2026-04-17T07:34:49Zhttps://recercat.cat/oai/request

oai:recercat.cat:10459.1/492232024-12-05T22:18:31Zcom_2072_3622col_2072_479130

00925njm 22002777a 4500 dc Belanche, A. author de la Fuente Oliver, Gabriel author Newbold, C. Jamie author 2015-12-02T18:39:37Z 2015-12-02T18:39:37Z 2015-01-08 2015-12-02T18:39:37Z Protozoa-associated methanogens (PAM) are considered one of the most active communities in the rumen methanogenesis. This experiment investigated whether methanogens are sequestrated within rumen protozoa, and structural differences between rumen free-living methanogens and PAM. Rumen protozoa were harvested from totally faunated sheep, and six protozoal fractions (plus free-living microorganisms) were generated by sequential filtration. Holotrich-monofaunated sheep were also used to investigate the holotrich-associated methanogens. Protozoal size determined the number of PAM as big protozoa had 1.7<br>3.3 times more methanogen DNA than smaller protozoa, but also more endosymbiotic bacteria (2.2- to 3.5-fold times). Thus, similar abundance of methanogens with respect to total bacteria were observed across all protozoal fractions and free-living microorganisms, suggesting that methanogens are not accumulated within rumen protozoa in a greater proportion to that observed in the rumen as a whole. All rumen methanogen communities had similar diversity (22.2 ± 3.4 TRFs). Free-living methanogens composed a conserved community (67% similarity within treatment) in the rumen with similar diversity but different structures than PAM (P< 0.05). On the contrary, PAM constituted a more variable community (48% similarity), which differed between holotrich and total protozoa (P< 0.001). Thus, PAM constitutes a community, which requires further investigation as part of methane mitigation strategies. This work was supported by the Commission of the European Communities (REDNEX project FP7-KBBE-2007-1) and the Welsh Government. http://hdl.handle.net/10459.1/49223 archaea endosymbiotic holotrich methanogens rumen protozoa Remugants Protozous Ruminants Protozoa Study of methanogen communities associated with different rumen protozoal populations