The production of a mixture of acetic, propionic, and butyric acids is a characteristic feature of alimentary fermentation in the ruminant and in the horse, pig, rabbit, and rat. The proportions of these acids present in the digesta of the large intestine, and of the stomach in the case of the ruminant, is similar in these species, with the exception of the rat, in which acids higher than aceti...

The potential role of a new energy efficient fermentation technology has been receiving growing attention in past 4 decades. Carboxylic acids such as propionic acid, lactic acid, citric acid, tartaric acid, itaconic acid, butyric acid and nicotinic acid etc. have been used as the most efficient fermentation chemicals. This paper presents a state-of-art review on the development of the separatio...

Production of fermented functional foods containing micronutrients is required for their health beneficial properties. The impact of 11 process variables on vitamin B12 production in a dairy beverage containing propionic acid was investigated. Propionibacterium freudenreichii ssp. shermanii was applied in a 3-l fermentor in the fed-batch fermentation system. The most suitable conditions for...

Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type via pH control was investigated. The hydrogen production reached 205.2 mL/g-protein when protein wastewater was pretreated at pH 12 and then fermented at pH 10. The mechanism studies showed that pH 12 pretreatment significantly enhanced protein bio-hydrolysis during the subs...

The potential of recovering propionic acid from discharged water in vitamin B(12) production by anaerobic fermentation was investigated in this paper. A primary amine, N(1923), was used as the extractant, kerosene as diluter and n-octanol as modifier. The influences of the content of N(1923) in the organic phase, the phase ratio and the pH of aqueous phase on the extraction yield of propionic a...

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...

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...