The metabolic pathways involved in hydrogen ($H_2$) production, utilization and the activity of methanogens are the important factors that should be considered in controlling methane ($CH_4$) emissions by ruminants. $H_2$ as one of the major substrate for $CH_4$ production is therefore should be controlled. One of the strategies on reducing $CH_4$ is through the use of hydrogenotrophic microorganisms such as fumarate reducing bacteria. This study determined the effect of fumarate reducing bacteria, Mitsuokella jalaludinii, supplementation on in vitro rumen fermentation, $CH_4$ production, diversity and quantity. M. jalaludinii significantly reduced $CH_4$ at 48 and 72 h of incubation and significantly increased succinate at 24 h. Although not significantly different, propionate was found to be highest in treatment containing M. jalaludinii at 12 and 48 h of incubation. These results suggest that supplementation of fumarate reducing bacteria to ruminal fermentation reduces $CH_4$ production and quantity, increases succinate and changes the rumen microbial diversity.