Abstract
Sixteen strains of propionibacteria were inoculated into in vitro ruminal incubations to evaluate their potential to reduce methane (CH
4
) production from concentrate and forage diets. Propionibacterium freudenreichii T114, Propionibacterium thoenii T159, and Propionibacterium thoenii ATCC 4874 lowered (p < 0.05) CH
4
production from both substrates compared to control. Compared to control, Propionibacterium jensenii T1, Propionibacterium freudenreichii T31, and Propionibacterium freudenreichii T54 lowered (p < 0.05) CH
4
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 CH
4
production. Results demonstrate that some strains of propionibacteria have the potential to lower CH
4
production from mixed ruminal cultures and that this reduction is not always associated with an increase in propionate production.