Sundset Monica A, Edwards Joan E, Cheng Yan Fen, Senosiain Roberto S, Fraile Maria N, Northwood Korinne S, Praesteng Kirsti E, Glad Trine, Mathiesen Svein D, Wright André-Denis G
Department of Arctic Biology and Institute of Medical Biology, University of Tromsø, 9037, Tromsø, Norway.
Microb Ecol. 2009 Feb;57(2):335-48. doi: 10.1007/s00248-008-9414-7. Epub 2008 Jul 8.
The molecular diversity of the rumen microbiome was investigated in five semi-domesticated adult female Norwegian reindeer (Rangifer tarandus tarandus) grazing on natural summer pastures on the coast of northern Norway (71.00 degrees N, 25.30 degrees E). Mean population densities (numbers per gram wet weight) of methanogenic archaea, rumen bacteria and ciliate protozoa, estimated using quantitative real-time polymerase chain reaction (PCR), were 3.17x10(9), 5.17x10(11) and 4.02x10(7), respectively. Molecular diversity of rumen methanogens was revealed using a 16S rRNA gene library (54 clones) constructed using pooled PCR products from the whole rumen contents of the five individual reindeer. Based upon a similarity criterion of <97%, a total of 19 distinct operational taxonomic units (OTUs) were identified, nine of which are potential new species. The 16S rRNA sequences generated from the reindeer rumen exhibited a high degree of sequence similarity to methanogens affiliated with the families Methanobacteriaceae (14 OTUs) and Methanosarcinaceae (one OTU). Four of the OTUs detected belonged to a group of uncultivated archaea previously found in domestic ruminants and thought to be dominant in the rumen together with Methanobrevibacter spp. Denaturing gradient gel electrophoresis profiling of the rumen bacterial 16S rRNA gene and the protozoal 18S rRNA gene indicated a high degree of animal variation, although some bands were common to all individuals. Automated ribosomal intergenic spacer analysis (ARISA) profiling of the ruminal Neocallimastigales population indicated that the reindeer are likely to contain more than one type of anaerobic fungus. The ARISA profile from one animal was distinct from the other four. This is the first molecular investigation of the ruminal methanogenic archaea in reindeer, revealing higher numbers than expected based on methane emission data available. Also, many of the reindeer archaeal 16S rRNA gene sequences were similar to those reported in domesticated ruminants in Australia, Canada, China, New Zealand and Venezuela, supporting previous findings that there seems to be no host type or geographical effect on the methanogenic archaea community structure in ruminants.
对五只半驯化的成年挪威雌性驯鹿（Rangifer tarandus tarandus）的瘤胃微生物群的分子多样性进行了研究，这些驯鹿在挪威北部海岸（北纬71.00度，东经25.30度）的天然夏季牧场上放牧。使用定量实时聚合酶链反应（PCR）估计，产甲烷古菌、瘤胃细菌和纤毛虫原生动物的平均种群密度（每克湿重的数量）分别为3.17×10⁹、5.17×10¹¹和4.02×10⁷。使用从五只驯鹿个体的整个瘤胃内容物中汇集的PCR产物构建的16S rRNA基因文库（54个克隆）揭示了瘤胃产甲烷菌的分子多样性。基于<97%的相似性标准，共鉴定出19个不同的操作分类单元（OTU），其中九个可能是新物种。从驯鹿瘤胃产生的16S rRNA序列与甲烷杆菌科（14个OTU）和甲烷八叠球菌科（1个OTU）的产甲烷菌表现出高度的序列相似性。检测到的四个OTU属于一组以前在反刍家畜中发现的未培养古菌，并且被认为与短甲烷杆菌属一起在瘤胃中占主导地位。瘤胃细菌16S rRNA基因和原生动物18S rRNA基因的变性梯度凝胶电泳分析表明，尽管有些条带对所有个体来说是共同的，但动物之间存在高度差异。瘤胃新美鞭菌门种群的自动核糖体基因间隔区分析（ARISA）表明，驯鹿可能含有不止一种类型的厌氧真菌。一只动物的ARISA图谱与其他四只不同。这是对驯鹿瘤胃产甲烷古菌的首次分子研究，结果表明其数量比基于现有甲烷排放数据预期的要多。此外，许多驯鹿古菌16S rRNA基因序列与澳大利亚、加拿大、中国、新西兰和委内瑞拉的家养反刍家畜中报道的序列相似，这支持了先前的研究结果，即反刍家畜的产甲烷古菌群落结构似乎没有宿主类型或地理效应。
