Rumen fluid

Vitamins such as thiamin, biotin, and vitamin Bj2 are often added. Once again, the requirements of anaerobes are somewhat greater, and a more extensive range of vitamins that includes pantothenate, folate, and nicotinate is generally employed. In some cases, additions of low concentrations of peptones, yeast extract, casamino acids or rumen fluid may be used, though in higher concentrations, metabolic ambiguities may be introduced since these compounds may serve as additional carbon sources. 

Beuvink JMW, Spoelstra SF, Hogendorp RJ. An automated method for measuring time-course of gas production of feedstuff incubated with buffered rumen fluid. Netherland Journal of Agricultural Science. 1992 40 401-407. 

Cone JW, Gelder AH, Visscher GJW, Oudshoom L. Influence of rumen fluid and substrate concentration on fermentation kinetics measured with fully automated time related gas production apparatus. Animal Feed Science and Technology. 1996 61 113-128. 

Action pattern A was observed with extracellular, endopectate lyase of Bacillus polymyxa,4,240 with extra- and intra-cellular lyase of Erwinia carotovora,241 with extracellular enzyme of Xanthomonas campestris,23S and with lyase produced by Bacteroides ruminicola242 isolated from the rumen fluid of sheep.243... 

Go lab, T., Herberg, R.J., Gramlich, J.V., Raun, A.P., and Probst, GW. Fate of benefin in soils, plants, artificial rumen fluid, and the mminant animal, 7 Agric. Food Chem., 18(5) 838-844,1970. 

Cook, J.W. 1957. In vitro destruction of some organophosphate pesticides by bovine rumen fluid. Agric. Food. Chem. 5 859-863. 

L.L., Lisak, J., Stolz, J.F., Oremland, R.S. (2002). Dissimila-tory arsenate reductase activity and arsenate-respiring bacteria in bovine rumen fluid, hamster feces, and the termite hindgut. FEMS Microbiol. Ecol. 41 59-67. 

In work with M thermolithotrophicus, using D2O and C-formate, the hydrogen in the methane molecule was shown to originate from the H in the medium, not via the H originally on formate [325], in contrast to direct reduction reported based on experiments with rumen fluid enrichments [326]. Work with purified FDH from M. formicicum agrees with the conclusion that the H in methane arises from the H in water [327]. 

The observation of Bauchop that small amounts of chloroform inhibit methane formation in rumen fluid (16), prompted us to examine the effect of chlorinated hydrocarbons on methane formation in bacterial extracts. Chloroform, carbon tetrachloride, and methylene chloride were found to be competitive inhibitors of methane formation (17),... 

In 1958 Smith and Hungate (17) described Methanobacterium rumi-nantium, which was present in large numbers in rumen content, and although detailed nutritional studies were not done, they showed that it required unknown growth factors which were present in rumen fluid but not found in many other nutritious materials such as yeast extract or peptones. In more recent studies, we confirmed and extended the nutritional information on M. ruminantium 23), and others have shown that other species require organic growth factors different from those required as energy source (16, 24). 

Figure J. Growth response of strain Ml, a rumen strain of Methanobacterium ruminantium, and strain PS, a sludge strain of M. ruminantium, to ammonia. The basal medium for strain Ml was the basal medium (Table II) plus 1.33 mM glycine, 0.95 mM i.-arginine, 1.34 mM la-methionine, 0.48 mM i.-histidine, and 1.68 mM la-threonine. The basal medium for strain PS was that indicated in Table II but with Dowex 50-treated rumen fluid and volatile acids other than acetate deleted. Ammonia was added as (NHi SOf, and other conditions were as indicated in...

Figure 3. Growth of strain PS in defined basal medium —Le., that indicated in Table II but with 3.8 mM (NHJ2S0 added and with rumen fluid and volatile acids other than acetate deleted...

Figure 4. Growth response of strain PS to sodium acetate in the defined basal medium—i.e., that indicated in Table II but with 3.8 mM (NH 1 )280added and with rumen fluid and volatile acids other than acetate deleted. NaCl (O) or Na2COg ( ) were added to maintain the normality of Na constant with the varying concentrations of acetate. Data indicate means of three tubes.

As with M. ruminantium, Methanobacterium strain MOH can utilize neither peptides nor amino acids as a nitrogen source replacing NH4 (Figures 5 and 7). NH4 utilization is essentially the same (Figure 8) when NH4 is the nitrogen source or when rumen fluid, amino acids, yeast extract, and Trypticase are present in the medium as complex sources of nitrogen that would be utilized in place of NH4 by most heterotrophic bacteria other than some rumen carbohydrate-fermenting anaerobes (11). 

MOH in media with as nitrogen source and with complex nitrogen sources added. Medium was the same as the basal shown in Figure 5 but with 12.2 mM sodium acetate and 2 mM (NH )2SO added or the same medium but with 20% of clarified rumen fluid, 0.5% of Trypticase, 0 2% of yeast extract and the mixture of i.-amino acids added (Figure 7). Ammonia fixed was determined as indicated in... 

The second most prevalent CLA isomer in ruminant fat is trans-1, cis-9 CLA, representing 3 16% of total CLA in ruminant fat (Corl et al., 2002 Parodi, 2003 Piperova et al., 2000, 2002 Shingfield et al., 2003 Yurawecz et al., 1998). A number of the studies previously described have determined the source of trans-1, cis-9 CLA in ruminant fat. Corl et al. (2002) showed that the trans-1, cis-9 CLA in milk fat was derived almost exclusively from endogenous synthesis by using both sterculic acid and trans-10, cis-12 CLA to inhibit A-9-desaturase they also found that trans-1, cis-9 CLA concentration in rumen fluid was very low and at the limit of detection. Similarly, Piperova et al. (2002) found that virtually all of the trans-1, cis-9 CLA in milk fat was produced post-ruminally. As mentioned previously, trans-1 18 1, a minor BH intermediate in ruminal contents, also is a substrate for A-9-desaturase (Mahfouz et al., 1980 Pollard et al., 1980). 

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