Plasmids are self-replicating genetic elements capable of mobilization between different hosts. Plasmids often serve as mediators of lateral gene transfer, a process considered to be a strong and sculpting evolutionary force in microbial environments. Our aim was to characterize the overall plasmid population in the environment of the bovine rumen, which houses a complex and dense microbiota th...

The objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. The animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. The rumen fluid was obtained through the rumen fistula and immediately was inoculated 100 μL in mineral medium added with 20 mmol L(-1) sodium fluoroacetate (SF), incubated a...

Proteolytic activity of the bovine rumen microflora was studied with azocasein as the substrate. Approximately 25% of the proteolytic activity of rumen contents was recovered in the strained rumen fluid fraction, and the balance of the activity was associated with the particulate fraction. The proportion of proteinase activity associated with particulate material decreased when the quantity of ...

Nisin, a bacteriocin, is a potential alternative to antibiotics to modulate rumen fermentation. However, little is known about its impacts on rumen microbes. This study evaluated the effects of nisin (1 and 5 μM) on in vitro rumen fermentation characteristics, microbiota, and select groups of rumen microbes in comparison with monensin (5 μM), one of the most commonly used ionophores in ruminant...

S TUDIES by Appleby et al. (1956), Gutierrez and tlungate (1957), Eadie et al. (1959) and Eadie and Hollson (1962) indicated that ciliate protozoa normally inhabiting the rumen exerted considerable influence upon end products of rumen fermentation and upon tureen bacterial populations. The full significance of protozoa to the nutrition of cattle and sheep is not clear. However, Christiansen et ...

The feed and feces of a continuously fed sheep were analyzed for carbon, hydrogen, and nitrogen, with oxygen as the remainder. The daily feed-feces weight difference was used as the reactant in an equation representing the rumen fermentation. The measured products were the daily production of volatile fatty acids (VFA), CH4, CO2, and ammonia. The carbon unaccounted for was assumed to be in the ...

A number of studies have been conducted to elucidate the properties and mechanism of the hydrogenation of Clg unsaturated fatty acids by rumen micro-organisms. Progress in this area has been reviewed by Dawson & Kemp (1970). During screening of a number of pure cultures of rumen bacteria, several species have been shown to hydrogenate linoleate to trans-octadecenoate (Polan, McNeill & Tove, 196...

I. Sheep, cows and calves fitted with rumen cannulas were given diets mostly containing 10-16 g nitrogen/kg dry matter and consisting of roughage and cereals. Mixed bacteria w-ere separated from samples of their lumen contents. 2. Bacteria taken 4-6 h after a feed from calves which were kept in an experimental calfhouse with no contact with adult animals (environment -4) contained more a-dextra...

Robert Hungate, considered the father of rumen microbiology, was the first to initiate a systematic exploration of the microbial ecosystem of the rumen, but he was not alone. The techniques he developed to isolate and identify cellulose-digesting bacteria from the rumen have had a major impact not only in delineating the complex ecosystem of the rumen but also in clinical microbiology and in th...

Studies on the quantitative significance of protozoa on carbon and nitrogen digestion and metabolism in the rumen were carried out in sheep given a diet of pelleted concentrate (500 g/d) and chopped hay (500 g/d). Measurements were made of apparent digestibility; flows of organic matter and dietary and microbial non-ammonia N (NAN) (using 15NH4+) to the duodenum; and rates of production, interc...