Nitrate and Inhibition of Ruminal Methanogenesis

Microbial Ecology, Obstacles, and Opportunities for Lowering Methane Emissions from Ruminant Livestock

Chengjian Yang, John A. Rooke, Irene Cabeza, Robert J. Wallace

Research output: Contribution to journalLiterature review

28 Citations (Scopus)
4 Downloads (Pure)

Abstract

Ruminal methane production is among the main targets for greenhouse gas (GHG) mitigation for the animal agriculture industry. Many compounds have been evaluated for their efficacy to suppress enteric methane production by ruminal microorganisms. Of these, nitrate as an alternative hydrogen sink has been among the most promising, but it suffers from variability in efficacy for reasons that are not understood. The accumulation of nitrite, which is poisonous when absorbed into the animal's circulation, is also variable and poorly understood. This review identifies large gaps in our knowledge of rumen microbial ecology that handicap the further development and safety of nitrate as a dietary additive. Three main bacterial species have been associated historically with ruminal nitrate reduction, namely Wolinella succinogenes, Veillonella parvula, and Selenomonas ruminantium, but others almost certainly exist in the largely uncultivated ruminal microbiota. Indications are strong that ciliate protozoa can reduce nitrate, but the significance of their role relative to bacteria is not known. The metabolic fate of the reduced nitrate has not been studied in detail. It is important to be sure that nitrate metabolism and efforts to enhance rates of nitrite reduction do not lead to the evolution of the much more potent GHG, nitrous oxide. The relative importance of direct inhibition of archaeal methanogenic enzymes by nitrite or the efficiency of capture of hydrogen by nitrate reduction in lowering methane production is also not known, nor are nitrite effects on other members of the microbiota. How effective would combining mitigation methods be, based on our understanding of the effects of nitrate and nitrite on the microbiome? Answering these fundamental microbiological questions is essential in assessing the potential of dietary nitrate to limit methane emissions from ruminant livestock.

Original languageEnglish
Article number132
Pages (from-to)1-14
Number of pages14
JournalFrontiers in Microbiology
Volume7
DOIs
Publication statusPublished - 12 Feb 2016

Fingerprint

Methane
Ruminants
Livestock
Ecology
Nitrates
Nitrites
Microbiota
Hydrogen
Wolinella
Selenomonas
Gases
Veillonella
Rumen
Nitrous Oxide
Agriculture
Industry
Bacteria
Safety
Enzymes

Keywords

  • animal health
  • animal performance
  • greenhouse gas
  • nitrate reduction
  • nitrite

Cite this

Nitrate and Inhibition of Ruminal Methanogenesis : Microbial Ecology, Obstacles, and Opportunities for Lowering Methane Emissions from Ruminant Livestock. / Yang, Chengjian; Rooke, John A.; Cabeza, Irene; Wallace, Robert J.

In: Frontiers in Microbiology, Vol. 7, 132, 12.02.2016, p. 1-14.

Research output: Contribution to journalLiterature review

@article{b4fd6467d2ea481e8e1f157c9ae01fa6,
title = "Nitrate and Inhibition of Ruminal Methanogenesis: Microbial Ecology, Obstacles, and Opportunities for Lowering Methane Emissions from Ruminant Livestock",
abstract = "Ruminal methane production is among the main targets for greenhouse gas (GHG) mitigation for the animal agriculture industry. Many compounds have been evaluated for their efficacy to suppress enteric methane production by ruminal microorganisms. Of these, nitrate as an alternative hydrogen sink has been among the most promising, but it suffers from variability in efficacy for reasons that are not understood. The accumulation of nitrite, which is poisonous when absorbed into the animal's circulation, is also variable and poorly understood. This review identifies large gaps in our knowledge of rumen microbial ecology that handicap the further development and safety of nitrate as a dietary additive. Three main bacterial species have been associated historically with ruminal nitrate reduction, namely Wolinella succinogenes, Veillonella parvula, and Selenomonas ruminantium, but others almost certainly exist in the largely uncultivated ruminal microbiota. Indications are strong that ciliate protozoa can reduce nitrate, but the significance of their role relative to bacteria is not known. The metabolic fate of the reduced nitrate has not been studied in detail. It is important to be sure that nitrate metabolism and efforts to enhance rates of nitrite reduction do not lead to the evolution of the much more potent GHG, nitrous oxide. The relative importance of direct inhibition of archaeal methanogenic enzymes by nitrite or the efficiency of capture of hydrogen by nitrate reduction in lowering methane production is also not known, nor are nitrite effects on other members of the microbiota. How effective would combining mitigation methods be, based on our understanding of the effects of nitrate and nitrite on the microbiome? Answering these fundamental microbiological questions is essential in assessing the potential of dietary nitrate to limit methane emissions from ruminant livestock.",
keywords = "animal health, animal performance, greenhouse gas, nitrate reduction, nitrite",
author = "Chengjian Yang and Rooke, {John A.} and Irene Cabeza and Wallace, {Robert J.}",
note = "Acknowledgments CY was supported by a scholarship from the China Scholarship Council. IC was supported by the SRUC International Engagement Strategy Fund. The nitrate project was funded by EBLEX, a Division of the Agriculture and Horticulture Development Board. RINH and SRUC are funded by the Rural and Environment Science and Analytical Services Division (RESAS) of the Scottish Government.",
year = "2016",
month = "2",
day = "12",
doi = "10.3389/fmicb.2016.00132",
language = "English",
volume = "7",
pages = "1--14",
journal = "Frontiers in Microbiology",
issn = "1664-302X",
publisher = "FRONTIERS MEDIA SA",

}

TY - JOUR

T1 - Nitrate and Inhibition of Ruminal Methanogenesis

T2 - Microbial Ecology, Obstacles, and Opportunities for Lowering Methane Emissions from Ruminant Livestock

AU - Yang, Chengjian

AU - Rooke, John A.

AU - Cabeza, Irene

AU - Wallace, Robert J.

N1 - Acknowledgments CY was supported by a scholarship from the China Scholarship Council. IC was supported by the SRUC International Engagement Strategy Fund. The nitrate project was funded by EBLEX, a Division of the Agriculture and Horticulture Development Board. RINH and SRUC are funded by the Rural and Environment Science and Analytical Services Division (RESAS) of the Scottish Government.

PY - 2016/2/12

Y1 - 2016/2/12

N2 - Ruminal methane production is among the main targets for greenhouse gas (GHG) mitigation for the animal agriculture industry. Many compounds have been evaluated for their efficacy to suppress enteric methane production by ruminal microorganisms. Of these, nitrate as an alternative hydrogen sink has been among the most promising, but it suffers from variability in efficacy for reasons that are not understood. The accumulation of nitrite, which is poisonous when absorbed into the animal's circulation, is also variable and poorly understood. This review identifies large gaps in our knowledge of rumen microbial ecology that handicap the further development and safety of nitrate as a dietary additive. Three main bacterial species have been associated historically with ruminal nitrate reduction, namely Wolinella succinogenes, Veillonella parvula, and Selenomonas ruminantium, but others almost certainly exist in the largely uncultivated ruminal microbiota. Indications are strong that ciliate protozoa can reduce nitrate, but the significance of their role relative to bacteria is not known. The metabolic fate of the reduced nitrate has not been studied in detail. It is important to be sure that nitrate metabolism and efforts to enhance rates of nitrite reduction do not lead to the evolution of the much more potent GHG, nitrous oxide. The relative importance of direct inhibition of archaeal methanogenic enzymes by nitrite or the efficiency of capture of hydrogen by nitrate reduction in lowering methane production is also not known, nor are nitrite effects on other members of the microbiota. How effective would combining mitigation methods be, based on our understanding of the effects of nitrate and nitrite on the microbiome? Answering these fundamental microbiological questions is essential in assessing the potential of dietary nitrate to limit methane emissions from ruminant livestock.

AB - Ruminal methane production is among the main targets for greenhouse gas (GHG) mitigation for the animal agriculture industry. Many compounds have been evaluated for their efficacy to suppress enteric methane production by ruminal microorganisms. Of these, nitrate as an alternative hydrogen sink has been among the most promising, but it suffers from variability in efficacy for reasons that are not understood. The accumulation of nitrite, which is poisonous when absorbed into the animal's circulation, is also variable and poorly understood. This review identifies large gaps in our knowledge of rumen microbial ecology that handicap the further development and safety of nitrate as a dietary additive. Three main bacterial species have been associated historically with ruminal nitrate reduction, namely Wolinella succinogenes, Veillonella parvula, and Selenomonas ruminantium, but others almost certainly exist in the largely uncultivated ruminal microbiota. Indications are strong that ciliate protozoa can reduce nitrate, but the significance of their role relative to bacteria is not known. The metabolic fate of the reduced nitrate has not been studied in detail. It is important to be sure that nitrate metabolism and efforts to enhance rates of nitrite reduction do not lead to the evolution of the much more potent GHG, nitrous oxide. The relative importance of direct inhibition of archaeal methanogenic enzymes by nitrite or the efficiency of capture of hydrogen by nitrate reduction in lowering methane production is also not known, nor are nitrite effects on other members of the microbiota. How effective would combining mitigation methods be, based on our understanding of the effects of nitrate and nitrite on the microbiome? Answering these fundamental microbiological questions is essential in assessing the potential of dietary nitrate to limit methane emissions from ruminant livestock.

KW - animal health

KW - animal performance

KW - greenhouse gas

KW - nitrate reduction

KW - nitrite

U2 - 10.3389/fmicb.2016.00132

DO - 10.3389/fmicb.2016.00132

M3 - Literature review

VL - 7

SP - 1

EP - 14

JO - Frontiers in Microbiology

JF - Frontiers in Microbiology

SN - 1664-302X

M1 - 132

ER -