this experiment was conducted to determine the effects of propionic acid, formic acid, molasses and molasses plus urea on chemical composition, microbial population, ruminal degradability of dry matter (dm) and crude protein (cp), and aerobic stability of corn silage. prior to ensiling, whole crop corn was chapped and treated with water (control), propionic acid (1%), formic acid (0.8%), molass...

Since acetic acid inhibits the growth and fermentation ability of Saccharomyces cerevisiae, it is one of the practical hindrances to the efficient production of bioethanol from a lignocellulosic biomass. Although extensive information is available on yeast response to acetic acid stress, the involvement of endoplasmic reticulum (ER) and unfolded protein response (UPR) has not been addressed. We...

1. An experiment was conducted using three non-lactating cows completely maintained by infusions of volatile fatty acids into the rumen, and casein into the abomasum. Plasma insulin responses to propionic acid, glucose or casein were recorded. Further information was obtained using protein-free infusions. 2. When part of the propionic acid was infused into the rumen in a twice-daily 3 h dose an...

Two-dimensional gel electrophoretic analysis of the membrane fraction of Acetobacter aceti revealed the presence of several proteins that were produced in response to acetic acid. A 60-kDa protein, named AatA, which was mostly induced by acetic acid, was prepared; aatA was cloned on the basis of its NH2-terminal amino acid sequence. AatA, consisting of 591 amino acids and containing ATP-binding...

I . Glucose, and acetic, propionic and butyric acids, the major energy sources available to ruminants, have been comparatively evaluated as energy sources for growth in lambs. The energy sources wcrc administered intravenously at 2.092 and 2. j 10 MJ metabolizable energy per 24 h for periods of 9-12 d. Nitrogen was given in excess of requirement so that growth rate was limited by energy, as ind...

Previous work has shown that undissociated forms of organic acids, such as formic, acetic, and propionic acids, increase the permeability of barley roots to ions. The work here was undertaken to test whether these undissociated acids affect the lipids from the root membranes in such a way as to account for the permeability increase. Relative amounts of the principal fatty acids from barley root...

The inhibition effects and mechanisms of chlorinated methane and acetylene on methanogenesis in the anaerobic digestion process of the biodegradable wastes were investigated. It was found that both chloroform and acetylene could effectively inhibit methanogens while the biodegradability of the wastes was not affected. Acetylene inhibited the activity of methanogens, while chloroform inhibited m...

A study has been made of the fate of staphylococci and tubercle bacilli resuspended in aqueous media at slightly acid reactions. The tests were carried out at several acid reactions in balanced ionic media containing 0.5 per cent serum albumin. These experimental conditions were selected in order to approximate those which are probably encountered by pathogenic agents in inflammatory areas and ...

BACKGROUND Dietary fibre is fermented by the colonic microbiota to carboxylic acids (CA), with potential health effects associated in particular with butyric and propionic acid. OBJECTIVE To investigate the formation of CA in the hindgut of healthy rats fed dietary fibre from different fractions of wheat shorts, a by-product of the milling of wheat. DESIGN Rats were fed dietary fibre (80 g/...

Four in vitro trials were conducted to determine how ruminal fermentation is affected by source of fat, level of fat, and combinations of fatty acids. Trials I and II examined how volatile fatty acids (VFA) were changed by three sources of fat (blended animal-vegetable fat, corn oil and tallow fatty acids) each added to a hay substrate at six levels (0, 2, 4, 6, 8 and 10%). Increasing blended f...