Integration of in vitro parameters by mechanistic modelling to predict recycling of microbial nitrogen in the rumen

1998 ◽  
Vol 22 ◽  
pp. 158-160
Author(s):  
J. Dijkstra ◽  
J. France ◽  
S. Tamminga
Keyword(s):  
Bacterial Protein ◽  
Protein Breakdown ◽  
Microbial Protein ◽  
Evaluation Systems ◽  
Microbial Nitrogen ◽  
Substrate Conversion ◽  
Micro Organisms ◽  
Protein Supply

In protein evaluation systems for ruminants, the microbial protein supply is calculated from the amounts of rumen degradable organic matter and nitrogen (N) using empirical equations. A variable part of the rumen synthesized microbial protein does not reach the duodenum but is recycled within the rumen (review Firkins, 1996). Since energy is required for its re-synthesis and degraded microbial protein is subject to deamination, the efficiency of substrate conversion into microbial protein in the rumen is affected by microbial recycling. Rumen protozoa have a major impact upon this recycling through engulfment of micro-organisms and autolysis. In vitro, bacterial protein breakdown is proportionately reduced by some 0·9 upon removal of protozoa (Wallace and McPherson, 1987). Defaunation of the rumen increases the efficiency of microbial protein synthesis in vivo significantly (review Jouany et al., 1988).

Cloning and properties of a lysozyme from the rumen ciliate protozoan, Entodinium caudatum

2000 ◽  
Vol 2000 ◽  
pp. 55-55
Author(s):  
S. C. P. Eschenlauer ◽  
N. R. McEwan ◽  
R. Onodera ◽  
R. J. Wallace ◽  
C. J. Newbold
Keyword(s):  
Small Intestine ◽  
Rumen Bacteria ◽  
Bacterial Protein ◽  
Protein Breakdown ◽  
Microbial Protein ◽  
Ciliate Protozoan ◽  
Micro Organisms ◽  
Rumen Protozoan ◽  
Ciliate Protozoa

The breakdown of bacterial protein in the rumen leads to a nutritionally wasteful cycle of protein breakdown and re-synthesis, decreasing the flow of microbial protein from the rumen to the small intestine (Williams and Coleman, 1992). Engulfment and subsequent digestion by ciliate protozoa was demonstrated to be the most important cause of bacterial lysis in mixed ruminal micro-organisms incubated in vitro (Wallace and McPherson, 1987). Despite their importance, little is known about the enzymes responsible for the digestion of bacteria in rumen ciliates. The objective of this study was to clone and characterise a lysozyme from Entodinium caudatum, a common rumen protozoan important in the ingestion and breakdown of rumen bacteria (Williams and Coleman, 1992).

Microbial protein kinetics for sheep fed with three different hays using15N as marker

2003 ◽  
Vol 2003 ◽  
pp. 160-160
Author(s):  
I. C. S. Bueno ◽  
S. L. S. Cabral Filho ◽  
C. Longo ◽  
A. L. Abdalla
Keyword(s):  
Protein Synthesis ◽  
Protein Level ◽  
Microbial Fermentation ◽  
Microbial Protein ◽  
Protein Kinetics ◽  
Evaluation Systems ◽  
Rumen Degradation ◽  
Protein Supply

Non-degradable dietetic protein supply depends on rumen degradation. Determination of microbial protein synthesized in the rumen as the result of microbial fermentation is important because microbial protein synthesis could be influenced by diet (Dove and Milne, 1994). Several evaluation systems consider the contribution of microbial protein on protein intestinal flow as a constant, based on feed intake. But this approach has presented great variations. The purpose of this work was to determinein vivomicrobial protein kinetics for sheep fed with three protein level hays.

CYTOSINE AS A MARKER FOR MICROBIAL NITROGEN LEAVING THE RUMEN

1984 ◽  
Vol 64 (5) ◽  
pp. 52-53 ◽  
Author(s):  
GERALD T. SCHELLING ◽  
FLOYD M. BYERS
Keyword(s):  
Sample Preparation ◽  
Good Accuracy ◽  
In Vivo Studies ◽  
Microbial Protein ◽  
Minimal Sample ◽  
Microbial Nitrogen ◽  
Pyrimidine Bases ◽  
Nitrogen Ratio

In vitro and in vivo studies were conducted to investigate the use of purine or pyrimidine bases as markers for rumen microbial nitrogen. The cytosine to microbial nitrogen ratio is a valid technique that has good accuracy and the advantage of minimal sample preparation. Key words: Rumen microbial protein, cytosine microbial marker

Effect of microbial isolates on microbial yield estimation in RUSITEC system

1998 ◽  
Vol 22 ◽  
pp. 306-308
Author(s):  
M. D. Carro ◽  
E. L. Miller
Keyword(s):  
Protein Synthesis ◽  
Liquid Phase ◽  
Solid Phase ◽  
Liquid Fraction ◽  
Microbial Protein ◽  
Microbial Protein Synthesis ◽  
Continuous Culture System ◽  
The One

The estimation of rumen microbial protein synthesis is one of the main points in the nitrogen (N)-rationing systems for ruminants, as microbial protein provides proportionately 0.4 to 0.9 of amino acids entering the small intestine in ruminants receiving conventional diets (Russell et al., 1992). Methods of estimating microbial protein synthesis rely on marker techniques in which a particular microbial constituent is related to the microbial N content. Marker : N values have generally been established in mixed bacteria isolated from the liquid fraction of rumen digesta and it has been assumed that the same relationship holds in the total population leaving the rumen (Merry and McAllan, 1983). However, several studies have demonstrated differences in composition between solid-associated (SAB) and fluid-associated bacteria in vivo (Legay-Carmier and Bauchart, 1989) and in vitro (Molina Alcaide et al, 1996), as well in marker : N values (Pérez et al., 1996). This problem could be more pronounced in the in vitro semi-continuous culture system RUSITEC, in which there are three well defined components (a free liquid phase, a liquid phase associated with the solid phase and a solid phase), each one having associated microbial populations.The objective of this experiment was to investigate the effect of using different bacterial isolates (BI) on the estimation of microbial production of four different diets in RUSITEC (Czerkawski and Breckenridge, 1977), using (15NH4)2 SO4 as microbial marker, and to assess what effects any differences would have on the comparison of microbial protein synthesis between diets.This study was conducted in conjunction with an in vitro experiment described by Carro and Miller (1997). Two 14-day incubation trials were carried out with the rumen simulation technique RUSITEC (Czerkawski and Breckenridge, 1977). The general incubation procedure was the one described by Czerkawski and Breckenridge (1977) and more details about the procedures of this experiment are given elsewhere (Carro and Miller, 1997).

The effect of nitrogen source on the in vitro cellulose digestion of chemically treated oat straw and poplar wood

1974 ◽  
Vol 82 (3) ◽  
pp. 571-573 ◽  
Author(s):  
I. O. A. Adeleye ◽  
W. D. Kitts
Keyword(s):  
Ammonium Hydroxide ◽  
Nitrogen Sources ◽  
Energy Fraction ◽  
Digestible Energy ◽  
Dietary Nitrogen ◽  
Microbial Nitrogen ◽  
Appropriate Treatment ◽  
Gross Energy ◽  
Micro Organisms

The gross energy of forages can be classified into three fractions, namely the unavailable fraction, the digestible energy fraction and the potentially digestible energy (PDE) fraction. The PDE fraction can only be made available by appropriate treatment and supplementation (Pigden & Heaney, 1969). In young forages the PDE fraction is relatively insignificant, but as the plant matures, the PDE fraction increases very rapidly. By treating matured forages with delignifying agents, increased nutrient digestibilities have been demonstrated Chandra & Jackson, 1971; Wilson & Pigden, 1964), but no significant improvement on the voluntary intake was achieved unless the treated material was supplemented with a source of nitrogen (Donefer, Adeleye & Jones, 1969). While Zafren (1960) used ammonium hydroxide (NH40H) as the treatment alkali, with the claim that the ammonium acetate resulting from the neutralization of the excess alkali could serve as an extra source of nitrogen in the treated straw, other investigators (Donefer et al. 1969) have adopted the method of supplementing the treated straw with a source of nitrogen. Since the efficiency with which dietary nitrogen is converted to microbial nitrogen in the rumen has a considerable influence on the efficiency the animal as a whole, studies herein reported were carried out to test the effectiveness with which rumen micro-organisms utilize different nitrogen sources in degrading cellulose in vitro.

The use of cytosine as a marker to estimate microbial protein synthesis in the rumen

1991 ◽  
Vol 1991 ◽  
pp. 107-107
Author(s):  
L.A. Sinclair ◽  
P.C. Garnsworthy ◽  
P.J. Buttery
Keyword(s):  
Protein Synthesis ◽  
Spectrophotometric Analysis ◽  
Diaminopimelic Acid ◽  
Nitrogen Flow ◽  
Microbial Protein ◽  
Hplc Separation ◽  
Microbial Nitrogen ◽  
Purine Content ◽  
Present Trial

Recently methods based upon the HPLC separation and detection of cytosine (Koenig 1980) and the spectrophotometric analysis of the total purine content of microbes (Zinn and Owens 1986) have been proposed to estimate microbial nitrogen flow at the duodenum. Little work has been undertaken in-vivo to evaluate cytosine as a marker and to compare it with current techniques. The present trial was designed to evaluate this marker and to compare it with diaminopimelic acid (DAPA), [3H]leucine and the total purine technique. In addition, recent reports (Hvelpund and Madsen 1985) have indicated that expressing miaobial efficiency in terms of carbohdrate, as opposed to organic matter degraded in the rumen, reduced the variation in microbial yield. This was also investigated.

Anaerobes in ejaculates of subfertile men

1995 ◽  
Vol 1 (5) ◽  
pp. 462-478 ◽  
Author(s):  
Waltraud Eggert-Kruse ◽  
Gerhard Rohr ◽  
Wolfram Ströck ◽  
Susanne Pohl ◽  
Beate Schwalbach ◽  
...  
Keyword(s):  
Tract Infection ◽  
Genital Tract ◽  
Anaerobic Bacteria ◽  
Cervical Mucus ◽  
Anaerobic Growth ◽  
Pathogenic Species ◽  
Genital Tract Infection ◽  
Micro Organisms

Abstract The clinical significance of micro-organisms in semen samples of asymptomatic subfertile patients is a matter of constant debate. Usually little attention is paid to anaerobic bacteria as they are sensitive to transportation and culturing, and differentiation is difficult, costly and time-consuming. In the present study, special screening was carried out for anaerobes in ejaculates in addition to the routine microbial cultures of genital secretions of both partners. In addition to standard semen analysis and evaluation of sperm ability to penetrate cervical mucus (CM) in vivo (postcoital testing) and in vitro using a standardized test system, semen samples from 126 randomly chosen males of couples with a median duration of infertility of 4 years were examined for colonization with anaerobic bacteria. All couples were without clinical signs or symptoms of genital tract infection. The special care taken for anaerobic growth in semen samples gave a high rate of positive cultures and showed that nearly all ejaculates (99%) were colonized with anaerobic micro-organisms, and potentially pathogenic species were found in 71% of men. This rate was more than four times higher than that obtained with routine cultures and standard transportation (16%). Anaerobic bacterial growth of ≥106 colony forming units (CFU)/ml was seen in 42% (total range 103-108 CFU/ml). In addition, aerobic growth was found in 96%(≥106 CFU/ml in 21%), potentially pathogenic species in 61% of semen specimens. There were no marked differences in the prevalence of anaerobic micro-organisms in patients with reduced or normal sperm count, motility or morphology. Nor was there any significant difference in anaerobic colonization between samples with impaired or good ability to penetrate CM of female partners (in vivo or in vitro), or the CM of fertile donors in the in-vitro sperm-cervical mucus penetration test (SCMPT) in this asymptomatic group of patients. There was no clear association between microbial colonization and subsequent fertility in vivo within an observation period of 6 months. The results of this study suggest that anaerobic bacteria are often not detected when routine methods for microbial evaluation are used. This should be considered during assisted reproduction and in patients with symptoms of genital tract infection and should lead to further studies in infertile patients where subclinical infection or inflammation is indicated by specific markers in semen samples.

Effect of defaunation on utilisation of poor quality tropical feed by sheep

1999 ◽  
Vol 1999 ◽  
pp. 113-113
Author(s):  
B. Teferedegne ◽  
P. O. Osuji ◽  
A. Odenyo ◽  
R. J. Wallace ◽  
C. J. Newbold
Keyword(s):  
Active Role ◽  
Poor Quality ◽  
Bacterial Protein ◽  
Microbial Protein ◽  
Proper Functioning ◽  
Protein Supply ◽  
Ciliate Protozoa

There are conflicting reports in the literature about the benefits of defaunation, the removal of ciliate protozoa from the rumen, in ruminant production. Ciliate protozoa are not essential for proper functioning of the rumen nor for the life of the host and that their contribution to microbial protein flowing to the lower gut is small (Williams and Coleman, 1992). Protozoa ingest and digest bacteria in the rumen decreasing the flow of microbial protein from the rumen, and inserting an energy wasting step in the net synthesis of bacterial protein in the rumen (Williams and Coleman, 1992). However, protozoa also play an active role in ruminal fibre digestion and up to 50% of ruminal carboxymethylcellulase activity is associated with the protozoal fraction (Williams and Colemans, 1992). Thus the effect of defaunation on animal productivity will be a balance between the increase in the supply of microbial protein leaving the rumen and any decrease in ruminal fibre digestion. The aim of this work was to determine the effect of defaunation on microbial protein supply and fibre digestion in sheep fed a poor quality tropical diet.

scholarly journals Increased activity of indoleamine 2,3-dioxygenase in serum from acutely infected dengue patients linked to gamma interferon antiviral function

2009 ◽  
Vol 90 (4) ◽  
pp. 810-817 ◽  
Author(s):  
Aniuska Becerra ◽  
Rajas V. Warke ◽  
Kris Xhaja ◽  
Barbara Evans ◽  
James Evans ◽  
...  
Keyword(s):  
Antiviral Effect ◽  
Denv Infection ◽  
Gamma Interferon ◽  
Indoleamine 2,3 Dioxygenase ◽  
Inhibition Of Growth ◽  
Healthy Donors ◽  
Antiviral Function ◽  
Micro Organisms

The depletion of l-tryptophan (L-Trp) has been associated with the inhibition of growth of micro-organisms and also has profound effects on T cell proliferation and immune tolerance. The enzyme indoleamine 2,3-dioxygenase (IDO) catalyses the rate-limiting step in the catabolic pathway of L-Trp. Gene expression analysis has shown upregulation of genes involved in L-Trp catabolism in in vitro models of dengue virus (DENV) infection. To understand the role of IDO during DENV infection, we measured IDO activity in sera from control and DENV-infected patients. We found increased IDO activity, lower levels of L-Trp and higher levels of l-kynurenine in sera from DENV-infected patients during the febrile days of the disease compared with patients with other febrile illnesses and healthy donors. Furthermore, we confirmed upregulation of IDO mRNA expression in response to DENV infection in vitro, using a dendritic cell (DC) model of DENV infection. We found that the antiviral effect of gamma interferon (IFN-γ) in DENV-infected DCs in vitro was partially dependent on IDO activity. Our results demonstrate that IDO plays an important role in the antiviral effect of IFN-γ against DENV infection in vitro and suggest that it has a role in the immune response to DENV infections in vivo.

scholarly journals PSI-27 Excretion of purine derivatives and rumen microbial protein synthesis in Nelore steers supplemented with low-moisture, sugarcane molasses-based block and fed low-quality forage

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 249-250
Author(s):  
Andresa L Feliciano ◽  
Sérgio A G Pereira-Junior ◽  
Yury Granja-Salcedo ◽  
Livia Maria Sampaio Ferraz Sepini de Souza Grilo ◽  
Luís Felipe Arelaro Artioli ◽  
...  
Keyword(s):  
Random Effect ◽  
Latin Square ◽  
Experimental Period ◽  
Sugarcane Molasses ◽  
Microbial Protein ◽  
Purine Derivatives ◽  
Microbial Nitrogen ◽  
Protein Supply ◽  
Protein Block ◽  
Corn Grain

Abstract The objective of this study was to determine the effects of supplementation of low-moisture, sugarcane molasses-based block (LMB) on steers fed low quality forage in the excretion of purine derivatives and in the synthesis of ruminal microbial protein. Six rumen cannulated Nellore steers steers (23 months, 350 ± 10 kg) were distributed in a 3 × 3 double Latin square design. The treatments were composed of Brachiaria brizantha ‘Marandu’ hay ad libtum as an exclusive source of bulky (93.65% DM, 3.97% CP and 81.76% NDF) and supplements: complete mineral blend with urea [UR, (urea, salt, mineral-vitamin premix)], a commercial protein supplement [PS, (corn grain, soybean meal, urea, salt and mineral-vitamin premix)] or low-moisture, cooked sugarcane molasses-based protein block [LMB, (cane molasses, cottonseed meal, soybean oil, urea, salt and mineral-vitamin premix)]. Each experimental period lasted 21 days (14 days of adaptation and 7 days of data collection). The total urinary volume was measured for five days in each experimental period. The urine was collected in rubber funnels fixed by elastic loops on the backs of the animals. The urine was conduct through hoses connected to a 20 L polyethylene bucket containing 250 mL of 20% H2SO4 solution. Every 24 hours, the collected urine was homogenized and the total excreted volume was measured. The data were analyzed using Software R, having as fixed effect the treatments and as animal random effect, period, Latin square and error. Supplementation with LMB lead to greater excretion of allantoin (P = 0.046), microbial nitrogen flow (P = 0.023) and higher microbial crude protein (P = 0.023) into the intestine compared to UR and PS. While no effect was observed on total purines and purines absorbed (P > 0.05). Thus, LMB supplementation for rumen cannulated Nellore steers fed low quality forage was effective to improve metabolizable protein supply.

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