Use of a deletion approach to assess the amino acid requirements for optimum fermentation by mixed micro-organisms from the sheep rumen

C Atasoglu, A Y Guliye, R J Wallace

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Amino acids stimulate the growth rate and growth yield of ruminal micro-organisms, but the basis of this stimulation, in terms of amino acids which most limit growth, has never been fully established. Here, for the first time, a deletion approach was investigated using in vitro incubations of mixed ruminal micro-organisms supplied with a mixture of xylose, starch and cellobiose as energy sources and ammonia plus a complete amino acids mixture or mixtures with a single amino acid omitted as nitrogen sources, enabling the evaluation of the impact on ruminal fermentation of the deletion of a single amino acid from a complete amino acids mixture. Significant effects (P<0.05) on total gas production were observed after 10 h of incubation when glutamate, glutamine, isoleucine, leucine, phenylalanine, serine, tryptophan or tyrosine were deleted from the amino acids mixture. The only significant effect of an amino acid deletion on volatile fatty acid production at 10 h was with serine (P<0.05), although the effect of omitting others, including arginine, isoleucine, leucine and phenylalanine, approached significance (P<0.01). The removal of leucine caused a 0.09 decrease in growth yield (P<0.05); no other deletion affected the yield significantly (P>0.05). Net gas production for each treatment was calculated by subtracting gas production in the absence of carbohydrates from gas production in their presence, thus eliminating gas production from amino acids from the values. At all times up to 10 h, the most significant effects on net gas production were found when serine, leucine, or the aromatic amino acids were omitted from the amino acids mixture. Thus, the deletion approach confirmed that no single amino acid limits ruminal fermentation more than any other, although a few, principally phenylalanine, leucine and serine, have a particularly significant role in the ruminal fermentation rate of soluble, rapidly degraded materials and/or microbial growth efficiency.

Original languageEnglish
Pages (from-to)147-153
Number of pages7
JournalAnimal Science
Volume76
Issue number1
Publication statusPublished - Feb 2003

Keywords

  • amino acids
  • micro-organisms
  • rumen
  • sheep
  • microbial protein-synthesis
  • volatile fatty-acids
  • cellulolytic bacteria
  • nitrogen-metabolism
  • continuous culture
  • purified diet
  • growth rates
  • urea
  • peptides
  • invitro

Cite this

Use of a deletion approach to assess the amino acid requirements for optimum fermentation by mixed micro-organisms from the sheep rumen. / Atasoglu, C ; Guliye, A Y ; Wallace, R J.

In: Animal Science, Vol. 76, No. 1, 02.2003, p. 147-153.

Research output: Contribution to journalArticle

@article{fa047bf5f64344eab7b6fd9b53498368,
title = "Use of a deletion approach to assess the amino acid requirements for optimum fermentation by mixed micro-organisms from the sheep rumen",
abstract = "Amino acids stimulate the growth rate and growth yield of ruminal micro-organisms, but the basis of this stimulation, in terms of amino acids which most limit growth, has never been fully established. Here, for the first time, a deletion approach was investigated using in vitro incubations of mixed ruminal micro-organisms supplied with a mixture of xylose, starch and cellobiose as energy sources and ammonia plus a complete amino acids mixture or mixtures with a single amino acid omitted as nitrogen sources, enabling the evaluation of the impact on ruminal fermentation of the deletion of a single amino acid from a complete amino acids mixture. Significant effects (P<0.05) on total gas production were observed after 10 h of incubation when glutamate, glutamine, isoleucine, leucine, phenylalanine, serine, tryptophan or tyrosine were deleted from the amino acids mixture. The only significant effect of an amino acid deletion on volatile fatty acid production at 10 h was with serine (P<0.05), although the effect of omitting others, including arginine, isoleucine, leucine and phenylalanine, approached significance (P<0.01). The removal of leucine caused a 0.09 decrease in growth yield (P<0.05); no other deletion affected the yield significantly (P>0.05). Net gas production for each treatment was calculated by subtracting gas production in the absence of carbohydrates from gas production in their presence, thus eliminating gas production from amino acids from the values. At all times up to 10 h, the most significant effects on net gas production were found when serine, leucine, or the aromatic amino acids were omitted from the amino acids mixture. Thus, the deletion approach confirmed that no single amino acid limits ruminal fermentation more than any other, although a few, principally phenylalanine, leucine and serine, have a particularly significant role in the ruminal fermentation rate of soluble, rapidly degraded materials and/or microbial growth efficiency.",
keywords = "amino acids, micro-organisms, rumen, sheep, microbial protein-synthesis, volatile fatty-acids, cellulolytic bacteria, nitrogen-metabolism, continuous culture, purified diet, growth rates, urea, peptides, invitro",
author = "C Atasoglu and Guliye, {A Y} and Wallace, {R J}",
note = "Spares in Box VI.",
year = "2003",
month = "2",
language = "English",
volume = "76",
pages = "147--153",
journal = "Animal Science",
issn = "1357-7298",
publisher = "British Society of Animal Science",
number = "1",

}

TY - JOUR

T1 - Use of a deletion approach to assess the amino acid requirements for optimum fermentation by mixed micro-organisms from the sheep rumen

AU - Atasoglu, C

AU - Guliye, A Y

AU - Wallace, R J

N1 - Spares in Box VI.

PY - 2003/2

Y1 - 2003/2

N2 - Amino acids stimulate the growth rate and growth yield of ruminal micro-organisms, but the basis of this stimulation, in terms of amino acids which most limit growth, has never been fully established. Here, for the first time, a deletion approach was investigated using in vitro incubations of mixed ruminal micro-organisms supplied with a mixture of xylose, starch and cellobiose as energy sources and ammonia plus a complete amino acids mixture or mixtures with a single amino acid omitted as nitrogen sources, enabling the evaluation of the impact on ruminal fermentation of the deletion of a single amino acid from a complete amino acids mixture. Significant effects (P<0.05) on total gas production were observed after 10 h of incubation when glutamate, glutamine, isoleucine, leucine, phenylalanine, serine, tryptophan or tyrosine were deleted from the amino acids mixture. The only significant effect of an amino acid deletion on volatile fatty acid production at 10 h was with serine (P<0.05), although the effect of omitting others, including arginine, isoleucine, leucine and phenylalanine, approached significance (P<0.01). The removal of leucine caused a 0.09 decrease in growth yield (P<0.05); no other deletion affected the yield significantly (P>0.05). Net gas production for each treatment was calculated by subtracting gas production in the absence of carbohydrates from gas production in their presence, thus eliminating gas production from amino acids from the values. At all times up to 10 h, the most significant effects on net gas production were found when serine, leucine, or the aromatic amino acids were omitted from the amino acids mixture. Thus, the deletion approach confirmed that no single amino acid limits ruminal fermentation more than any other, although a few, principally phenylalanine, leucine and serine, have a particularly significant role in the ruminal fermentation rate of soluble, rapidly degraded materials and/or microbial growth efficiency.

AB - Amino acids stimulate the growth rate and growth yield of ruminal micro-organisms, but the basis of this stimulation, in terms of amino acids which most limit growth, has never been fully established. Here, for the first time, a deletion approach was investigated using in vitro incubations of mixed ruminal micro-organisms supplied with a mixture of xylose, starch and cellobiose as energy sources and ammonia plus a complete amino acids mixture or mixtures with a single amino acid omitted as nitrogen sources, enabling the evaluation of the impact on ruminal fermentation of the deletion of a single amino acid from a complete amino acids mixture. Significant effects (P<0.05) on total gas production were observed after 10 h of incubation when glutamate, glutamine, isoleucine, leucine, phenylalanine, serine, tryptophan or tyrosine were deleted from the amino acids mixture. The only significant effect of an amino acid deletion on volatile fatty acid production at 10 h was with serine (P<0.05), although the effect of omitting others, including arginine, isoleucine, leucine and phenylalanine, approached significance (P<0.01). The removal of leucine caused a 0.09 decrease in growth yield (P<0.05); no other deletion affected the yield significantly (P>0.05). Net gas production for each treatment was calculated by subtracting gas production in the absence of carbohydrates from gas production in their presence, thus eliminating gas production from amino acids from the values. At all times up to 10 h, the most significant effects on net gas production were found when serine, leucine, or the aromatic amino acids were omitted from the amino acids mixture. Thus, the deletion approach confirmed that no single amino acid limits ruminal fermentation more than any other, although a few, principally phenylalanine, leucine and serine, have a particularly significant role in the ruminal fermentation rate of soluble, rapidly degraded materials and/or microbial growth efficiency.

KW - amino acids

KW - micro-organisms

KW - rumen

KW - sheep

KW - microbial protein-synthesis

KW - volatile fatty-acids

KW - cellulolytic bacteria

KW - nitrogen-metabolism

KW - continuous culture

KW - purified diet

KW - growth rates

KW - urea

KW - peptides

KW - invitro

M3 - Article

VL - 76

SP - 147

EP - 153

JO - Animal Science

JF - Animal Science

SN - 1357-7298

IS - 1

ER -