Denitrification of Permeable Sand Sediment in a Headwater River Is Mainly Influenced by Water Chemistry, Rather Than Sediment Particle Size and Heterogeneity.
Denitrification of Permeable Sand Sediment in a Headwater River Is Mainly Influenced by Water Chemistry, Rather Than Sediment Particle Size and Heterogeneity.
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源头河流渗透性沙沉积物的反硝化主要受水化学影响，而不是沉积物粒径和非均质性
DOI：
10.3390/microorganisms9112202
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发表时间：
2021-10-22
期刊：
影响因子：
4.5
通讯作者：
Zhang Q
中科院分区：
文献类型：
--
作者：
Wang W;Wang X;Shu X;Wang B;Li H;Zhang Q
沉积物颗粒大小和非均质性通过直接和间接影响物质交换率、环境梯度、微生物生物量和放牧压力，在沉积物反硝化过程中发挥重要作用。然而，这些影响主要是在不透水的沉积物中观察到的。另一方面，可渗透沉积物的物质交换以平流为主，而不是扩散，相对于不透水沉积物，交换或输送速率比扩散速率高两个数量级。可渗透沉积物颗粒大小和非均质性对反硝化的影响仍然知之甚少，特别是在毫米尺度上。在这里，我们进行了现场对照实验，我们将沙子沉积物分成四个均匀粒度的处理和四个非均质处理。每个处理都重复地部署在三个不同的河流段的冲刷中，具有不同的物理化学特征。培养3个月后，测定所有处理的底泥反硝化细菌群落(NIRS、NirK、nosZ)、反硝化基因丰度(NIRS、nirK、nosZ)和反硝化速率。我们发现，可渗透沉积物中的反硝化微生物大多为未分类的反硝化微生物，颗粒大小和异质性与功能基因丰度或反硝化速率没有显著相关性。水化学是透水性沉积物反硝化的关键控制因素。水体NO3-−-N直接调节透水性沉积物的反硝化速率，而不是通过影响沉积物的化学性质间接调节沉积物的反硝化速率。我们的研究填补了源头河流可渗透底泥中反硝化作用的知识空白，并强调了颗粒大小和非均质性对可渗透底泥反硝化作用的影响较小。
Sediment particle size and heterogeneity play an important role in sediment denitrification through direct and indirect effects on, for example, the material exchange rate, environmental gradients, microbial biomass, and grazing pressure. However, these effects have mostly been observed in impermeable sediments. On the other hand, the material exchange of permeable sediments is dominated by advection instead of diffusion, with the exchange or transport rates exceeding those of diffusion by two orders of magnitude relative to impermeable sediments. The impact of permeable sediment particle size and heterogeneity on denitrification remains poorly understood, especially at the millimeter scale. Here, we conducted an in situ control experiment in which we sorted sand sediment into four homogeneous-particle-sizes treatments and four heterogeneous treatments. Each treatment was deployed, in replicate, within the riffle in three different river reaches with contrasting physicochemical characteristics. After incubating for three months, sediment denitrifier communities (nirS, nirK, nosZ), denitrification gene abundances (nirS, nirK, nosZ), and denitrification rates in all treatments were measured. We found that most of the denitrifying microbes in permeable sediments were unclassified denitrifying microbes, and particle size and heterogeneity were not significantly correlated with the functional gene abundances or denitrification rates. Water chemistry was the key controlling factor for the denitrification of permeable sediments. Water NO3−-N directly regulated the denitrification rate of permeable sediments, instead of indirectly regulating the denitrification rate of sediments by affecting the chemical characteristics of the sediments. Our study fills a knowledge gap of denitrification in permeable sediment in a headwater river and highlights that particle size and heterogeneity are less important for permeable sediment denitrification.
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影响因子：
5.1
作者：
Han, Shun;Luo, Xuesong;Huang, Qiaoyun
通讯作者：
Huang, Qiaoyun
影响因子：
16.6
作者：
Ouyang L;Thamdrup B;Trimmer M
通讯作者：
Trimmer M
有机碳的有效性限制了深渗流区的微生物反硝化
影响因子：
5.1
作者：
Chen, Shuaimin;Wang, Fenghua;Liu, Binbin
通讯作者：
Liu, Binbin
影响因子：
64.8
作者：
KEIL, RG;MONTLUCON, DB;HEDGES, JI
通讯作者：
HEDGES, JI
DOI：
10.1029/jb090ib04p03099
发表时间：
1985-01-01
期刊：
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS
影响因子：
--
作者：
GANGI, AF
通讯作者：
GANGI, AF