background: the high percentage of consumed antibiotics by humans and animals is excreted with other residues from the body after its performance. by entering these compounds to the wastewater, they can disrupt the anaerobic treatment process. in this study, deterrent behavior of two ampicillin and gentamicin antibiotics are investigated on specific methanogenic activity (sma) of anaerobic biom...

this study was carried out to investigate the effect of esterification on the surface roughness of eastern cottonwood. eastern cottonwood was modified without using any catalyst and solvent at different temperatures and times with two linear chain carboxylic acid anhydrides (acetic anhydride or propionic anhydride). different weight percentage gains (wpgs) were obtained at different conditions....

Factors affecting in vitro ruminal bacterial VFA production were examined. Treatments consisted of high and low initial pH (6.7, 5.7), osmolality (600, 400 mOsm) and concentrations of acetic (40, 0 mM) and propionic acids (20, 0 mM). Response variables measured included the production of acetic, propionic and total VFA, total gas and methane. Initial pH affected (P less than .05) most variables...

Elsden (1945) has shown that the volatile acids in the rumen fluid of sheep are chiefly acetic, propionic, and butyric. Barcroft, MoAnally, and Phillipson (1944) showed that the concentration of volatile acids in the blood draining the rumen was higher than that in the entering blood, indicating absorption from the rumen. Elsden postulated that propionic acid did not arise directly in cellulose...

1. The effects in the cow of intraruminal infusions of acetic acid, propionic acid or butyric acid on the secretion of the component fatty acids of the milk fat, and of these acids and of lactic acid on the composition of the blood plasma of the jugular vein, have been studied. 2. The infusion of acetic acid or butyric acid increased the yield of the C(4)-C(16) acids of milk fat but decreased t...

Biosynthetic pathways of ebelactone A and B were studied by 13C NMR spectroscopy. By using 13C labeled compounds as precursors it was determined that ebelactone A was derived from one molecule of acetic acid and six propionic acids and ebelactone B from one molecule of acetic acid, five propionic acids and one butyric acid.

1. Sheep fed at a constant rate were infused intraruminally with [1-(14)C]-acetate, -propionate or -butyrate during 5hr. periods. 2. Volatile fatty acids were estimated in the rumen contents and steady-state conditions were obtained. 3. Of the butyric acid carbon 60% was in equilibrium with 20% of the acetic acid carbon, and 2-3g.atoms of carbon were interconverted/day. 4. Little interconversio...