Using strains of Propionibacteria to mitigate methane emissions in vitro

Abstract

Sixteen strains of propionibacteria were inoculated into in vitro ruminal incubations to evaluate their potential to reduce methane (CH₄) production from concentrate and forage diets. Propionibacterium freudenreichii T114, Propionibacterium thoenii T159, and Propionibacterium thoenii ATCC 4874 lowered (p < 0.05) CH₄ production from both substrates compared to control. Compared to control, Propionibacterium jensenii T1, Propionibacterium freudenreichii T31, and Propionibacterium freudenreichii T54 lowered (p < 0.05) CH₄ production only with corn. Propionibacterium propionicus T83 caused higher (p < 0.05) propionate percentage and lower (p < 0.05) acetate:propionate than the control with corn; however, this did not result in a decline in CH₄ production. Results demonstrate that some strains of propionibacteria have the potential to lower CH₄ production from mixed ruminal cultures and that this reduction is not always associated with an increase in propionate production.

Keywords:

• In vitro
• methane
• propionibacteria
• rumen
• volatile fatty acids

Acknowledgments

This study was conducted with funding from the Feed Opportunities in the Biofuels Industry (FOBI) network of the AAFC Agricultural Bioproducts Innovation Program (AABIP), the Alberta Meat and Livestock Agency (ALMA), and the Norwegian–Canadian BILAT project. The authors thank D. Vedres (chromatography), K. Munns, W. Smart, and G. Wang (technical support) for their contributions to this study.