Molecular and biogeochemical evidence for ammonia oxidation by marine Crenarchaeota in the Gulf of California
Molecular and biogeochemical evidence for ammonia oxidation by marine Crenarchaeota in the Gulf of California
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DOI：
10.1038/ismej.2007.118
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发表时间：
2008-04-01
期刊：
影响因子：
11
通讯作者：
Francis, Christopher A.
中科院分区：
文献类型：
--
作者：
Beman, J. Michael;Popp, Brian N.;Francis, Christopher A.
硝化作用在海洋生物地球化学中起着重要作用，但是将该过程与介导其介导的微生物联系起来的努力令人惊讶地受到限制。特别是，氨氧化是硝化的第一个且限制的步骤，但是氨氧化速率和丰富的氨氧化细菌（AOB）很少在串联中测量。氨氧化速率尚未与氨氧化古细胞（AOA）直接量化，尽管越来越多的证据表明海洋crenarchaeota能够氧化氨，并且它们是海洋中最丰富的微生物组之一。在这里，我们通过N-15标记直接量化了氨氧化速率，并通过对加利福尼亚海湾的氨基氧酶亚基A（AMOA）基因的定量PCR分析进行了AOA和AOB丰度。基于上水柱（60 m）和氧最小区域（OMZ; 450 m）的明显不同的古细菌AMOA序列类型，设计了新型的AMOA PCR引物，以特异性地靶向和量化“浅”（A组）和“深”（A组）和“深”。 （B组）进化枝。这些引物随着深度恢复了广泛的可变性。在OMZ中，AOA最丰富，可以将硝化作用与硝化结合在一起。在上水柱中，A组A组具有深度和盆地之间的氮生物地球化学的变化，而AOB的数量相对较少或无法检测到。总体而言，（NH4+） - N-15氧化速率与AOA组A AMOA基因拷贝非常相关（R（2）= 0.90，P
Nitrification plays an important role in marine biogeochemistry, yet efforts to link this process to the microorganisms that mediate it are surprisingly limited. In particular, ammonia oxidation is the first and rate-limiting step of nitrification, yet ammonia oxidation rates and the abundance of ammonia-oxidizing bacteria (AOB) have rarely been measured in tandem. Ammonia oxidation rates have not been directly quantified in conjunction with ammonia-oxidizing archaea (AOA), although mounting evidence indicates that marine Crenarchaeota are capable of ammonia oxidation, and they are among the most abundant microbial groups in the ocean. Here, we have directly quantified ammonia oxidation rates by N-15 labeling, and AOA and AOB abundances by quantitative PCR analysis of ammonia monooxygenase subunit A (amoA) genes, in the Gulf of California. Based on markedly different archaeal amoA sequence types in the upper water column (60 m) and oxygen minimum zone (OMZ; 450 m), novel amoA PCR primers were designed to specifically target and quantify 'shallow' (group A) and 'deep' (group B) clades. These primers recovered extensive variability with depth. Within the OMZ, AOA were most abundant where nitrification may be coupled to denitrification. In the upper water column, group A tracked variations in nitrogen biogeochemistry with depth and between basins, whereas AOB were present in relatively low numbers or undetectable. Overall, (NH4+)-N-15 oxidation rates were remarkably well correlated with AOA group A amoA gene copies (r(2) = 0.90, P