Phylogenetic diversity and dietary association of rumen Treponema revealed using group-specific 16S rRNA gene-based analysis
Phylogenetic diversity and dietary association of rumen Treponema revealed using group-specific 16S rRNA gene-based analysis
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DOI：
10.1111/j.1574-6968.2010.02191.x
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发表时间：
2011-03-01
影响因子：
2.1
通讯作者：
Kobayashi, Yasuo
中科院分区：
文献类型：
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作者：
Bekele, Aschalew Z.;Koike, Satoshi;Kobayashi, Yasuo
密螺旋体属是瘤胃中常见的细菌群，参与可溶性纤维的降解。在本研究中，设计了针对 16S rRNA 基因的瘤胃密螺旋体群体特异性 PCR 引物，并用于评估绵羊瘤胃中该群体的系统发育多样性和饮食关联。从三只以苜蓿/果园草干草或浓缩物喂养的羊的瘤胃食糜中提取总 DNA。实时PCR定量表明，瘤胃细菌中密螺旋体群的相对丰度高达1.05%，而已知种布氏密螺旋体仅占0.02%。通过 16S rDNA 靶向变性梯度凝胶电泳 (DGGE) 分析确定的密螺旋体群落指纹在不同饮食中往往有所不同。 DGGE 谱的主成分分析区分了与干草或浓缩饲料相关的密螺旋体。对密螺旋体 16S rRNA 基因克隆文库的分析表明，特定饮食条件下存在系统发育上不同的操作分类单位，并且在根据每种饮食方案构建的克隆文库中观察到群落组成的显着差异（P = 0.001）。大多数克隆 (75.4%) 与已知密螺旋体的序列相似性 < 97%。这些结果表明，未培养的密螺旋体占主导地位，它们似乎具有与干草或浓缩饲料消化相关的独特成员。
Treponema spp. are a commonly detected bacterial group in the rumen that are involved in the degradation of soluble fibers. In this study, a ruminal Treponema group-specific PCR primer targeting the 16S rRNA gene was designed and used to assess the phylogenetic diversity and diet association of this group in sheep rumen. Total DNA was extracted from rumen digesta of three sheep fed a diet based on alfalfa/orchardgrass hay or concentrate. The real-time PCR quantification indicated that the relative abundance of the Treponema group in the total rumen bacteria was as high as 1.05%, while the known species Treponema bryantii accounted for only 0.02%. Fingerprints of the Treponema community determined by 16S rDNA-targeted denaturing gradient gel electrophoresis (DGGE) analysis tended to differ among the diets. Principal component analysis of the DGGE profiles distinguished those Treponema associated with either the hay or the concentrate diets. Analysis of a Treponema 16S rRNA gene clone library showed phylogenetically distinct operational taxonomic units for a specific dietary condition, and significant (P=0.001) differences in community composition were observed among clone libraries constructed from each dietary regimen. The majority of clones (75.4%) had < 97% sequence similarity with known Treponema. These results suggest the predominance of uncultured Treponema that appear to have distinct members related to the digestion of either hay or concentrate diet.