Synthesis of Amino Acids in the Rumen

Loosli, J. K.; Williams, Harold H.; Thomas, W. E.; Ferris, Fent H.; Maynard, L. A.

doi:10.1126/science.110.2849.144

Cited by 124 publications

(30 citation statements)

References 6 publications

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“…This is due to the presence of large numbers of microorganisms in the rumen which can synthesize enough of the essential amino acids to meet the needs of the animal (Loosli et al 1949). There nevertheless remains the possibility that the tissue metabolism of ruminants differs from that of monogastric animals.…”

Section: Introductionmentioning

confidence: 99%

On the Amino Acids Essential for the Tissues of the Sheep

Downes¹

1961

Aust. Jnl. Of Bio. Sci.

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SummaryA lactating ewe was injected intravenously with sodium [l. 14C]acetate and samples of the wool and milk produced subsequently were collected. Some of the casein from the milk produced 1-3 hr after the injection was hydrolysed and the distribution of 14C among most of the amino acids determined. The results showed that only the following amino acids became labelled: glutamic acid, aspartic acid, proline, alanine, arginine, and serine. By analogy with earlier work on cows by Black et al. (1957) it was concluded that these amino acids are also non· essential for the tissues of the sheep.The casein isolated from the milk produced during the first few hours had a much higher specific activity than the maximum observed in the wool. However, the results were consistent with the hypothesis that neither the wool keratin nor the casein were formed from the plasma proteins.

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Section: Introductionmentioning

confidence: 99%

On the Amino Acids Essential for the Tissues of the Sheep

Downes¹

1961

Aust. Jnl. Of Bio. Sci.

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“…Following reports by Loosli et al (1949) that ruminants are able to utilize non-protein nitrogen (NPN) sources to produce essential amino acids, Colbey & Mesler (1958) patented the use of melamine as an NPN source for ruminants. By recognizing the high nitrogen content of melamine and its structural similarities to cyanuric acid, which, according to Clark et al (1965), proved to be a safe NPN source for sheep, MacKenzie (1966) investigated the potential use of melamine as an NPN source for ruminants.…”

Section: Introductionmentioning

confidence: 99%

<i>In Vitro</i> Degradation of Melamine by Ruminal Microorganisms

Cruywagen¹,

Calitz²

2015

SA J. An. Sci.

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An in vitro study was conducted to determine the extent of melamine degradation in rumen liquor. Rumen liquor was collected from two ruminally cannulated Holstein cows on four separate dates, one week apart. Erlenmeyer flasks (250 mL) were prepared for incubation by adding 1000 mg of a dairy feed substrate, 100 mg melamine and 100 mL incubation medium, purged with CO 2 and fitted with rubber stoppers equipped with one-way gas release valves. The initial melamine concentration was thus 1000 mg/L. The substrates consisted of 600 mg of a commercial dairy concentrate, 200 mg lucerne hay and 200 mg oat hay. The incubation medium consisted of 19 mL rumen liquor, 77 mL of Van Soest buffer and 4 mL of a reducing solution. The flasks were incubated at 39 ºC for 0, 6, 24 or 48 hours (two flasks per time in each of four replicates). The 0 h incubation served as a control treatment to enable the calculation of melamine recovery values. For the control treatment (0 h), fermentation was terminated at the onset of the trial by aerating the rumen liquor and submerging the flasks in 50 mm ice. On termination of the incubation, 100 mL 0.2 M perchloric acid was added to each flask in order to dissolve any undegraded melamine. Melamine concentrations were determined by liquid chromatography-tandem mass spectrometry. Melamine degradation was low after 6 hours and 24 hours of incubation (3.2% and 5.5%, respectively) and increased to 13.6% after 48 h of incubation. It was concluded that melamine has low degradability in rumen liquor.

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“…Initial work carried out by Loosli et al (1949 ) indicated net synthesis of all amino acids by rumen microorganisms. Piana and Piva (1968) …”

Section: Introductionmentioning

confidence: 99%

Tryptophan Synthesis From Serine by Rumen Microorganisms in Vitro

Candlish¹,

Devlin²,

LaCroix³

1972

Can. J. Anim. Sci.

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Biosynthesis of tryptophan by rumen micro-tion of label in the tryptophan area of the organisms was investigated using the con-thin-layer chromatograms following column tinuous-flow artificial rumen apparatus. L-chromatography of saline and rumen liquor. Serine-"C (U) was incubated with rumen Although labelled serine was utilized in synmicroorganisms. Most of the serine was thesis of tryptophan, the proportion of tryptorapidly metabolized to volatile fatty acids. The phan containing label was about 0.0001%. synthesis of tryptophan was indicated by detec-RESUME On a 6tudi6, au moyen d'un rumen artificiel )r tion du marqueur radioactif dans la bande du courant continu, la biosynthEse du trypto-tryptophane des chromatogrammes sur couche phane par la microflore du rumen. A cet effet, mince obtenus aprbs chromatographie sur on a fait incuber de la r,-s6rine, marqu6e au colonne de la solution saline et de la liqueur '1C, avec les microorganismes du iumen. de rumen. MOme si la s6rine marqu6e a servi Presque toute la s6rine s'est rapidement m6ta-i Ia synthdse du tryptophane, seulement bolis6e en acides gras volatiles. La synthdse 0.0001% du tryptophane contenait du "C. du tryptophane a 6t6 constat6e par la d6tec-

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Synthesis of Amino Acids in the Rumen

Cited by 124 publications

References 6 publications

On the Amino Acids Essential for the Tissues of the Sheep

On the Amino Acids Essential for the Tissues of the Sheep

<i>In Vitro</i> Degradation of Melamine by Ruminal Microorganisms

Tryptophan Synthesis From Serine by Rumen Microorganisms in Vitro

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