Activity of abundant and rare bacteria in a coastal ocean
Activity of abundant and rare bacteria in a coastal ocean
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DOI：
10.1073/pnas.1101405108
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发表时间：
2011-08-02
影响因子：
11.1
通讯作者：
Kirchman, David L.
中科院分区：
文献类型：
--
作者：
Campbell, Barbara J.;Yu, Liying;Kirchman, David L.
海洋和其他水生环境的表层含有许多活动范围广泛的细菌，从休眠细胞到高代谢率的细胞。然而，关于特定细菌分类群，特别是罕见细菌分类群活性的实验证据很少。在这里，我们通过记录丰度随时间的变化以及通过检测单个细菌分类群的16S rRNA与rRNA基因（rDNA）的比例来探索丰度与活性之间的关系。采用标记焦磷酸测序法对美国特拉华州沿海地表水的16S rRNA和rDNA的V1-V2区进行了分析。超过一半的细菌分类群活跃地在丰富和稀有之间循环，而大约12%的细菌分类群始终保持稀有和潜在的非活性。在大多数分类群中，16S rRNA的相对丰度与16S rDNA的相对丰度呈显著相关。然而，在大约20%的分类群中，16S rRNA: rDNA比值在它们稀少时明显高于丰富时。通过定量PCR方法确定了5个分类群中16S rRNA与rDNA频率之间的关系。我们的研究结果表明，尽管在大多数分类群中，丰度随活动而变化，但有很大一部分稀有群落是活跃的，其增长率随着丰度的增加而降低。
The surface layer of the oceans and other aquatic environments contains many bacteria that range in activity, from dormant cells to those with high rates of metabolism. However, little experimental evidence exists about the activity of specific bacterial taxa, especially rare ones. Here we explore the relationship between abundance and activity by documenting changes in abundance over time and by examining the ratio of 16S rRNA to rRNA genes (rDNA) of individual bacterial taxa. The V1-V2 region of 16S rRNA and rDNA was analyzed by tag pyrosequencing in a 3-y study of surface waters off the Delaware coast. Over half of the bacterial taxa actively cycled between abundant and rare, whereas about 12% always remained rare and potentially inactive. There was a significant correlation between the relative abundance of 16S rRNA and the relative abundance of 16S rDNA for most individual taxa. However, 16S rRNA: rDNA ratios were significantly higher in about 20% of the taxa when they were rare than when abundant. Relationships between 16S rRNA and rDNA frequencies were confirmed for five taxa by quantitative PCR. Our findings suggest that though abundance follows activity in the majority of the taxa, a significant portion of the rare community is active, with growth rates that decrease as abundance increases.