METHANOGENS ASSOCIATED WITH RUMEN CILIATES

Methanogenesis per ciliate protozoan and most probable numbers (MPN) o f methanogens per ciliate were measured and observed to be affected by feeding. The close similarity observed between the changes in apparen t methane production and the changes in the number of methanogens per ciliate indicated that apparent methane production by ciliates depende d primarily on the number of methanogens associated with them. Large c hanges in the MPN of methanogens associated with ciliates occurred rap idly. It is likely that these changes reflect the number of methanogen s that associated extracellularly with the ciliates. Methanogens assoc iated with ciliates may have differed from the free living methanogens in halophilism and their resistance to ammonium ions.