Shifts of rumen microbial population detected by real-time PCR when methanogenesis is inhibited

Real-time PCR was conducted to quantify methanogens, bacteria, Fibrobacter succinogenes, Ruminococcus fl avefaciens and fungi in rumen fl uid incubated in vitro when methane synthesis was inhibited.After 24 h incubation, methanogens in sodium salt of 2-bromoethanesulphonic acid (BES)-added fl uids was reduced to 10.4% of control (P<0.01).BES did not signifi cantly infl uence the number of bacteria and R. fl avefaciens.However, the number of F. succinogenes in BES-treated fl uid was 50.0%higher than in control (P<0.01).Population density of fungi fell by 61.9% (P<0.01) in comparison with control.Addition with BES changed the rumen microbiota and had a varying infl uence on different microbes.