[Determination of free volatile fatty acids in VI medium following growth of anaerobic bacteria].
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Anaerobiosis↗
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Results for “Fatty Acids, Volatile”
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[Content of volatile fatty acids in various kinds of butter].
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Butter↗
[Secretory rate of volatile fatty acids in sheep's omasum as a function of different starch and sugar contents in their feed].
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Animal Feed↗
Normal abomasal electromyography and emptying in sheep and the effects of intraabomasal volatile fatty acid infusion.
Electromyographic activity and emptying of the abomasum were studied in 3 sheep. Pacesetter potentials (PP), with a frequency of 6.06 +/- 0.05 (X +/- SEM) cycles/minute and propagated distally with an increased conduction velocity approaching the pylorus, were recorded from the distal 11 cm of the antrum. Spike burst and fused action potentials (AP) were superimposed on a variable percentage of PP. The aborad propagation of both types of AP was associated with abomasal emptying at the net rate of 12.61 +/- 1.38 (X +/- SEM) ml/minute. Intraabomasal infusion of 50 ml of a 300 mM solution of either acetic, propionic, or butyric acid was associated with a marked decrease in abomasal AP activity and in the emptying rate. Butyric acid was most effective, followed by propionic and acetic acids. The importance of the results in relation to the pathogenesis of left displaced abomasum (LDA) in dairy cows was noted.
Abomasum↗
Estimation of the stoichiometry of volatile fatty acid production in the rumen of lactating cows.
The purpose of this study was to improve the prediction of the quantity and type of Volatile Fatty Acids (VFA) produced from fermented substrate in the rumen of lactating cows. A model was formulated that describes the conversion of substrate (soluble carbohydrates, starch, hemi-cellulose, cellulose, and protein) into VFA (acetate, propionate, butyrate, and other VFA). Inputs to the model were observed rates of true rumen digestion of substrates, whereas outputs were observed molar proportions of VFA in rumen fluid. A literature survey generated data of 182 diets (96 roughage and 86 concentrate diets). Coefficient values that define the conversion of a specific substrate into VFA were estimated meta-analytically by regression of the model against observed VFA molar proportions using non-linear regression techniques. Coefficient estimates significantly differed for acetate and propionate production in particular, between different types of substrate and between roughage and concentrate diets. Deviations of fitted from observed VFA molar proportions could be attributed to random error for 100%. In addition to regression against observed data, simulation studies were performed to investigate the potential of the estimation method. Fitted coefficient estimates from simulated data sets appeared accurate, as well as fitted rates of VFA production, although the model accounted for only a small fraction (maximally 45%) of the variation in VFA molar proportions. The simulation results showed that the latter result was merely a consequence of the statistical analysis chosen and should not be interpreted as an indication of inaccuracy of coefficient estimates. Deviations between fitted and observed values corresponded to those obtained in simulations.
Acetates↗
Effects of live yeast on the performance, nutrient digestibility, gastrointestinal microbiota and concentration of volatile fatty acids in weanling pigs.
Two experiments were conducted to evaluate the effects of live yeast supplementation on performance, nutrient digestibility, enteric microbial populations and volatile fatty acid (VFA) concentration of weanling pigs, receiving diets supplemented with aureomycin and elevated doses of CuSO4. In experiment 1, 90 crossbred pigs (7.20 +/- 0.44 kg, 28 d of age) were randomly allotted to one of five dietary treatments containing either 0, 4.0 x 10(6), 9.0 x 10(6), 2.6 x 10(7), or 5.1 x 10(7) cfu Saccharomyces cerevisiae per gram with six replicate pens per treatment and three pigs per pen. BWG and feed intake increased quadratically during days 1-14 and days 1-28 as live yeast levels increased (p < 0.01). Pigs fed the diet containing 2.6 x 10(7) cfu yeast per gram had the highest BWG and feed intake among the treatments. In experiment 2, 48 crossbred pigs (7.64 +/- 0.72 kg, 28 d of age) were fed diets containing live yeast at 0 or 3.2 x 10(7) cfu of S. cerevisiae per g with six replicate pens per treatment and four pigs per pen. The yeast supplementation improved BWG and feed intake during days 1-14 (p < 0.01) and days 1-28 (p < 0.05). Treatment differences were not observed in any of the bacterial populations, yeast numbers or VFA concentrations, at any of the sites of the gastrointestinal tract tested. Total tract nutrient digestibility was also not different between treatments. Overall, dietary supplementation of live yeast had a positive effect on BWG and feed intake of weanling pigs, receiving diets supplemented with aureomycin and elevated doses of CuSO4. The improvement in BWG appears to be partly related to an increase in feed intake. The mechanism of yeast improving feed intake of piglets needs to be explored.
Animal Feed↗
Metabolic function of branched-chain volatile fatty acids, growth factors for ruminococci. II. Biosynthesis of higher branched-chain fatty acids and aldehydes.
Allison, M. J. (Dairy Cattle Research Branch, USDA, Beltsville, Md.), M. P. Bryant, I. Katz, and M. Keeney. Metabolic function of branched-chain volatile fatty acids, growth factors for ruminococci. II. Biosynthesis of higher branched-chain fatty acids and aldehydes. J. Bacteriol. 83:1084-1093. 1962.-A number of strains of rumen bacteria require branched-chain volatile fatty acids for growth. A strain of Ruminococcus flavefaciens that requires either isovalerate or isobutyrate incorporates radioactive carbon from isovalerate-1-C(14) and isovalerate-3-C(14) into leucine and into the lipid fraction of the cells. Evidence obtained by both paper and gas chromatography indicated that most of the label in the lipid of cells grown in isovalerate-1-C(14) was in a branched-chain 15-carbon fatty acid, with some in a 17-carbon acid; about 7.5% of the C(14) was recovered in a branched-chain 15-carbon aldehyde. The aldehydes were in the phospholipid fraction and were presumably present as plasmalogen.A strain of R. albus was shown to require isobutyrate, 2-methyl-n-butyrate, or 2-ketoisovalerate for growth. This strain did not incorporate appreciable C(14) from isovalerate-1-C(14) or isovalerate-3-C(14). When grown in a medium containing isobutyrate-1-C(14), most of the cellular C(14) was found in the lipid fraction. Analysis of the lipid demonstrated that the label was present mainly as branched-chain 14-carbon and 16-carbon fatty acids, with 11% of the C(14) present in 14- and 16-carbon carbonyl compounds, presumably branched-chain aldehydes.Branched-chain 14-, 15-, and 16-carbon fatty acids are major components of the lipids of these rumen bacteria. The possibility that these acids and aldehydes, which are found in ruminant body and milk lipids, may be of microbial origin is discussed.
Aldehydes↗
Roles of pH in biologic production of hydrogen and volatile fatty acids from glucose by enriched anaerobic cultures.
Batch experiments were carried out to study the roles of pH in the biologic production of hydrogen and volatile fatty acids from glucose by enriched anaerobic cultures. The results showed that 95-99% of glucose in wastewater was acidified at 30 degrees C and pH 4.0-8.5. Hydrogen yield fluctuated between 1.30 and 1.57 mol of H2/mol of glucose when the reactor was operated at pH 4.0-5.0. However, a further increase in pH led to a considerable decrease in hydrogen yield, especially for the cases at pH 7.5 and 8.0. Acetate, propionate, butyrate, and ethanol were the key products of acidogenesis. Production of butyrate was favored at pH 4.0-5.0, whereas production of acetate was favored at pH 6.0-8.0. A modified Gompertz equation is able to properly describe the batch production of hydrogen from glucose. The optimum pH for the specific hydrogen production was found to be 5.5, close to 5.7, the optimum pH calculated using a semiempirical model.
Bacteria, Anaerobic↗
The role of poly-hydroxy-alkanoate form in determining the response of enhanced biological phosphorus removal biomass to volatile fatty acids.
Anaerobic-aerobic batch experiments indicated that poly-hydroxy-alkanoate (PHA) form was important in determining the net phosphorus removal resulting from different volatile fatty acids (VFAs). Poly-3-hydroxy-butyrate (3HB) content was found to correlate fairly well with higher observed aerobic phosphorus uptake per unit PHA carbon degraded. Poly-3-hydroxy-valerate (3HV) correlated with lower aerobic phosphorus uptakes per unit PHA carbon degraded. These experiments, conducted with synthetic wastewater, imply that VFA speciation might have a significant effect on aerobic phosphorus uptakes and net phosphorus removal. In addition, the model parameter fP.UPT (Barker and Dold, 1997) could vary with the proportion of acetic to propionic acid received (i.e., the acetic/propionic acid ratio may be an important parameter for these systems). Carbohydrate data implied that the lower aerobic phosphorus uptake resulting from 3HV might have been caused by a greater fraction of PHA carbon shunting to carbohydrate biosynthesis during aerobiosis.
Acetic Acid↗
Passive diffusion technique for concentration of short-chain volatile Fatty acids from seawater.
A diffusion chamber is described which concentrates short-chain, volatile fatty acids from seawater while simultaneously separating them from interfering salts. The procedure relies on the passive diffusion of volatile compounds from acidified seawater samples and their subsequent absorption onto a base-impregnated filter. The method is simple, efficient, and adaptable to most commonly used methods of volatile acid analysis.
Journal Article↗
Volatile fatty acid concentrations in the digestive tract of the West Indian manatee, Trichechus manatus.
1. Digesta samples were collected from five West Indian manatees, Trichechus manatus, for volatile fatty acid (VFA) analysis. 2. Mean total VFA concentrations were low in the stomach and duodenum (18.6 and 12.3 mM/l, respectively). Mean VFA concentrations were considerably higher in the cecum and colon (220.6 and 307.3 mM/l, respectively). 3. The relative proportions of the individual VFA's shifted from predominantly acetic acid in the foregut to a mixture of acetic, butyric and propionic acids in the hindgut. 4. The VFA concentrations in the manatee are similar to those in the dugong, Dugong dugon, and the green sea turtle, Chelonia mydas. 5. The mean total VFA concentrations indicate that the cecum and colon of the manatee are sites of microbial cellulose fermentation. The contribution of VFAs to the manatees' total energy requirements could not be calculated, but it is probably considerable.
Animals↗
Monensin and dichloroacetamide influences on methane and volatile Fatty Acid production by rumen bacteria in vitro.
The effect of monensin (0 or 33 mug/g of diet) upon rumen fermentation in the presence and absence of methanogenesis was determined in vitro by using mixed rumen organisms continuously cultured for 17 days. Methane was inhibited by dichloroacetamide (DCA; 32 mg/day) or by a pH of 5.1. Monensin effected a significant decrease in the ratio of acetic to propionic acid in the presence or absence of methanogenesis. In the absence of methanogenesis, the decrease in the ratio of acetic to propionic acid was entirely the result of increased propionic acid, whereas in the presence of methanogenesis the decrease in the ratio was the result of a combination of decreased acetic acid and increased propionic acid. There was a complementary interaction between monensin and DCA on volatile fatty acid production (expressed as millimoles of carbon per day). Addition of monensin to DCA-treated cultures resulted in the production of more acid; however, monensin and DCA had no beneficial effect on total carbon formed as acid and gases as compared with nonsupplemented control cultures. The monensin and DCA also resulted in greater digestion of neutral detergent fiber and less accumulation of formic acid and hydrogen as end products than did DCA alone. l-Lactic acid was produced in small but significantly greater amounts by the low-pH cultures, which also had less volatile fatty acid carbon formed from the fiber fraction of the forage supplied.
Journal Article↗
[Determination of volatile fatty acids in the blood plasma of cattle before and after an infusion of propionate and butyrate].
Before and after infusion of propionate and butyrate the concentrations of volatile fatty acids (VFA) in the blood of heifers were determined by gas chromatography, in order to indicate activity and regulation of the carbohydrate metabolism. 14 heifers were loaded after food deprivation with intravenous infusions of propionate and butyrate. Concentrations of acetate, propionate, isobutyrate, butyrate, and valerate were measured in blood samples which were taken later on. The methods used for clearance and extraction as well as for gas chromatographic analysis are described. Retention times and blood concentrations are given for each VFA. Concentrations prior to infusion were for: acetate 10.14 +/- 2.51 microliters/ml; propionate 0.42 +/- 0.35 microliters/ml; iso-butyrate 3.72 +/- 1.37 microliters/ml; butyrate 3.44 +/- 0.68 microliters/ml blood plasma. The concentrations of the infused VFA showed a 100 (butyrate) to 1000 (propionate) fold increase followed by a subsequent decrease to the initial values. These investigations on the profile of VFA elucidated criteria of the energy metabolism.
Animals↗
Studies on the metabolic function of branched-chain volatile fatty acids, growth factors for ruminococci. I. Incorporation of isovalerate into leucine.
Allison, Milton J. (Dairy Cattle Research Branch, U. S. Department of Agriculture, Beltsville, Md.), M. P. Bryant, and R. N. Doetsch. Studies on the metabolic function of branched-chain volatile fatty acids, growth factors for ruminococci. I. Incorporation of isovalerate into leucine. J. Bacteriol. 83:523-532. 1962.-Ruminococcus flavefaciens strain C94, a cellulolytic rumen bacterium, requires either isobutyrate or isovalerate for growth. The organism was grown in the presence of C(14)-labeled isovalerate, and the metabolic fate of the labeled carbon was studied to obtain information on the functions of this growth factor. Radioactivity from isovalerate-1-C(14) and isovalerate-3-C(14) was found mainly in the protein and lipid fractions of the cells. The C(14) in protein was all in leucine, indicating that a function of isovalerate was to serve as a carbon skeleton for leucine synthesis. As C(14) in leucine synthesized from isovalerate-1-C(14) was entirely in carbon 2, the intact isovalerate molecule was apparently incorporated into leucine. This is evidence that leucine was synthesized by a mechanism different from that previously demonstrated in other microorganisms.R. flavefaciens has a definite but limited ability to incorporate exogenous amino acids, including leucine. It incorporated 2% of the C(14) during growth in uniformly labeled (UL) C(14)-Chlorella protein hydrolyzate; Escherichia coli incorporated 37% of the label under similar conditions. In another experiment, a limited amount of exogenous leucine-2-C(14) was incorporated into protein of R. flavefaciens. The requirement for isovalerate was not replaced by dl-leucine or 2-ketoisocaproate. It is suggested that isovalerate or isobutyrate is required because R. flavefaciens has a limited ability to incorporate exogenous branched-chain amino acids and a limited ability to synthesize the isopropyl group found in these amino acids and in other components of the cell.
Amino Acids↗
Effects of enzyme supplementation on performance, nutrient digestibility, gastrointestinal morphology, and volatile fatty acid profiles in the hindgut of broilers fed wheat-based diets.
A growth trial and a metabolism trial were conducted as 2 experiments to investigate the effects of dietary enzyme supplementation (primarily xylanase and beta-glucanase) on performance, nutrient digestibility, intestinal morphology, digestive organ size, and volatile fatty acid profiles in the hindgut of broiler chickens fed wheat-based diets. The experimental diets in both trials consisted of a wheat-based control diet supplemented with 0, 200, 400, 600, 800, or 1,000 mg/kg enzyme. Diets were given to the birds from d 7 to 42 of age. In the growth trial, enzyme supplementation improved performance of the broilers; daily gain and feed conversion increased linearly (P < 0.01) with increasing levels of enzyme supplementation. Enzyme inclusion decreased the size of the digestive organs and the gastrointestinal tract to some extent. The relative length of each intestinal segment decreased linearly (P < 0.05). The relative weight of the anterior intestine on d 21 and ileum on d 42 also decreased linearly (P < 0.01). On d 21 and 42, there were negative linear (P < 0.05) relationships between increasing enzyme supplementation and the relative weight of the liver and pancreas, respectively. Furthermore, there was a linear (P < 0.01) increase in total volatile fatty acid content in ileum on d 21 and in the cecum on d 21 and 42. During each period of the metabolism trial, apparent crude protein digestibility increased linearly (P < 0.05), whereas no differences were detected (P > 0.05) in AME.
Aging↗
Optimization of glutamate concentration and pH for H production from volatile fatty acids by Rhodopseudomonas capsulata.
AIMS: This study attempted to employ response surface methodology (RSM) to evaluate the effects of glutamate concentration and pH on H(2) production from volatile fatty acids by Rhodopseudomonas capsulata. METHODS AND RESULTS: A mixture of acetate, propionate and butyrate was used as a carbon source for the H(2) production by R. capsulata. The H(2) yield and H(2) production rate were strongly affected by the glutamate concentration, pH and their interaction. The predicted maximum H(2) yield of 0.534 was obtained when glutamate concentration and pH were 6.56 mmol l(-1) and 7.29 respectively. On the contrary, the maximum H(2) production rate of 18.72 ml l(-1) h(-1) was achieved at a glutamate concentration of 7.01 mmol l(-1) and pH 7.31. CONCLUSIONS: Taking H(2) yield and H(2) production rate together into account, a glutamate concentration of 6.56-7.01 mmol l(-1) and pH of 7.29-7.31 should be selected for H(2) production from a mixture of acetate, propionate and butyrate by R. capsulata. SIGNIFICANCE AND IMPACT OF THE STUDY: The RSM was a useful tool for maximizing H(2) production by photosynthetic bacteria (PSB).
Acetic Acid↗
Effect of administration of Lactobacillus crispatus, Clostridium lactatifermentans and dietary lactose on the development of the normal microflora and volatile fatty acids in the caeca of broiler chicks.
1. Lactobacillus crispatus and Clostridium lactatifermentans, both isolated from the caeca of chickens, grown together in an in vitro model system are able to ferment lactose to acetate and propionate. In this study, the capabilities of these organisms were studied in vivo. 2. The effect on concentrations of volatile fatty acids and lactate, together with the development of some bacterial groups in the caeca of chicks, was studied after oral inoculation with L. crispatus and C. lactatifermentans together with dietary lactose. For this purpose, chicks were divided into 4 groups: (i) control group, (ii) dietary lactose, (iii) L. crispatus and C. lactatifermentans, and (iv) dietary lactose together with L. crispitaus and C. lactatifermentans. 3. In general, concentrations of (undissociated) volatile fatty acids in the caeca were not significantly different in broilers receiving both bacteria and dietary lactose compared with control broilers. Concentrations of lactate in the caeca of 14-d-old broilers treated with any of the three treatments were significantly higher than in the caeca of control broilers. 4. This indicates that L. crispatus or other lactate-producing organisms were responsible for the elevated concentrations of lactic acid. Clostridium lactatifermentans has probably not colonised the caeca sufficiently to ferment this lactate further to acetate and propionate. 5. Numbers of Enterobacteriaceae and enterococci in the caeca of broilers receiving both bacteria and dietary lactose were not different from control broilers. 6. We conclude from these results that under the conditions applied in this study a mixture of L. crispatus and C. lactatifermentans with dietary lactose was able to increase lactate concentrations but was unable to increase concentrates of acetate and propionate in the caeca of broiler chicks.
Animals↗
[The use of partly-hydrolyzed and untreated straw meal in the feeding of breeding sows. 5. Concentration, production and absorption of volatile fatty acids in the large intestine].
In 2 experiments with a total of 28 breeding sows of the country species studies were made of the fermentation, production and absorption of volatile fatty acids (VFA) in the large intestine after feeding variously treated straw materials in concentrate--straw meal mixtures. Experiment 1 ascertained that supplements of untreated (I), HCl treated (II) and partly hydrolysed straw meal (III, treatment with subsequent steaming) caused a decrease of the VFA concentration as well as considerable molar changes of the VFA in the caecal and colonal digesta in comparison of the sole feeding with concentrate (IV). The straw fibre integration increased the molar acetate quota at the expense decreased propionate and butyrate fermentation. Considering the straw meal variants this effects was least distinct after the feeding of partly hydrolysed straw meal (III). In experiment 2, which comprised the simultaneous ascertainment of VFA production in the feeding variants I and III and which was based on a representative number of animals per test group (n = 10), there were significant differences between the production quotas (I = 992; III = 1,300 mmol/animal.d) and in the absorption quotas of VFA (I = 63; II = 78%). The digestible energy from the VFA in the large intestine amounted to 711 kJ/d (I) and 1,183 kJ/d (III). The derived higher net energy gain from the hydrolysed straw product (III) was calculated at 590 kJ (40EFUpig/kg DM) and discussed together with results of feed value increase from the digestibility experiments.
Animal Feed↗