Diversity of ammonia-oxidizing archaea and bacteria in the sediments of a hypernutrified subtropical estuary: Bahia del Tobari, Mexico
Diversity of ammonia-oxidizing archaea and bacteria in the sediments of a hypernutrified subtropical estuary: Bahia del Tobari, Mexico
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DOI：
10.1128/aem.00946-06
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发表时间：
2006-12-01
影响因子：
4.4
通讯作者：
Francis, Christopher A.
中科院分区：
文献类型：
--
作者：
Beman, J. Michael;Francis, Christopher A.
河口沉积物中的硝化作用在全球尺度和单个河口的氮循环中起着重要的作用。虽然细菌曾经被认为是唯一负责催化这一过程的第一步和限速步骤，但最近的几项研究表明，嗜温Crenarchaeota能够进行氨氧化。在这里，我们研究氨氧化古菌（AOA）和细菌（AOB）沉积物内的巴伊亚德尔托巴里，一个富营养化的河口接收大量的铵在农业径流的多样性（丰富度和社区组成）。使用PCR引物设计，专门针对古细菌氨单加氧酶α-亚基（amoA）基因，我们发现AOA是存在于五个采样点在这个河口，并在两个采样时间点（2004年1月和10月）。相比之下，细菌amoA基因仅在40%的样本中可通过PCR扩增。细菌amoA库占主导地位的几个广泛分布的亚硝化单胞菌样序列类型，而AOA多样性表现出显着的变化，在丰富度和社区组成。AOA社区，但表现出一致的空间结构，两个不同的端员组合从内部和河口和混合组合从中间站点恢复。这些研究结果代表了河口沉积物中的古菌amoA多样性的第一次详细检查，并表明，不同的社区Crenarchaeota能够氨氧化存在于河口，在那里他们可能积极参与硝化作用。
Nitrification within estuarine sediments plays an important role in the nitrogen cycle, both at the global scale and in individual estuaries. Although bacteria were once thought to be solely responsible for catalyzing the first and rate-limiting step of this process, several recent studies have suggested that mesophilic Crenarchaeota are capable of performing ammonia oxidation. Here we examine the diversity (richness and community composition) of ammonia-oxidizing archaea (AOA) and bacteria (AOB) within sediments of Bahia del Tobari, a hypernutrified estuary receiving substantial amounts of ammonium in agricultural runoff. Using PCR primers designed to specifically target the archaeal ammonia monooxygenase a-subunit (amoA) gene, we found AOA to be present at five sampling sites within this estuary and at two sampling time points (January and October 2004). In contrast, the bacterial amoA gene was PCR amplifiable from only 40% of samples. Bacterial amoA libraries were dominated by a few widely distributed Nitrosomonas-like sequence types, whereas AOA diversity showed significant variation in both richness and community composition. AOA communities nevertheless exhibited consistent spatial structuring, with two distinct end member assemblages recovered from the interior and the mouths of the estuary and a mixed assemblage from an intermediate site. These findings represent the first detailed examination of archaeal amoA diversity in estuarine sediments and demonstrate that diverse communities of Crenarchaeota capable of ammonia oxidation are present within estuaries, where they may be actively involved in nitrification.