Archaeal Abundance across a pH Gradient in an Arable Soil and Its Relationship to Bacterial and Fungal Growth Rates
Archaeal Abundance across a pH Gradient in an Arable Soil and Its Relationship to Bacterial and Fungal Growth Rates
复制标题
DOI：
10.1128/aem.01476-12
复制
发表时间：
2012-08-01
影响因子：
4.4
通讯作者：
Rousk, Johannes
中科院分区：
文献类型：
--
作者：
Bengtson, Per;Sterngren, Anna E.;Rousk, Johannes
土壤pH是影响细菌和真菌群落组成的最重要因素之一，但土壤pH对土壤古生物群落分布和组成的影响尚未得到系统的研究。这项研究的主要目的是确定在pH梯度(pH 4.0到8.3)范围内，古菌总丰度(基于定量PCR[qPCR]估计的16S rRNA基因拷贝数)与土壤pH之间的关系。其次，我们想要评估在相同的pH梯度下，古生菌的丰度如何与细菌和真菌的生长速度相关。我们发现pH对古生菌丰度有两种截然不同且相反的影响。在最低pH范围内(pH 4.0~4.7)，古细菌的丰度似乎与pH不一致。在这个pH范围以上，古生物的丰度急剧下降，几乎减少了4倍，在pH 5.1至5.2时降至最低。古细菌16S rRNA基因拷贝数在此pH范围内丰度较低，随着pH的升高，16S rRNA基因拷贝数急剧增加近150倍，导致古细菌和细菌拷贝数之比从最小的0.002增加到pH 8时的0.07以上。古菌对pH的不均匀响应反映了古菌群落组成沿梯度的变化，一些古菌适应酸性条件，另一些适应中性到弱碱性条件。古生菌、细菌和真菌之间朝着所研究的pH梯度的低端和高端的(竞争性)相互作用的对比结果的观察加强了这一观点。
Soil pH is one of the most influential factors for the composition of bacterial and fungal communities, but the influence of soil pH on the distribution and composition of soil archaeal communities has yet to be systematically addressed. The primary aim of this study was to determine how total archaeal abundance (quantitative PCR [qPCR]-based estimates of 16S rRNA gene copy numbers) is related to soil pH across a pH gradient (pH 4.0 to 8.3). Secondarily, we wanted to assess how archaeal abundance related to bacterial and fungal growth rates across the same pH gradient. We identified two distinct and opposite effects of pH on the archaeal abundance. In the lowest pH range (pH 4.0 to 4.7), the abundance of archaea did not seem to correspond to pH. Above this pH range, there was a sharp, almost 4-fold decrease in archaeal abundance, reaching a minimum at pH 5.1 to 5.2. The low abundance of archaeal 16S rRNA gene copy numbers at this pH range then sharply increased almost 150-fold with pH, resulting in an increase in the ratio between archaeal and bacterial copy numbers from a minimum of 0.002 to more than 0.07 at pH 8. The nonuniform archaeal response to pH could reflect variation in the archaeal community composition along the gradient, with some archaea adapted to acidic conditions and others to neutral to slightly alkaline conditions. This suggestion is reinforced by observations of contrasting outcomes of the (competitive) interactions between archaea, bacteria, and fungi toward the lower and higher ends of the examined pH gradient.