Effects of several inhibitors on pure cultures of ruminal methanogens.
OBJECTIVE
To examine the effects of five inhibitors of methanogenesis, 2-bromoethanesulphonate (BES), 3-bromopropanesulphonate (BPS), lumazine, propynoic acid and ethyl 2-butynoate, on CH4 production of the ruminal methanogens Methanobrevibacter ruminantium, Methanosarcina mazei and Methanomicrobium mobile.


RESULTS
Methanogens were grown in MS medium including 25% (v/v) clarified ruminal fluid. Methane production was measured after 4 and 6 days of incubation. Methanobrevibacter ruminantium was the most sensitive species to BES, propynoic acid and ethyl 2-butynoate. Methanosarcina mazei was the least sensitive species to those chemical additives, and Mm. mobile was intermediate. BPS failed to inhibit any of the methanogens. All three species were almost completely inhibited by 50- and 100%-lumazine saturated media, but the inhibition was somewhat lower with a 25%-lumazine saturated media.


CONCLUSIONS
There were important differences among species of methanogens regarding their sensitivity to the different inhibitors. In general, Ms. mazei was the most resistant to inhibitors, Mb. ruminantium the least resistant, and Mm. mobile was intermediate.


CONCLUSIONS
Differences among methanogens regarding their resistance to chemical inhibitors should be considered when designing strategies of inhibition of ruminal methanogenesis, as selection of resistant species may result.
Department of Animal Science, Michigan State University, East Lansing, MI, USA. emu@umd.edu
E M
EM
Ungerfeld
S R
SR
Rust
D R
DR
Boone
Y
Y
Liu
D017738:Alkanesulfonic Acids / Q000378:metabolism; D000480:Alkynes / Q000378:metabolism; D000818:Animals; D002087:Butyrates / Q000378:metabolism; D004352:Drug Resistance, Microbial / Q000502:physiology; D005285:Fermentation; D008697:Methane / Q000037:antagonists & inhibitors*; D019638:Methanomicrobiaceae / Q000378:metabolism*; D011422:Propionates / Q000378:metabolism; D011621:Pteridines / Q000378:metabolism; D012417:Rumen / Q000382:microbiology*; D012418:Ruminants
C495861:3-bromopropanesulfonate; D017738:Alkanesulfonic Acids; D000480:Alkynes; D002087:Butyrates; D011422:Propionates; D011621:Pteridines; C495862:ethyl 2-butynoate; C008297:lumazine; C018853:2-bromoethanesulfonic acid; D008697:Methane; C011537:propiolic acid