Anaerobic ammonium oxidation in the Peruvian oxygen minimum zone
Anaerobic ammonium oxidation in the Peruvian oxygen minimum zone
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DOI：
10.4319/lo.2007.52.3.0923
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发表时间：
2007-05-01
影响因子：
4.5
通讯作者：
Kuypers, Marcel M. M.
中科院分区：
文献类型：
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作者：
Hamersley, M. Robert;Lavik, Gaute;Kuypers, Marcel M. M.
我们利用 N-15 标记底物的短时间厌氧培养以及分子生态学和脂质生物标志物研究，研究了 2005 年 4 月穿过南纬 12 度秘鲁最低氧区 (OMZ) 的一条横断面中氮 (N) 损失的微生物途径。在与 (NH4+)-N-15 一起孵育时，立即产生 (NN)-N-14-N-15，但不产生 (NN)-N-15-N-15，这表明 N-2 是通过厌氧氨氧化 (anammox) 将标记的 (NH4+)-N-15 与原位 (NO2-)-N-14 配对产生的。支持这一发现的是，我们还发现了与厌氧氨氧化相关的 16S 核糖体核糖核酸基因序列，与之前从测量厌氧氨氧化活性的其他海水柱中已知的序列相似。我们通过荧光原位杂交和定量聚合酶链反应鉴定和计数了厌氧氨氧化细菌，并在通过同位素示踪方法测量厌氧氨氧化活性的任何地方发现了厌氧氨氧化细菌特有的梯烷膜脂。然而，在与 (NO3-)-N-15 或 (NO2-)-N-15 一起孵育时，预计反硝化作用会通过氧化的 N-15 离子配对产生 (NN)-N-15-N-15，但在 24 小时之前未检测到 (NN)-N-15-N-15 的产生，这表明我们的样品中并未发生固定 N 反硝化为 N-2 的情况。在我们研究的时间和地点，秘鲁 OMZ 水域中 N-2 的产生是由厌氧氨氧化而不是反硝化作用造成的。
We investigated the microbial pathways of nitrogen (N) loss in an April 2005 transect through the Peruvian oxygen minimum zone (OMZ) at 12 degrees S latitude using short anaerobic incubations with N-15-labeled substrates and molecular-ecological and lipid-biomarker studies. In incubations with (NH4+)-N-15, immediate production of (NN)-N-14-N-15, but not (NN)-N-15-N-15, indicated that N-2 was produced by the pairing of labeled (NH4+)-N-15 with in situ (NO2-)-N-14 via anaerobic ammonium oxidation (anammox). Supporting this finding, we also found anammox-related 16S ribosomal ribonucleic acid gene sequences similar to those previously known from other marine water columns in which anammox activity was measured. We identified and enumerated anammox bacteria via fluorescence in situ hybridization and quantitative polymerase chain reaction and found ladderane membrane lipids specific to anammox bacteria wherever anammox activity was measured by our isotope tracer method. However, in incubations with (NO3-)-N-15 or (NO2-)-N-15, in which denitrification would have been expected to produce (NN)-N-15-N-15 by pairing of oxidized N-15 ions, (NN)-N-15-N-15 production was not detected before 24 h, showing that denitrification of fixed N to N-2 was not taking place in our samples. At the time and locality of our study, anammox, rather than denitrification, was responsible for N-2 production in the Peruvian OMZ waters.