Mixture Of Propionic Acid Research Articles

Synthetic transformations of higher terpenoids: XXV. Cross coupling of phlomisoic acid methyl ester with alkenes in the presence of oxidants

The reaction of phlomisoic acid methyl ester with styrene, catalyzed by Pd(OAc)2, in the presence of Cu(OAc)2 and 1,4-benzoquinone in a mixture of propionic acid with diethyl ether gave the corresponding 15,16-distyryl derivative and only traces of 15- and 16-monosubstituted furanolabdanoids. Oxidative coupling of the title compound with methyl acrylate under analogous conditions afforded a mixture of 15-mono-, 16-mono-, and 15,16-dialkenylation products whose ratio changed during the process. The reaction was stereoselective, and the exocyclic double bond in the products had exclusively E configuration.

Gas Chromatographic/Mass Spectrometric Analysis of Volatile Metabolites in Bovine Vaginal Fluid and Assessment of Their Bioactivity

The chemical profiles of vaginal fluid collected from cows in oestrus and nonoestrus were analysed by gas chromatography-mass spectrometry (GC-MS) to establish any qualitative differences that might have potential value in bovine biocommunication. Eight different organic compounds were detected using the two chromatograms. The chemical profiles of oestrus vaginal fluid were distinguished significantly by the presence of three specific substances, namely, trimethylamine, acetic acid, and propionic acid that were not present in nonoestrus phase. The oestrus specific synthetic compounds were rubbed onto the genital region of nonoestrus animals (dummy cows), and the bulls were allowed to sniff the genital region and observed sexual behaviours. The statistical significance was higher (P < 0.001) in bulls exhibiting repeated flehmen and mounting behaviours towards the mixture of acetic acid, propionic acid, and trimethylamine as compared to test these compounds separately. It was concluded that the volatile substances present in the bovine vaginal fluid during oestrus may act as chemical communicators.

Effects of maturity stage, wilting and acid treatment on crude protein fractions and chemical composition of whole crop pea silages ( Pisum sativum L.)

In order to determine if maturity stage, and wilting or acid treatment, change the crude protein (CP) fraction distribution (determined according to the Cornell Net Carbohydrate and Protein System) of whole crop pea silages, a pea with variegated flowers ( Pisum sativum ssp. arvense L., cv Timo) was compared to a white-flowered, semi-leafless pea ( P. sativum ssp. hortense L, cv Capella). Herbage was harvested at three maturity stages being: pod set, pod swell and full pod, and either acid-treated or wilted. Timo was acid-treated using 4 (acid4), 6 (acid6) or 8 (acid8) L/tonne fresh matter (FM) with a 2:1 mixture of formic and propionic acid, or wilted to a dry matter (DM) content of about 400 g/kg. Capella was treated with acid6 or wilted. Herbage was ensiled for 103 days in 10 kg laboratory silos. Despite differences in wilting conditions, all wilted herbages had similar protein fraction distributions. In the Capella silages the soluble CP content was lower in the later maturity stages, but this was not the case in the Timo silages. The amount of acid added only affected the B1 CP fraction content, which decreased with increasing acid. At pod set and pod swell for Timo, and at pod set for Capella, the direct-harvested herbages were difficult to ensile because of the high buffering capacity and low level of water soluble carbohydrates. Wilting improved ensilability. Acid treatment reduced proteolysis, but crops with DM contents below 150 g/kg must be acid treated with at least 6 L/tonne FM to ensure stable fermentation. Timo silages were more prone to malfermentation, probably caused by lodging, which made Capella the preferred cultivar for producing pea silages harvested at the pod swell stage or later. Proteolysis and the amount of soluble CP in the silage were lower in later maturity stages in the Capella, but not the Timo, cultivar.

Refractive index, molar refraction deviation and excess molar volume of binary mixtures of 1,4-dioxane with carboxylic acids

The refractive indices and densities of three carboxylic acids viz formic acid (FA), acetic acid (AA) and propionic acid (PA) in 1,4-dioxane (D) over the entire composition range have been measured at 293, 303 and 313 K. Refractive index and density data have been used to evaluate the molar refraction deviation ΔR m and excess molar volume . The values of ΔR m and for all the three binary mixtures have been found to be negative. However, a smaller positive trend in has been observed for the 1,4-D + PA mixture in the D rich region. Values of ΔR m and are more negative in the case of 1,4-D + FA, suggesting that intermolecular interaction is strongest between unlike molecules as compared to the other two binary mixtures. Further, various theoretical mixing rules for the prediction of refractive index of liquid mixtures have been applied to predict the refractive index of these binary mixtures. A critical analysis of these rules from the point of view of their applicability at different temperatures has been carried out.

Thermostimulated processes in starch-bis(hydroxymethyl)propionic acid mixtures subjected to high-pressure plastic deformation

DSC and thermogravimetry are employed to study starch, bis(hydroxymethyl)propionic acid, and their mixtures of different compositions subjected to plastic deformation under pressures of 1 and 3 GPa. An endothermic peak with an enthalpy of 300 J/g observed in the thermogram of starch is most likely related to the breakage of hydrogen bonds. Treatment under pressure greatly reduces the enthalpy of this peak. For initial mixtures, the enthalpies of the endothermic peak of starch and the endothermic peak of melting of the acid are lower than those for individual components because of chemical interaction occurring between the mixture components during heating. The high-pressure treatment makes the decrease in the enthalpy of endothermic processes much more pronounced for both components.

Effect of wilting, silage additive, PEG treatment and tannin content on the distribution of N between different fractions after ensiling of three different sainfoin (Onobrychis viciifolia) varieties

AbstractSainfoin (Onobrychis viciifolia) is a tanniniferous, leguminous plant that has potentially beneficial effects on protein utilization in ruminants. As ensiling causes protein breakdown and elevated levels of buffer soluble N (BSN), we studied the distribution of N before and after ensiling sainfoin. Three varieties of sainfoin were either direct‐cut and frozen directly or wilted and frozen before later ensiling in mini‐silos with and without acidification with Promyr (PM; an acidifying commercial mixture of propionic and formic acid) and with or without polyethylene glycol (PEG). Extractable tannins (ET) and protein‐bound tannins (PBT) were measured with an HCl/butanol method in an attempt to correlate tannin levels to N fractions. The sainfoin silages showed good ensiling characteristics and had relatively high concentrations of undegraded protein. The effect of wilting on BSN levels (g/kg N) was dependent on sainfoin variety (P &lt; 0·001). PEG increased and PM decreased the level of BSN in the silages (P &lt; 0·001). PM treatment also produced less non‐protein N and ammonia‐N (P &lt; 0·05) as compared with no additive. Addition of PEG to the silage increased the BSN‐proportion 1·8‐ and 2·6‐fold for both DM stages. A strong tannin‐protein binding effect is, therefore, confirmed in sainfoin. However, correlations between tannin levels (ET and PBT) and BSN were poor in the (non‐PEG) silages, indicating either that the HCl/butanol method is unsuitable for measuring tannin in silages or that qualitative attributes of tannins are more relevant than quantitative. The HCl/butanol method seems therefore not to be useful to predict degradation of protein in sainfoin silages.

Effect of pH on the production of bacterial polyhydroxyalkanoates by mixed cultures enriched under periodic feeding

This research investigated the effect of pH on polyhydroxyalkanoate (PHA) production by mixed cultures enriched in a sequencing batch reactor (SBR) starting from activated sludge. The enrichment was performed with a mixture of acetic (85% on COD basis) and propionic (15%) acid, at an organic load rate of 8.5 gCOD/L/day over the range of pH from 7.5 to 9.5. The enriched cultures were all able to store the copolymer poly(3-hydroxybutyrate/3-hydroxyvalerate). Higher polymer production rates and yields (389 mg PHA (as COD)/g non-polymer biomass (as COD)/h and 0.53 COD/COD, respectively) were observed when the pH in the SBR was controlled at 7.5, with Lampropedia hyalina as the dominant bacterial species of the microbial community. PHA composition was also strongly affected by the pH. Indeed, batch tests showed that hydroxyvalerate (HV) content in the copolymer increased with increasing pH up to about 48% (mol/mol) at pH 9.5. Interestingly, the possibility of enhancing the HV content was also verified by performing batch tests at a more alkaline pH value than that in the SBR. In conclusion, this paper suggests that pH control is a main tool to tune HV content in the PHA, regardless of the feed composition.

Dielectric and spectrometric investigations of binary mixtures of tetrahydrofuran with propionic acid

The static permittivity (εm ) and the permittivity at the high-frequency limit (ε∞m ) of a binary mixture of propionic acid with tetrahydrofuran (THF) have been determined for different concentrations at temperatures of 303, 308, 313, and 318 K. The data have been used to compute the Kirkwood correlation factor, the excess permittivity, and the excess free-energy of the mixtures. The Kirkwood correlation factor is found to increase with increasing THF concentration. The mixture exhibited positive values of the excess permittivity and negative values of the excess free-energy of mixing, respectively. UV-Vis and FT-IR spectral measurements have also been carried out. The observed bathochromism and hypochromism in the UV-Vis spectra have been explained in terms of complex formation and ordering of dipoles of the complex. The FT-IR spectrum of the mixture shows considerable shifts in the positions of some of the absorption bands, indicating extensive hydrogen bonding between solute and solvent molecules.

Combined effect of amino and carboxyl group in α-alanine on seeded precipitation of sodium aluminate solution

α-alanine was adopted as a new additive to elucidate the seeded precipitation mechanism of sodium aluminate solution. α-alanine has the inhibitory effect at the initial period of reaction, but the favorable effect in subsequent reaction. The combined effect of amino and carboxyl group in α-alanine was confirmed by investigating the effect of propionic acid, ethamine and the mixture of propionic acid and ethamine (mole ratio 1:1) on the precipitation of sodium aluminate solution, respectively. The inhibitory effect derives from the adsorption of amino or carboxyl group in α-alanine on the active surface sites of gibbsite, which was confirmed by the alleviating inhibitory effects of propionic acid, ethamine and α-alanine due to the double crystal seed mass. The semi-quantitative IR spectrum analysis of the relative concentrations of Al 2O(OH) 6 2– with the band at about 550 cm −1 and polynuclear aluminate ion with the bands at about 880 cm −1 and 635 cm −1, indicates that the dynamic balance among some aluminate species present in sodium aluminate solution is broken due to the addition of α-alanine, thus resulting in the change of the seeded precipitation ratio of sodium aluminate solution.

Metabolic modelling of polyhydroxyalkanoate copolymers production by mixed microbial cultures

BackgroundThis paper presents a metabolic model describing the production of polyhydroxyalkanoate (PHA) copolymers in mixed microbial cultures, using mixtures of acetic and propionic acid as carbon source material. Material and energetic balances were established on the basis of previously elucidated metabolic pathways. Equations were derived for the theoretical yields for cell growth and PHA production on mixtures of acetic and propionic acid as functions of the oxidative phosphorylation efficiency, P/O ratio. The oxidative phosphorylation efficiency was estimated from rate measurements, which in turn allowed the estimation of the theoretical yield coefficients.ResultsThe model was validated with experimental data collected in a sequencing batch reactor (SBR) operated under varying feeding conditions: feeding of acetic and propionic acid separately (control experiments), and the feeding of acetic and propionic acid simultaneously. Two different feast and famine culture enrichment strategies were studied: (i) either with acetate or (ii) with propionate as carbon source material. Metabolic flux analysis (MFA) was performed for the different feeding conditions and culture enrichment strategies. Flux balance analysis (FBA) was used to calculate optimal feeding scenarios for high quality PHA polymers production, where it was found that a suitable polymer would be obtained when acetate is fed in excess and the feeding rate of propionate is limited to ~0.17 C-mol/(C-mol.h). The results were compared with published pure culture metabolic studies.ConclusionAcetate was more conducive toward the enrichment of a microbial culture with higher PHA storage fluxes and yields as compared to propionate. The P/O ratio was not only influenced by the selected microbial culture, but also by the carbon substrate fed to each culture, where higher P/O ratio values were consistently observed for acetate than propionate. MFA studies suggest that when mixtures of acetate and propionate are fed to the cultures, the catabolic activity is primarily guaranteed through acetate uptake, and the characteristic P/O ratio of acetate prevails over that of propionate. This study suggests that the PHA production process by mixed microbial cultures has the potential to be comparable or even more favourable than pure cultures.

Use of organic acids mixture as an option to replace antibiotic growth promoters in poultry diets

Antibiotic growth promotion in agricultural animal production has been practiced for about 50 year in the United States and other countries. Early indications were for a beneficial effect on production efficiency in poultry and swine. There were early concerns about the development of antibiotic resistance in human pathogens resulting in recommendations to ban sub therapeutic use in animal feeds. One of the best alternatives for antibiotic growth promoters are organic acids. Organic acids mixtures have been shown to be an effective alternative to eliminate salmonellas in feeds and chickens. Various organic acid combinations were tested to prevent Salmonella contamination through the ration in day-old chicks, and it was observed that a mixture of formic (70%) and propionic acid (30%), was efficient to eliminate S. enteritidis and S. thyphimurium, both of great importance in human health and increase growth rate in broiler.

A rapid microwave induced synthesis of [carboxyl-14C]-nicotinic acid (vitamin B3) and [carbonyl-14C]-nicotinamide using K14CN

Microwave assisted direct aromatic substitution of 3-bromopyridine with K14CN as the cyanide source and catalytic amount of tetrabutylammonium bromide afforded [3-14C]-cyanopyridine 3 in 90% yield. Microwave assisted hydrolysis of 3 with a mixture of concentrated hydrochloric acid and propionic acid afforded [carboxyl-14C]-nicotinic acid in 95% yield whereas microwave assisted hydrolysis of 3 with a mixture of concentrated sulfuric acid and propionic acid afforded [carbonyl-14C]-nicotinamide in 85% yield.

Effects of weaning age and formic acid-based feed additives on pigs from weaning to slaughter

Two hundred and forty piglets were used in a 2×6 factorial experiment to study the effects of weaning age (26 or 36 d) and four formic acid-based feed additives on the performance of pigs from weaning to slaughter. Either formic acid (F) or a mixture of formic acid, propionic acid, and potassium sorbate (FPS) or a mixture of formic acid, propionic acid, and sodium benzoate (FPB) or formic acid in a diatomaceous earth carrier (FD) were added to the diets of weaned piglets (from weaning to 60 d of age) and growing (18 – 46 kg) and finishing pigs (46 – 107 kg) to provide 8, 6, and 6 g acid per kg feed, respectively. The negative control treatment's (C) diets contained no growth promoters, whereas the positive control treatment's weaner and grower diets were supplemented with 40 mg/kg of avilamycin (A). The piglets weaned at the age of 26 and 36 d weighed 7.6 and 10.7 kg at weaning (p < 0.001), and 18.5 and 17.9 kg at the age of 60 d (p > 0.05), respectively. There was a weaning age×feed additive interaction in the weight gain of piglets after weaning (p < 0.05). The weight gain of piglets weaned on day 26 was enhanced by A, FPS, and FD (p < 0.05), and that of piglets weaned on day 36 by A and FPB (p < 0.05). The feed conversion ratio was not affected by weaning ages but was decreased in groups A, F, FBS, and FPB (p < 0.05). The severity of post-weaning diarrhoea was less in groups A, F, FPS, and FD than in C (p < 0.05). In piglets weaned on day 26, faecal water content and the total Escherichia coli count were highest 9 d after weaning. The total E. coli count was reduced only by FD (p < 0.05). Increased faecal water content was characterized by increased faecal Na+ and decreased K+ concentrations. Weaning age did not influence performance or carcass quality in the growing-finishing pigs. Feed additives did not affect weight gain in the growing pigs, but FPS and FPB enhanced weight gain during finishing period and total fattening (p < 0.05). In summary, the pigs' growth performance from weaning to slaughter was not affected by weaning age but it was enhanced by mixtures of formic and propionic acids with small amounts of sorbate or benzoate.

The effect of volatile fatty acids on the inactivation of Clostridium perfringens in anaerobic digestion

The application of sludge digestion systems to remove pathogens has been employed to generate biosolids suitable for reuse in agriculture. Traditionally, temperature is considered the principal agent responsible for pathogen reduction in anaerobic digestion. However, other substances such as volatile fatty acids may also have an antimicrobial effect. The objective of this study was to assess the impact of fatty acid mixtures on the inactivation of C. perfringens over a range of digestion temperatures. An equimolar mixture of acetic acid, propionic acid and butyric acid was applied to digester effluent for a period of 24 h at temperatures of 35 °C, 42 °C, 49 °C and 55 °C. C. perfringens inactivation in digester effluents, when dosed with volatile organic acids, was found to depend on pH, acid concentration and temperature. Temperatures above 55 °C appeared to increase the inhibitory effects of the organic acids at higher concentrations. An interaction between temperature and pH on survival of C. perfringens was observed. The results suggest that high concentrations of organic acids at a pH value of 4.5–5.5 during thermophilic digestion substantially reduce concentrations of C. perfringens in municipal sludge.

Production and characterization of terpolyester poly(3-hydroxybutyrate- co-3-hydroxyvalerate- co-3-hydroxyhexanoate) by recombinant Aeromonas hydrophila 4AK4 harboring genes phaAB

Recombinant Aeromonas hydrophila 4AK4 harboring phbA and phbB ( phaAB) genes encoding β-ketothiolase and acetoacetyl-CoA reductase of Ralstonia eutropha produced a terpolyester of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 3-hydroxyhexanoate (3HHx) [P(3HB- co-3HV- co-3HHx)] from mixtures of dodecanoic acid and propionic acid. Depending on the concentration of propionic acid in bacterial cultures, cell growth represented by cellular dry weight (CDW), P(3HB- co-3HV- co-3HHx) contents in dry cells and 3HV molar percentage in the terpolyester ranged from 0.43 g l −1 to 3.29 g l −1, 20.7% to 35.6%, 2.3 mol% to 7.1 mol%, respectively. Number average molecular ( M n) weights of the terpolyesters were 303,000–800,000, independent from monomer fraction content. This terpolyester was characterized by nuclear magnetic resonance (NMR), gel-permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and stress–strain measurement studies. Results showed that the terpolyester had higher thermal stability and elongation at break compared with that of homopolymer poly(3-hydroxybutyrate) (PHB) and its copolymers P(3HB- co-5 mol%3HV) or P(3HB- co-12 mol%3HHx). In addition, the terpolyester had lower melting ( T m) temperatures and enthalpy of fusions (Δ H m) than PHB did.

Identification of putative pheromones in bovine ( Bos taurus) faeces in relation to estrus detection

Ten different volatile compounds were detected in bovine faeces using three chromatograms. The chemical profiles of estrus faeces were distinguished significantly from other phases by the presence of three specific substances, viz. acetic acid and propionic acid and 1-iodo undecane. The estrus specific synthetic compounds were rubbed onto the genital region of nonestrus animals (dummy cows), and the bulls were allowed to sniff the genital region and observed sexual behaviours. The statistical significance was higher ( P < 0.001) in bulls exhibiting repeated flehmen and mounting behaviours towards the mixture of acetic acid, propionic acid and 1-iodo undecane. The bioassay revealed that the fatty acids viz., acetic acid; propionic acid and 1-iodo undecane produced in faeces during estrus appear to be estrus specific. The results suggest that these compounds may be used as estrus indicator in cow, probably involved in bovine biocommunication.

A sol–gel route for the development of rare-earth aluminum borate nanopowders and transparent thin films

A new sol–gel route was applied to obtain Y 0.9Er 0.1Al 3(BO 3) 4 crystalline powders and amorphous thin films by using Al(acac) 3, B(OPr i ) 3, Y(NO 3) 3·6H 2O, and Er(NO 3) 3·5H 2O as starting materials dissolved in propionic acid and ethyl alcohol mixtures. Our study shows that propionic acid acts as good chelant agent for yttrium and erbium ions while ethyl alcohol allows to dissolve Al(acac) 3. This process makes the resulting sols very stable to obtain homogeneous gels and transparent amorphous thin films. In addition, the propionic acid prevents the sol precipitation, making easy porous- and crack-free thin film depositions. Chemical reactions involved in the complexation were discussed. As-prepared powders and films are amorphous and present a good thermal stability due to their high glass transition (746 °C) and crystallization temperatures (830 °C). This new sol–gel route showed to be adequate to obtain dense and crack-free thin films free of organic and hydroxyl groups that can be considered as promising materials to be used in integrated optical systems.

Effects of stage of maturity and conservation strategy on fermentation, feed intake and digestibility of whole-crop pea-oat silage used in dairy production

In two repeated 3×3 Latin Square design trials, dairy cows have been fed bi-crop pea-oat silage to investigate the effect of maturity stage and harvest strategy on feed intake and milk production. In experiment 1 the crop was harvested when the peas were at the flat pod (cut 1) or full pod (cut 2) stage. At the first cut half of the forage was wilted and half was acid-treated with a 2:1 mixture of formic and propionic acid. At the second cut all of the forage was acid-treated. Voluntary intake was highest for the cut 2 silage. In experiment 2 the crop was harvested when the peas were at the flat pod (cut 1), pod fill (cut 2) or full pod (cut 3) stage. The crop was pre-wilted overnight and then acid-treated. Voluntary intake was highest for the cut 3 silage, although the in vivo apparent digestibility was lowest. Milk and protein yield increased with crop maturity. It was concluded that pre-wilting and acid treatment produces good quality, palatable pea-oat bi-crop silage. In terms of feed intake and milk production, the optimal time of harvest was when peas were at the pod fill stage and the oats were in the late milk to early dough stage.

Solvent nature effect in preparation of perovskites by flame pyrolysis: 2. Alcohols and alcohols + propionic acid mixtures

The effect of either pure alcohols or alcohols+propionic acid mixtures as solvents for the preparation by flame pyrolysis of a standard LaCoO3 catalyst, to be employed for the catalytic flameless combustion of methane, has been investigated. All the catalysts proved very active for the mentioned reaction. Low-MW pure alcohols showed however less suitable than alcohols-propionic acid mixtures, leading to lower perovskite phase purity, less particle size homogeneity and lower specific surface area. The high volatility of the solvent seems to be the major cause, together with the improper behaviour of nitrates (forced by solubility reasons) as perovskite metals precursors. However, the addition of propionic acid to the alcohols allowed to use the acetates as precursors and hence to obtain high perovskitic phase purity, high SSA and uniform particle size. Moreover, the increase of combustion enthalpy of the solvent, through the addition of higher-MW alcohols, leading to progressively higher flame temperature, strongly improved the thermal resistance of the catalyst, without lowering catalytic performance.

Opinion of the Panel on additives and products or substances used in animal feed (FEEDAP) on the safety and efficacy of Kofa®Grain -pH 5- (a mixture of sodium benzoate, propionic acid and sodium

Opinion of the Panel on additives and products or substances used in animal feed (FEEDAP) on the safety and efficacy of Kofa®Grain -pH 5- (a mixture of sodium benzoate, propionic acid and sodium