Effect of ruminal administration of Escherichia coli wild type or a genetically modified strain with enhanced high nitrite reductase activity on methane emission and nitrate toxicity in nitrate-infused sheep

• Published in: British journal of nutrition 2005-11, Vol.94 (5), p.691-697
• Main Authors: Sar, C., Mwenya, B., Pen, B., Takaura, K., Morikawa, R., Tsujimoto, A., Kuwaki, K., Isogai, N., Shinzato, I., Asakura, Y., Toride, Y., Takahashi, J.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blood; Body weight; Carbon Dioxide - metabolism; Degeneration. Regeneration. Wound healing. Graft; E coli; Emissions; enzyme activity; Escherichia coli; Escherichia coli - enzymology; Escherichia coli - genetics; Escherichia coli - physiology; Escherichia coli nir-Ptac; Escherichia coli W3110; Fermentation; Fundamental and applied biological sciences. Psychology; Infusions, Parenteral - methods; Male; Metabolic Clearance Rate; Metabolism; Methane; Methane - metabolism; Methane emission; methane production; Methanogenesis; Methemoglobin - analysis; Nitrate; Nitrate Reductase - metabolism; nitrate reduction; Nitrates; Nitrates - administration & dosage; Nitrates - adverse effects; Nitrates - pharmacokinetics; nitric oxide; nitrite reductase; Nitrites - blood; Nitrites - pharmacokinetics; Nitrogen dioxide; Oxygen Consumption - physiology; Protozoa; Rumen - microbiology; rumen bacteria; rumen fermentation; Ruminantia; serotypes; Sheep; sheep feeding; Toxicity; Vertebrates: anatomy and physiology, studies on body, several organs or systems; wild relatives
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN20051517

The effects of two kinds of Escherichia coli (E. coli) strain, wild-type E. coli W3110 and E. coli nir-Ptac, which has enhanced NO2 reduction activity, on oral CH4 emission and NO3 toxicity in NO3-treated sheep were assessed in a respiratory hood system in a 4×6 Youden square design. NO3 (1·3g NaNO3/kg0·75 body weight) and/or E. coli strains were delivered into the rumen through a fistula as a single dose 30min after the morning meal. Escherichia coli cells were inoculated for sheep to provide an initial E. coli cell density of optical density at 660nm of 2, which corresponded to 2×1010 cells/ml. The six treatments consisted of saline, E. coli W3110, E. coli nir-Ptac, NO3, NO3 plus E. coli W3110, and NO3 plus E. coli nir-Ptac. CH4 emission from sheep was reduced by the inoculation of E. coli W3110 or E. coli nir-Ptac by 6% and 12%, respectively. NO3 markedly inhibited CH4 emission from sheep. Compared with sheep given NO3 alone, the inoculation of E. coli W3110 to NO3-infused sheep lessened ruminal and plasma toxic NO2 accumulation and blood methaemoglobin production, while keeping ruminal methanogenesis low. Ruminal and plasma toxic NO2 accumulation and blood methaemoglobin production in sheep were unaffected by the inoculation of E. coli nir-Ptac. These results suggest that ruminal methanogenesis may be reduced by the inoculation of E. coli W3110 or E. coli nir-Ptac. The inoculation of E. coli W3110 may abate NO3 toxicity when NO3 is used to inhibit CH4 emission from ruminants.