Anaerobic ammonium oxidation in an estuarine sediment
Anaerobic ammonium oxidation in an estuarine sediment
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DOI：
10.3354/ame036293
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发表时间：
2004-09-14
影响因子：
1.4
通讯作者：
Revsbech, NP
中科院分区：
文献类型：
--
作者：
Risgaard-Petersen, N;Meyer, RL;Revsbech, NP
在丹麦兰德斯峡湾和诺斯明德峡湾这两个浅水河口的光合活性沉积物中研究了与反硝化相关的厌氧氨氧化（厌氧氨氧化）过程的发生和意义。厌氧氨氧化占兰德斯峡湾沉积物中 N-2 产量的 5% 至 24%，而在诺斯明德峡湾的沉积物中没有发现这一过程的迹象。这表明，兰德斯峡湾中存在厌氧氨氧化而诺斯明德峡湾中不存在厌氧氨氧化，与沉积物低氧区中 NO3- + NO2- (NOx-) 的可用性差异有关。在兰讷斯峡湾，NOx- 全年存在于水体中，NOx- 孔隙水剖面显示 NOx- 渗透到沉积物的低氧区。在诺斯明德峡湾，夏季水柱中不存在氮氧化物，通过同化作用，底栖微藻可以阻止氮氧化物渗透到沉积物的低氧区。兰德斯峡湾的特定体积厌氧氨氧化率与其他研究人员之前在斯卡格拉克沉积物中测量的率相当，但反硝化率高出 10 至 15 倍。因此，与斯卡格拉克沉积物相比，厌氧氨氧化对兰德斯峡湾 N-2 生产的贡献较小。我们认为，兰德斯峡湾厌氧氨氧化的贡献较低与易于获取的碳的可用性较高有关，而碳可支持更多的反硝化细菌种群。使用浮霉菌特异性引物对从兰德斯峡湾沉积物样本中提取的 DNA 进行扩增，得到了与其他研究人员在黑海发现的 Candidatus Scalindua sorokinii 密切相关的 16S rRNA 基因序列。因此，本研究证实了与candidatus S. sorokinii相关的细菌的存在与海洋环境中的厌氧氨氧化反应之间的联系。使用 N-15 和微传感器技术估算了具有完整化学梯度的沉积物中的厌氧氨氧化率。使用微传感器估算的厌氧氨氧化率低于使用同位素测量的厌氧氨氧化率的 22%。有人认为这种差异是由于动物群的存在造成的，因为所应用的 N-15 技术捕获总 N-2 产量，而微传感器技术仅捕获沉积物表面扩散控制的 N-2 产量。当应用于动物区系丧失的沉积物时，这些方法之间的一致一致性证实了这一假设。
The occurrence and significance of the anammox (anaerobic ammonium oxidation) process relative to denitrification was studied in photosynthetically active sediment from 2 shallow-water estuaries: Randers Fjord and Norsminde Fjord, Denmark. Anammox accounted for 5 to 24 % of N-2 production in Randers Fjord sediment, whereas no indication was seen of the process in sediment from Norsminde Fjord, It is suggested that the presence of anammox in Randers Fjord and its absence from Norsminde Fjord is associated with differences in the availability of NO3- + NO2- (NOx-) in the suboxic zone of the sediment. In Randers Fjord, NOx- is present in the water column throughout the year and NOx- porewater profiles showed that NOx- penetrates into the suboxic zone of the sediment. In Norsminde Fjord, NOx- is absent from the water column during the summer months and, via assimilation, benthic microalgae may prevent penetration of NOx- into the suboxic zone of the sediment. Volume-specific anammox rates in Randers Fjord were comparable with rates measured previously in Skagerrak sediment by other investigators, but denitrification rates were 10 to 15 times higher. Thus, anammox contributes less to N-2, production in Randers Fjord than in Skagerrak sediment, We propose that the lower contribution of anammox in Randers Fjord is linked to the higher availability of easily accessible carbon, which supports a higher population of denitrifying bacteria. Amplification of DNA extracted from the sediment samples from Randers Fjord using planctomycete-specific primers yielded 16S rRNA gene sequences closely related to candidatus Scalindua sorokinii found in the Black Sea by other investigators. The present study thus confirms the link between the presence of bacteria affiliated with candidatus S. sorokinii and the anammox reaction in marine environments. Anammox rates in sediment with intact chemical gradients were estimated using both N-15 and microsensor techniques. Anammox rates estimated with microsensors were less than 22 % of the rates measured with isotopes. It is suggested that this discrepancy was due to the presence of fauna, because the applied N-15 technique captures total N-2 production while the microsensor technique only captures diffusion-controlled N-2 production at the sediment surface. This hypothesis was verified by consistent agreement between the methods when applied to defaunated sediments.