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.

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).

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.

scholarly journals Hydrolysis of14C-labelled proteins by rumen micro-organisms and by proteolytic enzymes prepared from rumen bacteria

1983 ◽  
Vol 50 (2) ◽  
pp. 345-355 ◽  
Author(s):  
R. J. Wallace
Keyword(s):  
Proteolytic Enzymes ◽  
Rumen Fluid ◽  
Performic Acid ◽  
Cross Linking ◽  
Acid Oxidation ◽  
Rumen Bacteria ◽  
Rate Of Hydrolysis ◽  
Micro Organisms ◽  
Hydrolysis Of

1. Proteins were labelled with14C in a limited reductive methylation using [14C]formaldehyde and sodium borohydride.2. The rate of hydrolysis of purified proteins was little (< 10%) affected by methylation and the14C-labelled digestion products were not incorporated into microbial protein during a 5 h incubation with rumen fluid in vitro. It was therefore concluded that proteins labelled with14C in this way are valid substrates for study with rumen micro-organisms.3. The patterns of digestion of14C-labelled fish meal, linseed meal and groundnut-protein meal by rumen micro-organisms in vitro were similar to those found in vivo.4. The rates of hydrolysis of a number of14C-labelled proteins, including glycoprotein II and lectin from kidney beans (Phaseolus vulgaris), were determined with mixed rumen micro-organisms and with proteases extracted from rumen bacteria. Different soluble proteins were digested at quite different rates, with casein being most readily hydrolysed.5. Proteins modified by performic acid oxidation, by cross-linking using 1,6-di-iso-cyanatohexane or by diazotization were labelled with14C. Performic acid treatment generally increased the susceptibility of proteins to digestion, so that the rates of hydrolysis of performic acid-treated proteins were more comparable than those of the unmodified proteins. Cross-linking resulted in a decreased rate of hydrolysis except with the insoluble proteins, hide powder azure and elastin congo red. Diazotization had little effect on the rate of hydrolysis of lactoglobulin and albumin, but inhibited casein hydrolysis and stimulated the breakdown of γ-globulin.

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.

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).

scholarly journals Effect of supplementing a fibre basal diet with different nitrogen forms on ruminal fermentation and microbial growth in an in vitro semi-continuous culture system (RUSITEC)

1999 ◽  
Vol 82 (2) ◽  
pp. 149-157 ◽  
Author(s):  
M. D. Carro ◽  
E. L. Miller
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Microbial Growth ◽  
Volatile Fatty Acids ◽  
Basal Diet ◽  
Ruminal Fermentation ◽  
Acid Detergent Fibre ◽  
Preferential Uptake ◽  
Microbial N

Incubation trials were carried out with the rumen simulation technique (RUSITEC) to study the effects of four forms of N on the growth of ruminal micro-organisms and the fermentation variables when an all-fibre basal diet was incubated. The basal diet consisted of 10 g neutral-detergent fibre (NDF) from grass hay plus 2 g NDF from sugarbeet pulp. N forms were isolated soyabean protein, soyabean peptides, amino acids blended to profile soyabean protein and NH3 as NH4Cl. Half of the daily N supply was infused as NH4Cl and the other half was infused as each of the four treatments described. Non-NH3 N (NAN) forms increased NDF (P = 0·006), acid-detergent fibre (P = 0·003) and cellulose (P = 0·015) disappearance after 48 h incubation, CO2 (P < 0·001), CH4 (P = 0·002) and total volatile fatty acids production (P < 0·001), as well as the molar percentages of isobutyrate, isovalerate and valerate, which reflected the fermentation of amino acid C skeletons. NAN treatments also increased microbial N flow (P < 0·001) compared with NH3, with peptides and protein supporting more (P = 0·036) than amino acids. The proportion of microbial N derived from NH3 decreased successively (P < 0·05) with NH3 > amino acids > peptides > protein treatments, indicating preferential uptake of peptides without passage through the NH3 pool. Microbial efficiency (g microbial N/kg organic matter apparent disappearance) was greater (P = 0·002) for the NAN forms than for the NH3 treatment, with peptides and protein treatments supporting higher (P = 0·009) values than amino acid treatment. These results indicate that N forms other than NH3 are required for optimal fibre digestion and microbial growth.

Influence of peptides, amino acids and urea on microbial activity in the rumen of sheep receiving grass hay and on the growth of rumen bacteria in vitro

1994 ◽  
Vol 49 (1-2) ◽  
pp. 151-161 ◽  
Author(s):  
R.Cruz Soto ◽  
Samirah A. Muhammed ◽  
C.J. Newbold ◽  
C.S. Stewart ◽  
R.J. Wallace
Keyword(s):  
Amino Acids ◽  
Microbial Activity ◽  
Rumen Bacteria ◽  
Grass Hay

Disappearance of dry matter and neutral detergent fibre (NDF) of sunflower meal treated with sodium hydroxide or formaldehyde by isolated mixed rumen bacteria usingin vitroculture

2009 ◽  
Vol 2009 ◽  
pp. 183-183
Author(s):  
M Danesh Mesgaran ◽  
T Mohammadabidi ◽  
A Heravi Moussavi ◽  
M Nassiry
Keyword(s):  
Sodium Hydroxide ◽  
Dry Matter ◽  
Rumen Bacteria ◽  
Plant Cell Walls ◽  
Cellulolytic Bacteria ◽  
Sunflower Meal ◽  
Neutral Detergent Fibre ◽  
Micro Organisms ◽  
Ruminal Digestion

Cellulolytic bacteria, such asRuminococcus albus,R. flavefaciensandFibrobacter succinogenesare major micro-organisms responsible for ruminal digestion of plant cell walls ingested by the animal due to their numerical predominance and metabolic diversity (Chenget al., 1991). It has been proposed that sodium hydroxide might breakdown hemicelluloses, expose the cellulose to microbial attachment and improve digestibility (Chenet al., 2006). The objective of this experiment was to estimate the disappearance of dry matter (DM) and neutral detergent fibre (NDF) of sunflower meal (25 g fat/kg DM; SM) as untreated or treated with formaldehyde (3 g/kg DM) or sodium hydroxide (40 g/kg DM) usingin vitroculture with isolated mixed rumen bacteria.

scholarly journals Influence of peptides and amino acids on fermentation rate and de novo synthesis of amino acids by mixed micro-organisms from the sheep rumen

1999 ◽  
Vol 81 (4) ◽  
pp. 307-314 ◽  
Author(s):  
Cengiz Atasoglu ◽  
Carmen Valdés ◽  
C. James Newbold ◽  
R. John Wallace
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
De Novo ◽  
Rumen Fluid ◽  
Amino Acid Synthesis ◽  
Fermentation Rate ◽  
N Sources ◽  
Micro Organisms ◽  
Microbial N

The influence of different N sources on fermentation rate and de novo amino acid synthesis by rumen micro-organisms was investigated in vitro using rumen fluid taken from four sheep receiving a mixed diet comprising (g/kg DM): grass hay 500, barley 299·5, molasses 100, fish meal 91, minerals and vitamins 9·5. Pancreatic casein hydrolysate (P; comprising mainly peptides with some free amino acids; 10 g/l), free amino acids (AA; casein acid hydrolysate + added cysteine and tryptophan; 10 g/l), or a mixture of L-proline, glycine, L-valine and L-threonine (M; 0·83 g/l each) were added to diluted (1:3, v/v), strained rumen fluid along with 15NH4Cl (A; 1·33 g/l) and 6·7 g/l of a mixture of starch, cellobiose and xylose (1:1:1, by weight). P and AA, but not M, stimulated net gas production after 4 and 8 h incubation (P < 0·05) in comparison with A alone. P increased microbial-protein synthesis (P < 0·05) compared with the other treatments. All of the microbial-N formed after 10 h was synthesized de novo from 15NH3 in treatment A, and the addition of pre-formed amino acids decreased the proportion to 0·37, 0·55, and 0·86 for P, AA, and M respectively. De novo synthesis of amino acids (0·29, 0·42 and 0·69 respectively) was lower than cell-N. Enrichment of alanine, glutamate and aspartate was slightly higher than that of other amino acids, while enrichment in proline was much lower, such that 0·83–0·95 of all proline incorporated into particulate matter was derived from pre-formed proline. Glycine, methionine, lysine, valine and threonine tended to be less enriched than other amino acids. The form in which the amino acids were supplied, as P or AA, had little influence on the pattern of de novo synthesis. When the concentration of peptides was decreased, the proportion of microbial-N formed from NH3 increased, so that at an initial concentration of 1 g peptides/l, similar to the highest reported ruminal peptide concentrations, 0·68 of cell-N was formed from NH3. Decreasing the NH3 concentration at 1·0 g peptides/l caused proportionate decreases in the fraction of cell-N derived from NH3, from 0·81 at 0·53 g NH3-N/l to 0·40 at 0·19 g NH3-N/l. It was concluded that different individual amino acids are synthesized de novo to different extents by mixed rumen micro-organisms when pre-formed amino acids are present, and that the source of N used for synthesis of cell-N and amino acids depends on the respective concentrations of the different N sources available; however, supplementing only with amino acids whose synthesis is lowest when pre-formed amino acids are present does not stimulate fermentation or microbial growth.

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