Ubiquity and diversity of ammonia-oxidizing archaea in water columns and sediments of the ocean
Ubiquity and diversity of ammonia-oxidizing archaea in water columns and sediments of the ocean
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DOI：
10.1073/pnas.0506625102
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发表时间：
2005-10-11
影响因子：
11.1
通讯作者：
Oakley, BB
中科院分区：
文献类型：
--
作者：
Francis, CA;Roberts, KJ;Oakley, BB
硝化是氨对亚硝酸盐和硝酸盐的微生物氧化，发生在多种环境中，在全球氮循环中起着核心作用。通过氨基氧酶催化，氧化氨的能力以前被认为仅限于β-和伽马 - 蛋白质中的几组。然而，最近的宏基因组研究揭示了独特的单加氧酶α-亚基（AMOA）基因的存在，这些基因源自未养殖的非生物性crenarchaeota。在这里，我们报告了海洋水柱和沉积物中广泛存在氨氧化古细菌（AOA）的分子证据。使用旨在专门针对古细菌AMOA的PCR引物，我们发现AOA在海洋地区普遍存在，这对于全球氮循环至关重要，包括兴奋区的基础，亚氧化水柱，河口和沿海沉积物。各种各样的AOA社区与这些栖息地中的每一个相关，水柱和沉积物之间几乎没有重叠。在海洋沉积物中，大多数AOA序列都是单个采样位置独有的，而少数序列显然是分布的国际大都会。考虑到海洋中有大量的非生物友善的古细菌，我们的结果表明，AOA在全球氮循环中可能起重要但未识别的作用。
Nitrification, the microbial oxidation of ammonia to nitrite and nitrate, occurs in a wide variety of environments and plays a central role in the global nitrogen cycle. Catalyzed by the enzyme ammonia monooxygenase, the ability to oxidize ammonia was previously thought to be restricted to a few groups within the beta- and gamma-Proteobacteria. However, recent metagenomic studies have revealed the existence of unique ammonia monooxygenase alpha-subunit (amoA) genes derived from uncultivated, nonextremophilic Crenarchaeota. Here, we report molecular evidence for the widespread presence of ammonia-oxidizing archaea (AOA) in marine water columns and sediments. Using PCR primers designed to specifically target archaeal amoA, we find AOA to be pervasive in areas of the ocean that are critical for the global nitrogen cycle, including the base of the euphotic zone, suboxic water columns, and estuarine and coastal sediments. Diverse and distinct AOA communities are associated with each of these habitats, with little overlap between water columns and sediments. Within marine sediments, most AOA sequences are unique to individual sampling locations, whereas a small number of sequences are evidently cosmopolitan in distribution. Considering the abundance of nonextremophilic archaea in the ocean, our results suggest that AOA may play a significant, but previously unrecognized, role in the global nitrogen cycle.