Ecological Differentiation in Two Major Freshwater Bacterial Taxa Along Environmental Gradients
Ecological Differentiation in Two Major Freshwater Bacterial Taxa Along Environmental Gradients
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DOI：
10.3389/fmicb.2020.00154
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发表时间：
2020-02-13
影响因子：
5.2
通讯作者：
Boenigk, Jens
中科院分区：
文献类型：
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作者：
Nuy, Julia K.;Hoetzinger, Matthias;Boenigk, Jens
多核杆菌（burkholderaceae, Betaproteobacteria）和Limnohabitans （Comamonadaceae, Betaproteobacteria）是丰富的淡水细菌，具有很大的遗传和分类多样性，其物种适应于物理化学不同类型的淡水系统。环境驱动因素，即物理化学、微真核生物的存在和地理位置对这两个分类群的多样性和流行率的相对重要性尚未得到研究。在这里，我们提出了关于这一主题的第一个泛欧研究，包括255个淡水湖。我们利用沿环境梯度的部分16S rRNA基因扩增子测序方法研究了Limnohabitans和Polynucleobacter。我们发现，物理化学因素对两属的影响最大。对环境梯度的分析揭示了一个异常广泛的生态光谱的操作分类单位（otu）。尽管遗传标记的分辨率很低，但我们在Polynucleobacter和Limnohabitans亚群中发现了具有不同环境偏好的otu。这种生态分化已经在PnecC和LimC中得到了表征，但迄今为止对PnecA和PnecB等研究较少的亚群尚不清楚。otu的丰富度和丰度在地理上呈聚类，表明地理多样性格局是由区域特定的物理化学特征（如pH和温度）而不是纬度梯度或湖泊大小决定的。
Polynucleobacter (Burkholderiaceae, Betaproteobacteria) and Limnohabitans (Comamonadaceae, Betaproteobacteria) are abundant freshwater bacteria comprising large genetic and taxonomic diversities, with species adapted to physico-chemically distinct types of freshwater systems. The relative importance of environmental drivers, i.e., physico-chemistry, presence of microeukaryotes and geographic position for the diversity and prevalence has not been investigated for both taxa before. Here, we present the first pan-European study on this topic, comprising 255 freshwater lakes. We investigated Limnohabitans and Polynucleobacter using an amplicon sequencing approach of partial 16S rRNA genes along environmental gradients. We show that physico-chemical factors had the greatest impact on both genera. Analyses on environmental gradients revealed an exceptionally broad ecological spectrum of operational taxonomic units (OTUs). Despite the coarse resolution of the genetic marker, we found OTUs with contrasting environmental preferences within Polynucleobacter and Limnohabitans subclusters. Such an ecological differentiation has been characterized for PnecC and LimC before but was so far unknown for less well studied subclusters such as PnecA and PnecB. Richness and abundance of OTUs are geographically clustered, suggesting that geographic diversity patterns are attributable to region-specific physico-chemical characteristics (e.g., pH and temperature) rather than latitudinal gradients or lake sizes.