Effects of the ionophore tetronasin on nitrogen metabolism by ruminal microorganisms in vitro

C J Newbold, R J Wallace, N McKain

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

The effects of tetronasin on ruminal protein metabolism were investigated in vitro using ruminal fluid from cattle receiving tetronasin in the diet, ovine ruminal fluid from animals not receiving tetronasin and pure cultures of proteolytic ruminal bacteria. Ruminal fluid from cattle receiving tetronasin in a predominantly barley diet had lower proteolytic (76% of control, P less than .10) and deaminative (58% of control, P less than .05) activities than controls after 42 d. The effect of deamination disappeared after 84 d, although the proteolytic activity remained lower (P less than .10) than that of controls. When tetronasin was added in vitro to ruminal fluid from sheep not receiving the ionophore, proteolytic activity (14C-labeled casein hydrolysis) was unaffected, but the rate of ammonia production from amino acids was decreased by 87% (P less than .01). Oligopeptide breakdown was inhibited to a lesser extent (21%, P less than .05). Dipeptidase activity (dialanine hydrolysis) was not affected. The addition of tetronasin to cultures of the ruminal bacteria Ruminobacter amylophilus and Bacteroides ruminicola had no influence on their protease, deaminase or dipeptidase activities. However, when the bacteria were adapted to grow in the presence of tetronasin, deamination of amino acids was severely inhibited (87 to 100%, P less than .01), even when tetronasin was absent from the incubation mixture. Tetronasin had no effect on the proteolytic activity of adapted cultures.(ABSTRACT TRUNCATED AT 250 WORDS)

Original languageEnglish
Pages (from-to)1103-9
Number of pages7
JournalJournal of Animal Science
Volume68
Issue number4
Publication statusPrint publication - Apr 1990
Externally publishedYes

Fingerprint

rumen microorganisms
Ionophores
ionophores
nitrogen metabolism
rumen fluids
Nitrogen
dipeptidases
deamination
rumen bacteria
Ruminobacter amylophilus
Prevotella ruminicola
hydrolysis
sheep
oligopeptides
amino acids
cattle
Deamination
protein metabolism
diet
Bacteria

Keywords

  • Amino Acids/metabolism
  • Animals
  • Anti-Bacterial Agents/pharmacology
  • Bacteria/drug effects
  • Caseins/metabolism
  • Cattle/metabolism
  • Dietary Proteins/metabolism
  • Furans/pharmacology
  • Ionophores/pharmacology
  • Nitrogen/metabolism
  • Peptides/metabolism
  • Rumen/drug effects
  • Sheep/metabolism

Cite this

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title = "Effects of the ionophore tetronasin on nitrogen metabolism by ruminal microorganisms in vitro",
abstract = "The effects of tetronasin on ruminal protein metabolism were investigated in vitro using ruminal fluid from cattle receiving tetronasin in the diet, ovine ruminal fluid from animals not receiving tetronasin and pure cultures of proteolytic ruminal bacteria. Ruminal fluid from cattle receiving tetronasin in a predominantly barley diet had lower proteolytic (76{\%} of control, P less than .10) and deaminative (58{\%} of control, P less than .05) activities than controls after 42 d. The effect of deamination disappeared after 84 d, although the proteolytic activity remained lower (P less than .10) than that of controls. When tetronasin was added in vitro to ruminal fluid from sheep not receiving the ionophore, proteolytic activity (14C-labeled casein hydrolysis) was unaffected, but the rate of ammonia production from amino acids was decreased by 87{\%} (P less than .01). Oligopeptide breakdown was inhibited to a lesser extent (21{\%}, P less than .05). Dipeptidase activity (dialanine hydrolysis) was not affected. The addition of tetronasin to cultures of the ruminal bacteria Ruminobacter amylophilus and Bacteroides ruminicola had no influence on their protease, deaminase or dipeptidase activities. However, when the bacteria were adapted to grow in the presence of tetronasin, deamination of amino acids was severely inhibited (87 to 100{\%}, P less than .01), even when tetronasin was absent from the incubation mixture. Tetronasin had no effect on the proteolytic activity of adapted cultures.(ABSTRACT TRUNCATED AT 250 WORDS)",
keywords = "Amino Acids/metabolism, Animals, Anti-Bacterial Agents/pharmacology, Bacteria/drug effects, Caseins/metabolism, Cattle/metabolism, Dietary Proteins/metabolism, Furans/pharmacology, Ionophores/pharmacology, Nitrogen/metabolism, Peptides/metabolism, Rumen/drug effects, Sheep/metabolism",
author = "Newbold, {C J} and Wallace, {R J} and N McKain",
year = "1990",
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language = "English",
volume = "68",
pages = "1103--9",
journal = "Journal of Animal Science",
issn = "0021-8812",
publisher = "American Society of Animal Science",
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}

Effects of the ionophore tetronasin on nitrogen metabolism by ruminal microorganisms in vitro. / Newbold, C J; Wallace, R J; McKain, N.

In: Journal of Animal Science, Vol. 68, No. 4, 04.1990, p. 1103-9.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effects of the ionophore tetronasin on nitrogen metabolism by ruminal microorganisms in vitro

AU - Newbold, C J

AU - Wallace, R J

AU - McKain, N

PY - 1990/4

Y1 - 1990/4

N2 - The effects of tetronasin on ruminal protein metabolism were investigated in vitro using ruminal fluid from cattle receiving tetronasin in the diet, ovine ruminal fluid from animals not receiving tetronasin and pure cultures of proteolytic ruminal bacteria. Ruminal fluid from cattle receiving tetronasin in a predominantly barley diet had lower proteolytic (76% of control, P less than .10) and deaminative (58% of control, P less than .05) activities than controls after 42 d. The effect of deamination disappeared after 84 d, although the proteolytic activity remained lower (P less than .10) than that of controls. When tetronasin was added in vitro to ruminal fluid from sheep not receiving the ionophore, proteolytic activity (14C-labeled casein hydrolysis) was unaffected, but the rate of ammonia production from amino acids was decreased by 87% (P less than .01). Oligopeptide breakdown was inhibited to a lesser extent (21%, P less than .05). Dipeptidase activity (dialanine hydrolysis) was not affected. The addition of tetronasin to cultures of the ruminal bacteria Ruminobacter amylophilus and Bacteroides ruminicola had no influence on their protease, deaminase or dipeptidase activities. However, when the bacteria were adapted to grow in the presence of tetronasin, deamination of amino acids was severely inhibited (87 to 100%, P less than .01), even when tetronasin was absent from the incubation mixture. Tetronasin had no effect on the proteolytic activity of adapted cultures.(ABSTRACT TRUNCATED AT 250 WORDS)

AB - The effects of tetronasin on ruminal protein metabolism were investigated in vitro using ruminal fluid from cattle receiving tetronasin in the diet, ovine ruminal fluid from animals not receiving tetronasin and pure cultures of proteolytic ruminal bacteria. Ruminal fluid from cattle receiving tetronasin in a predominantly barley diet had lower proteolytic (76% of control, P less than .10) and deaminative (58% of control, P less than .05) activities than controls after 42 d. The effect of deamination disappeared after 84 d, although the proteolytic activity remained lower (P less than .10) than that of controls. When tetronasin was added in vitro to ruminal fluid from sheep not receiving the ionophore, proteolytic activity (14C-labeled casein hydrolysis) was unaffected, but the rate of ammonia production from amino acids was decreased by 87% (P less than .01). Oligopeptide breakdown was inhibited to a lesser extent (21%, P less than .05). Dipeptidase activity (dialanine hydrolysis) was not affected. The addition of tetronasin to cultures of the ruminal bacteria Ruminobacter amylophilus and Bacteroides ruminicola had no influence on their protease, deaminase or dipeptidase activities. However, when the bacteria were adapted to grow in the presence of tetronasin, deamination of amino acids was severely inhibited (87 to 100%, P less than .01), even when tetronasin was absent from the incubation mixture. Tetronasin had no effect on the proteolytic activity of adapted cultures.(ABSTRACT TRUNCATED AT 250 WORDS)

KW - Amino Acids/metabolism

KW - Animals

KW - Anti-Bacterial Agents/pharmacology

KW - Bacteria/drug effects

KW - Caseins/metabolism

KW - Cattle/metabolism

KW - Dietary Proteins/metabolism

KW - Furans/pharmacology

KW - Ionophores/pharmacology

KW - Nitrogen/metabolism

KW - Peptides/metabolism

KW - Rumen/drug effects

KW - Sheep/metabolism

M3 - Article

C2 - 2332385

VL - 68

SP - 1103

EP - 1109

JO - Journal of Animal Science

JF - Journal of Animal Science

SN - 0021-8812

IS - 4

ER -