An in vitro assessment of amino acid requirements for optimal xylan fermentation by mixed ruminal micro-organisms from the sheep rumen

2003 ◽  
Vol 2003 ◽  
pp. 49-49
Author(s):  
A. Y. Guliye ◽  
C. Atasoglu ◽  
N. McKain ◽  
R. J. Wallace
Keyword(s):  
Amino Acids ◽  
Microbial Growth ◽  
Plant Polysaccharides ◽  
Plant Fibre ◽  
Amino Acid Requirements ◽  
In Vitro Assessment ◽  
Sheep Rumen ◽  
Main Components ◽  
Micro Organisms

Ruminal microbes play a important role in the fermentation of structural plant polysaccharides, and constitute a major source of protein for the animal. Dietary protein provides amino acids which generally stimulate microbial growth rates and yields. The aim of this experiment was to identify, using a deletion approach, which individual amino acids limit fermentation of one of the main components of plant fibre, xylan.

In vitro microbial growth as affected by the type of carbohydrate and the source of nitrogen

2001 ◽  
Vol 2001 ◽  
pp. 152-152
Author(s):  
M.L. Tejido ◽  
M.D. Carro ◽  
M. J. Ranilla ◽  
S. López
Keyword(s):  
Amino Acids ◽  
Microbial Growth ◽  
Rumen Bacteria ◽  
Optimum Growth ◽  
N Sources ◽  
N Form ◽  
Micro Organisms

The nitrogen (N) requirements for optimum growth of ruminal micro-organisms are still a matter of controversy. Whereas the results of some experiments indicate that peptides and amino acids stimulate the growth of mixed rumen bacteria in comparison to ammonia, no effect due to the N form has been found in other studies. Therefore, it has been suggested that growth of rumen micro-organisms would be stimulated only when the rate of provision of energy permitted (Cruz Soto et al., 1994). The aim of this study was to investigate the effect of two N sources (ammonia and isolated soyabean protein) on the in vitro fermentation of two substrates (starch and cellulose) differing in their rate of fermentation.

Assessment of amino acid requirements for optimum fermentation of xylan by mixed micro-organisms from the sheep rumen

2005 ◽  
Vol 80 (3) ◽  
pp. 353-360 ◽  
Author(s):  
A. Y. Guliye ◽  
C. Atasoglu ◽  
R. J. Wallace
Keyword(s):  
Amino Acids ◽  
Volatile Fatty Acid ◽  
Fatty Acid Production ◽  
Fermentation Rate ◽  
Ruminal Microorganisms ◽  
N Source ◽  
Amino Acid Requirements ◽  
Mixed Grass ◽  
Sheep Rumen ◽  
Micro Organisms

AbstractA deletion approach was undertaken to identify which amino acids (AA) most limited the growth of mixed ruminal microorganisms on xylan. Ruminal fluid was withdrawn from sheep receiving a mixed grass hay/concentrate diet and incubated for 24 h with oat spelts xylan in the presence or absence of a mixture of 20 AA or the same mixture with a single AA deleted. Gas and volatile fatty acid production were increased by the AA mixture in comparison with incubations in which ammonia was the only added nitrogen (N) source, and the deletion of each of the aromatic AA, tyrosine, phenylalanine and tryptophan, as well as leucine and methionine, led to decreases (P< 0·05) in fermentation rate. The addition of aromatic AA as a mixture to ammonia-only fermentations increased (P< 0·05) the fermentation rate but failed to replicate the benefits of the complete mixture of AA. Although the addition of all 20 AA increased (P< 0·05) the microbial yield by up to 0·56, no single AA deletion had a significant (P> 0·05) influence on microbial yield, and the aromatic AA mixture also did not increase the microbial yield on xylan over the yield with ammonia as sole N source. It was concluded that aromatic AA may be first-limiting for xylan fermentation, but they cannot replace the benefits of a complete mixture of 20 AA in stimulating xylan fermentation by ruminal micro-organisms.

Effect of nitrogen form on growth of rumen micro-organism in vitro

1998 ◽  
Vol 22 ◽  
pp. 309-311
Author(s):  
M. D. Carro ◽  
E. L. Miller
Keyword(s):  
Amino Acids ◽  
Culture System ◽  
Microbial Growth ◽  
Basal Diet ◽  
Nitrogen Form ◽  
Rumen Microbes ◽  
N Source ◽  
Micro Organisms

Rumen microbes utilize mainly ammonia as a nitrogen (N) source for their growth but some species also use a variety of amino acids (AA) or peptides. Several studies have shown both an enhanced fibre digestion and efficiency of rumen micro-organisms when N sources such as AA, peptides and protein were provided in addition to ammonia (Griswold et al.,1996). However, no difference either in digestion or in growth of rumen microbes was found in other in vivo(Fujimaki et al.,1989) and in vitro (Kernick, 1991) studies. The objective of this experiment was to investigate the effects of protein, peptides, AA and ammonia on microbial growth and fermentation of an all fibre basal diet in a semicontinuous culture system (RUSITEC; Czerkawski and Breckenridge, 1977).

scholarly journals In vitro assessment of the capacity of certain mycotoxin binders to adsorb some amino acids and water-soluble vitamins

2020 ◽  
Vol 103 (4) ◽  
pp. 3125-3132
Author(s):  
A. Kihal ◽  
M. Rodriguez-Prado ◽  
C. Godoy ◽  
C. Cristofol ◽  
S. Calsamiglia
Keyword(s):  
Amino Acids ◽  
Water Soluble ◽  
In Vitro Assessment

Repeatability of in vitro digestibility assays of forages when using fresh, frozen or freeze-dried cow faeces instead of sheep rumen liquor as sources of micro-organisms

1995 ◽  
Vol 1995 ◽  
pp. 110-110 ◽  
Author(s):  
S Akhter ◽  
E Owen ◽  
M K Theodorou ◽  
S L Tembo ◽  
E R Deaville
Keyword(s):  
Freeze Drying ◽  
Rumen Fluid ◽  
In Vitro Digestibility ◽  
Two Stage ◽  
Freeze Dried ◽  
Fresh Frozen ◽  
Sheep Rumen ◽  
Micro Organisms

Previous studies (El Shaer, Omed and Axford, 1987; Akhter, Owen, Fall, O'Donovan and Theodorou, 1994) with the two-stage in vitro procedure of Tilley and Terry (1963) have shown a high correlation between digestibilities of forages as determined using either sheep rumen liquor, sheep faeces or cow faeces as the microbial inoculum. In the first study of the of the present investigation one objective was to examine the repeatability of these digestibility measurements when made on different occasions. A second objective was to assess whether the correlations between faecal and rumen fluid based inocula could be improved if microorganisms were obtained from pairs rather than individual animals. The objective in the second study using forages of known in vivo digestibility, was to investigate the effect of freezing or freeze-drying of faeces on the repeatability of digestibilities of forages determined in vitro using micro-organisms from cow faeces.

scholarly journals Digestion of grass lipids and pigments in the sheep rumen

1974 ◽  
Vol 32 (2) ◽  
pp. 327-340 ◽  
Author(s):  
R. M. C. Dawson ◽  
Norma Hemington
Keyword(s):  
Small Proportion ◽  
Polar Compounds ◽  
The Other ◽  
Chlorophyll Pigments ◽  
Rapid Decomposition ◽  
Other Hand ◽  
Sheep Rumen ◽  
Micro Organisms

1. Digestion of grass lipids and pigments in the rumen of the sheep has been studied during starvation and following the administration of 14C-labelled grass.2. Both galactolipids contained in chloroplasts are rapidly degraded, although mono-galactosyldiglycerides disappear faster than digalactosyldiglycerides. It was concluded that rumen micro-organisms are mainly responsible for this degradation, although grass itself also contains enzymes which can degrade galactolipids.3. Rumen contents can degrade added 14C-labelled mono- and digalactosyldiglycerides in vitro at a rate sufficient to account for the disappearance of galactolipids in the intact rumen. The initial enzyme attack is probably a successive deacylation to give monogalactosylglycerol and digalactosylglycerol.4. Most of the chlorophyll pigments are rapidly converted into phaeophytins by loss of magnesium. A small proportion of chlorophyll a and more of chlorophyll b remains intact even after 24 h starvation. On the other hand, about half the phaeophytin undergoes further rapid decomposition to yield phylloerythrin.5. Although the grass phospholipids are extensively degraded, β-carotenes and many non-polar compounds, e.g. steroids, appear to undergo little change in the rumen.

In vitromicrobial growth and rumen fermentation of different substrates as affected by the addition of disodium malate

2005 ◽  
Vol 81 (1) ◽  
pp. 31-38 ◽  
Author(s):  
M. L. Tejido ◽  
M. J. Ranilla ◽  
R. García-Martínez ◽  
M. D. Carro
Keyword(s):  
Dry Matter ◽  
Microbial Growth ◽  
Rumen Fermentation ◽  
Gas Production ◽  
Mean Values ◽  
Batch Cultures ◽  
Production Values ◽  
Micro Organisms ◽  
Microbial N

AbstractThe effects of two concentrations of disodium malate on thein vitrofermentation of three substrates differing in their forage: concentrate ratio (0·8: 0·2, 0·5: 0·5 and 0·2: 0·8; g/g dry matter; low-, medium- and high-concentrate substrates, respectively) by rumen micro-organisms were studied using batch cultures. Rumen contents were collected from four Merino sheep offered lucerne hay ad libitum and supplemented daily with 400 g concentrate. Disodium malate was added to the incubation bottles to achieve final concentrations of 0, 4 and 8 mmol/l malate and15N was used as a microbial marker. Gas production was measured at regular intervals from 0 to 120 h of incubation to study fermentation kinetics. When gas production values were corrected for gas released from added malate, no effects (P> 0·05) of malate were detected for any of the estimated gas production parameters. In 17-h incubations, the final pH and total volatile fatty acid (VFA) production were increased (P< 0·001) by the addition of malate, but no changes (P> 0·05) were detected in the final amounts of ammonia-N and lactate. When net VFA productions were corrected for the amount of VFA produced from malate fermentation itself, adding malate did not affect (P> 0·05) the production of acetate, propionate and total VFA. Malate reduced methane (CH4) production by proportionately 0·058, 0·013 and 0·054 for the low-, medium- and high-concentrate substrates, respectively. Adding malate to batch cultures increased (P< 0·01) rumen microbial growth (mean values of 16·6, 18·3 and 18·4 mg of microbial N for malate at 0, 4 and 8 mmol/l, respectively), but did not affect (P> 0·05) its efficiency of growth (55·5, 56·7 and 54·3 mg of microbial N per g of organic matter apparently fermented for malate at 0, 4 and 8 mmol/l, respectively). There were no interactions (P> 0·05) malate × substrate for any of the measured variables, and no differences (P> 0·05) in pH, CH4production and microbial growth were found between malate at 4 and 8 mmol/l. The results indicate that malate had a beneficial effect on in vitro rumen fermentation of substrates by increasing VFA production and microbial growth, and that only subtle differences in the effects of malate were observed between substrates. Most of the observed effects, however, seem to be due to fermentation of malate itself.

scholarly journals A comparative study of ruminal activity in Churra and Merino sheep offered alfalfa hay

1997 ◽  
Vol 65 (1) ◽  
pp. 121-128 ◽  
Author(s):  
M. J. Ranilla ◽  
M. D. Carro ◽  
C. Valdés ◽  
F. J. Giráldez ◽  
S. López
Keyword(s):  
Cell Wall ◽  
Rumen Fluid ◽  
Merino Sheep ◽  
Rumen Ph ◽  
Sheep Rumen ◽  
Fermentation Parameters ◽  
Micro Organisms ◽  
Kinetics Of

AbstractA study was carried out to compare the fermentation parameters and kinetics of digestion of a range of different foods in the rumen of two breeds of sheep (Churra and Merino). Ten mature sheep (five Churra and five Merino), each fitted with a rumen cannula, were used in this study. In situ rumen degradability of both dry matter (DM) and cell wall was greater in Churra than in Merino sheep, the breed differences being significant for most of the foods used in the study (P < 0·05). These differences were greater when the foods had a higher cell wall concentration and this could be related to differences in the ruminal environment. However, when the foods were incubated with rumen fluid their in vitro organic matter (OM) degradability was similar in both breeds. Rumen pH was higher (P < 0·05) and ammonia concentrations were lower (P < 0·05) in Churra than in Merino sheep. Rumen volatile fatty acid concentrations tended to be higher in Merino than in Churra sheep, though differences were only significant just before feeding (P < 0·05). The ratio acetate: propionate was higher in the Churra than Merino breed before and 12 h after feeding (P < 0·05). Protozoa numbers in rumen liquid were similar for both genotypes. The greater degradation of forages in the rumen of Churra sheep is discussed in relation to the possible higher activity of fibre-degrading micro-organisms and the greater buffering capacity of the rumen contents against fermentation acids, which could result in more favourable conditions for the microbial degradation of foods in the rumen.

The Contribution of Caseins to the Amino Acid Supply for Lactococcus lactis Depends on the Type of Cell Envelope Proteinase

1998 ◽  
Vol 64 (6) ◽  
pp. 1991-1996 ◽  
Author(s):  
Benedicte Flambard ◽  
Sandra Helinck ◽  
Jean Richard ◽  
Vincent Juillard
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Amino Acid ◽  
Lactococcus Lactis ◽  
Cell Envelope ◽  
Essential Amino Acids ◽  
Genetically Engineered ◽  
Amino Acid Requirements ◽  
Rate Limiting

ABSTRACT The ability of caseins to fulfill the amino acid requirements ofLactococcus lactis for growth was studied as a function of the type of cell envelope proteinase (PI versus PIII type). Two genetically engineered strains of L. lactis that differed only in the type of proteinase were grown in chemically defined media containing αs1-, β-, and κ-caseins (alone or in combination) as the sources of amino acids. Casein utilization resulted in limitation of the growth rate, and the extent of this limitation depended on the type of casein and proteinase. Adding different mixtures of essential amino acids to the growth medium made it possible to identify the nature of the limitation. This procedure also made it possible to identify the amino acid deficiency which was growth rate limiting for L. lactis in milk (S. Helinck, J. Richard, and V. Juillard, Appl. Environ. Microbiol. 63:2124–2130, 1997) as a function of the type of proteinase. Our results were compared with results from previous in vitro experiments in which casein degradation by purified proteinases was examined. The results were in agreement only in the case of the PI-type proteinase. Therefore, our results bring into question the validity of the in vitro approach to identification of casein-derived peptides released by a PIII-type proteinase.

Effect of fibre source on the efficiency of microbial synthesis by mixed microorganisms from the sheep rumen in vitro

2001 ◽  
Vol 2001 ◽  
pp. 151-151 ◽  
Author(s):  
M. J. Ranilla ◽  
S. López ◽  
M. D. Carro ◽  
R. J. Wallace ◽  
C. J. Newbold
Keyword(s):  
Protein Synthesis ◽  
Physical Properties ◽  
Culture System ◽  
Gas Production ◽  
Microbial Protein ◽  
Microbial Synthesis ◽  
Microbial Protein Synthesis ◽  
Plant Fibre ◽  
Sheep Rumen

The efficiency and rate of microbial protein synthesis in the rumen depend on several factors, of which the chemical and physical properties of the plant fibre are among the most important. Estimation of microbial yield and fermentation rate can be obtained from in vitro experiments, which combine gas production and substrate degradability measurements and/or use microbial markers. The aim of this study was to investigate the effect of different fibre sources on microbial protein synthesis in a batch culture system in vitro.

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