title: Rumen microbial diversity in Svalbard reindeer, with particular emphasis on methanogenic archaea.
abstract: Ruminal methanogens, bacteria and ciliate protozoa of Svalbard reindeer grazing natural pastures in October (late fall) and April (late winter) were investigated using molecular-based approaches. The appetite of the Svalbard reindeer peaks in August (summer) and is at its lowest in March (winter). Microbial numbers, quantified by real-time PCR, did not change significantly between October and April, when food intakes are at similar levels, although the numbers of methanogens tended to be higher in October (P=0.074), and ciliate numbers tended to be higher in April (P=0.055). Similarly, no change was detected in the bacterial and protozoal population composition by rRNA gene-based denaturing gradient gel electrophoresis analysis. Dominant methanogens were identified using a 16S rRNA gene library (97 clones) prepared from pooled PCR products from reindeer on October pasture (n=5). Eleven of the 22 distinct operational taxonomic units (OTUs) generated exhibited a high degree of sequence similarity to methanogens affiliated with Methanobacteriales (eight OTUs), Methanomicrobiales (one OTU) and Methanosarcinales (two OTUs). The remaining 11 OTUs (53% of the clones) were associated with a cluster of uncultivated ruminal archaea. This study has provided important insights into the rumen microbiome of a high-arctic herbivorous animal living under harsh nutritional conditions, and evidence suggesting that host type affects the population size of ruminal methanogens.
authors.affiliation: Department of Arctic Biology, Institute of Medical Biology, University of Tromsø, Tromsø, Norway. monica.a.sundset@uit.no
authors.forename: Monica A
authors.initials: MA
authors.lastname: Sundset
authors.forename: Joan E
authors.initials: JE
authors.lastname: Edwards
authors.forename: Yan Fen
authors.initials: YF
authors.lastname: Cheng
authors.forename: Roberto S
authors.initials: RS
authors.lastname: Senosiain
authors.forename: Maria N
authors.initials: MN
authors.lastname: Fraile
authors.forename: Korinne S
authors.initials: KS
authors.lastname: Northwood
authors.forename: Kirsti E
authors.initials: KE
authors.lastname: Praesteng
authors.forename: Trine
authors.initials: T
authors.lastname: Glad
authors.forename: Svein D
authors.initials: SD
authors.lastname: Mathiesen
authors.forename: André-Denis G
authors.initials: AD
authors.lastname: Wright
mesh_terms: D056893:Alveolata / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D000818:Animals; D001105:Archaea / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D019641:DNA, Archaeal / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics; D005260:Female; D015723:Gene Library; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012053:Reindeer / Q000382:microbiology*; D012417:Rumen / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D016054:DNA, Protozoan; D012336:RNA, Ribosomal, 16S