Meyer Rikke Louise, Risgaard-Petersen Nils, Allen Diane Elizabeth
Advanced Wastewater Management Centre, The University of Queensland, St. Lucia, QLD 4072, Australia.
Appl Environ Microbiol. 2005 Oct;71(10):6142-9. doi: 10.1128/AEM.71.10.6142-6149.2005.
The distribution of anaerobic ammonium oxidation (anammox) in nature has been addressed by only a few environmental studies, and our understanding of how anammox bacteria compete for substrates in natural environments is therefore limited. In this study, we measure the potential anammox rates in sediment from four locations in a subtropical tidal river system. Porewater profiles of NO(x)(-) (NO2- plus NO3-) and NO2- were measured with microscale biosensors, and the availability of NO2- was compared with the potential for anammox activity. The potential rate of anammox increased with increasing distance from the mouth of the river and correlated strongly with the production of nitrite in the sediment and with the average concentration or total pool of nitrite in the suboxic sediment layer. Nitrite accumulated both from nitrification and from NO(x)(-) reduction, though NO(x)(-) reduction was shown to have the greatest impact on the availability of nitrite in the suboxic sediment layer. This finding suggests that denitrification, though using NO2- as a substrate, also provides a substrate for the anammox process, which has been suggested in previous studies where microscale NO2- profiles were not measured.
自然界中厌氧氨氧化（anammox）的分布仅在少数环境研究中有所涉及，因此我们对anammox细菌在自然环境中如何竞争底物的了解有限。在本研究中，我们测量了亚热带潮汐河系四个地点沉积物中的潜在anammox速率。使用微型生物传感器测量了NO(x)(-)（NO2-加NO3-）和NO2-的孔隙水剖面，并将NO2-的可用性与anammox活性的潜力进行了比较。anammox的潜在速率随着离河口距离的增加而增加，并且与沉积物中亚硝酸盐的产生以及亚oxic沉积物层中亚硝酸盐的平均浓度或总量密切相关。亚硝酸盐既来自硝化作用，也来自NO(x)(-)的还原，尽管NO(x)(-)的还原对亚oxic沉积物层中亚硝酸盐的可用性影响最大。这一发现表明，反硝化作用虽然以NO2-为底物，但也为anammox过程提供了底物，这在以前未测量微型NO2-剖面的研究中已有暗示。
