Community Structures and Distribution of Anaerobic Ammonium Oxidizing and nirS-Encoding Nitrite-Reducing Bacteria in Surface Sediments of the South China Sea
Community Structures and Distribution of Anaerobic Ammonium Oxidizing and nirS-Encoding Nitrite-Reducing Bacteria in Surface Sediments of the South China Sea
复制标题
南海表层沉积物中厌氧氨氧化和nirS编码亚硝酸盐还原菌的群落结构和分布
DOI：
10.1007/s00248-012-0175-y
复制
发表时间：
2013-08-01
影响因子：
3.6
通讯作者：
Gu, Ji-Dong
中科院分区：
文献类型：
--
作者：
Li, Meng;Hong, Yiguo;Gu, Ji-Dong
厌氧氨氧化（anammox）和反硝化是造成氮损失的两个重要过程；对执行这两个过程的微生物群落进行监测为了解微生物氮循环提供了独特的机会。本研究的目的是表征南海北部（SCS）表层沉积物中厌氧氨氧化菌和编码亚硝酸盐还原菌的群落结构和分布。厌氧氨氧化细菌的三个生物标志物（包括16S rRNA、hzo和Scalindua-nirS基因）的一致系统发育结果表明，类Scalindua细菌是南海表层沉积物中唯一存在的厌氧氨氧化菌群。然而，在该类群中发现了相对较高的微观多样性，包括几种南海生境特有的系统型，Candidatus“Scalindua zhenghei”。与16S rRNA基因相比，hzo和Scalindua-nirS基因为阐明厌氧氨氧化细菌提供了相对更高的分辨率。对于编码nirS的亚硝酸盐还原菌，检测到的nirS基因序列与各种海洋nirS反硝化细菌密切相关，特别是那些起源于沿海和河口沉积物的反硝化细菌，其多样性比厌氧氨氧化细菌高得多。 Anammox 细菌群落随着海水深度而变化，而编码 nirS 的亚硝酸盐还原细菌却没有。尽管编码 nirS 的亚硝酸盐还原菌比厌氧氨氧化菌具有更高的丰度和多样性，但它们在研究地点表现出相似的丰度变化模式，表明这两个微生物群可能受到相似环境因素的影响。两个微生物群的丰度与沉积物中NH4+与(NO2− + NO3−)的摩尔比、pH和有机质之间的显着相关性有力地支持了这一假设。
Anaerobic ammonium oxidation (anammox) and denitrification are two important processes responsible for nitrogen loss; monitoring of microbial communities carrying out these two processes offers a unique opportunity to understand the microbial nitrogen cycle. The aim of the current study was to characterize community structures and distribution of anammox and nirS-encoding nitrite-reducing bacteria in surface sediments of the northern South China Sea (SCS). The consistent phylogenetic results of three biomarkers of anammox bacteria, including 16S rRNA, hzo, and Scalindua-nirS genes, showed that Scalindua-like bacteria were the only anammox group presenting in surface sediments of the SCS. However, a relatively high micro-diversity was found within this group, including several SCS habitat-specific phylotypes, Candidatus “Scalindua zhenghei”. Comparing to 16S rRNA gene, hzo and Scalindua-nirS genes provided a relatively higher resolution to elucidate anammox bacteria. For the nirS-encoding nitrite-reducing bacteria, the detected nirS gene sequences were closely related to various marine nirS denitrifiers, especially those which originated from coastal and estuarine sediments with a much higher diversity than anammox bacteria. Anammox bacterial communities shifted along with the seawater depth, while nirS-encoding nitrite-reducing bacteria did not. Although nirS-encoding nitrite-reducing bacteria have a much higher abundance and diversity than anammox bacteria, they showed similar abundance variation patterns in research sites, suggesting the two microbial groups might be affected by the similar environmental factors. The significant correlations among the abundance of the two microbial groups with the molar ratio of NH4+ to (NO2− + NO3−), pH, and organic matters of sediments strongly supported this hypothesis.