Correlation between Anammox Activity and Microscale Distribution of Nitrite in a Subtropical Mangrove Sediment

Abstract

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 ؊ (NO 2 ؊ plus NO 3 ؊ ) and NO 2 ؊were measured with microscale biosensors, and the availability of NO 2 ؊ 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 NO 2 ؊ as a substrate, also provides a substrate for the anammox process, which has been suggested in previous studies where microscale NO 2 ؊ profiles were not measured.

Dissimilatory reduction of nitrate to ammonium, not denitrification or anammox, dominates benthic nitrate reduction in tropical estuaries

“…Meyer et al (2005) reported AN from a subtropical sediment, correlated with benthic nitrite distribution. Nicholls and Trimmer (2009) have argued that the importance of AN potential increases with both organic carbon content of sediment and with nitrate concentration in the overlying water, and that there is increase of AN relative to DN at lower temperature (Dalsgaard and Thamdrup 2002;Rysgaard et al 2004) .…”

Presence and activity of anaerobic ammonium-oxidizing bacteria at deep-sea hydrothermal vents

“…Our future effort will focus on the enrichment of the members of this cluster in a laboratory scale bioreactor. Anammox metabolism in marine ecosystems was an important discovery for the oceanic nitrogen cycle (Dalsgaard et al, 2003;Kuypers et al, 2003;Meyer et al, 2005); anammox bacteria highlighted in hydrothermal ecosystems could allow a better comprehension of the nitrogen cycle in the deep ocean.…”

Production of nitrogen gas via anammox and denitrification in intact sediment cores along a continental shelf to slope transect in the North Atlantic

“…The potential for anammox has now been reported for sediments from estuaries (Trimmer et al 2003;RisgaardPetersen et al 2004;Meyer et al 2005) and coastal seas Thamdrup and Dalsgaard 2002;Rysgaard et al 2004) and, in addition, several anoxic bodies of water Kuypers et al 2003Kuypers et al , 2005. The contribution of anammox to N 2 production has been found to be very high in some sediments, accounting for up to 80% of N removal (Engströ m et al 2005).…”

“…The precise regulation of anammox in sediments is, as yet, unclear, though the current dogma is that denitrification decreases relative to anammox with increasing water depth offshore because of the associated decrease in availability of organic carbon needed to drive sediment mineralization and, thus, denitrification Dalsgaard et al 2005;Engströ m et al 2005). In addition, anammox may be favored in colder regions and-or those systems where NO { 3 and its reduction to NO { 2 are both high and consistent Meyer et al 2005;Trimmer et al 2005). Despite this progress the majority of studies on anammox and denitrification in sediment are potentials based on anaerobic slurry incubations.…”