherichia coli JW0885 by feeding propionate as a precursor of 3-hydroxyvalerate.

Abstract: Novel lactate (LA)-based terpolymers, P[LA-co-3-hydroxybutyrate(3HB)-co-3-hydroxyvalerate(3HV)]s (PLBVs), were produced in LA-overproducing mutant, Escherichia coli JW0885, which was found to be a superior host for the efficient production of LA-based polyesters. Recombinant E. coli JW0885 harboring the genes encoding LA-polymerizing enzyme (Ser325Thr/Gln481Lys mutant of polyhydroxyalkanoate synthase from Pseudomonas sp. 61-3) and three monomer supplying enzymes [propionyl-CoA transferase, β-ketothiolase, and nicotinamide adenine dinucleotide phosphate (reduced form) (NADPH)-dependent acetoacetyl-CoA reductase] was aerobically grown on glucose with feeding of propionate as a precursor of 3-hydroxyvaleryl-CoA (3HV-CoA). Gas chromatography and nuclear magnetic resonance (NMR) analyses revealed that polymers accumulated in the cells were composed of LA, 3HB, and 3HV units, thus being identified as terpolymers, PLBVs. In addition, 1H-NMR analysis suggested the existence of LA-3HV sequence in the terpolymer. When 100 mg/l of sodium propionate was added into the medium, 3HV fraction in the terpolymer linearly reached up to 7.2 mol%, while LA fraction was inversely decreased. This phenomenon could be due to the change in metabolic fluxes of lactyl-CoA (LA-CoA) and 3HV-CoA depending on the concentration of propionate fed into the medium.

Rapid determination of the elevated Na(+)-H+ exchange in platelets of patients with essential hypertension using an optical swelling assay.

Abstract: Accumulating evidence suggests an increased activity of the Na(+)-H+ exchanger in essential hypertension. The present investigation aimed at developing a test for routine measurements. Platelet-rich plasma was added directly to a cuvette placed into an aggregometer containing 140 mmol/l sodium propionate medium (pH 6.7, 37 degrees C). The accumulation of intracellular sodium due to activation of Na(+)-H+ exchange results in an osmotic cell swelling, which is detectable as a decrease in optical density (OD). This reaction reflects activation of the Na(+)-H+ exchanger since we observed (1) a dose-dependent inhibition by amiloride (inhibition constant, Ki = 10 mumol/l) and ethylisopropylamiloride (Ki = 0.07 mumol/l) and (2) a dependence on extracellular sodium of the OD changes. Electron microscopy of sodium propionate-treated platelets revealed a general swelling and a distinct decrease in electron density of the cytosol without other significant alterations. Quantification of Na(+)-H+ exchange activities was accomplished by calculating rate constants of the recorded changes in OD. Application of this assay to 20 essential hypertensives and 32 normotensives demonstrated an increased activity of the Na(+)-H+ exchanger in essential hypertensives (rate constants 29.8 x 10(-3) per s versus 21.7 x 10(-3) per s).