Widespread occurrence of the anammox reaction in estuarine sediments

Nicholls, Joanna C.; Trimmer, Mark

doi:10.3354/ame01285

Cited by 103 publications

(94 citation statements)

References 22 publications

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“…Although AN has been reported from a variety of coastal and estuarine environments Dong et al 2009;Nicholls and Trimmer 2009), our data indicated that AN microorganisms were absent and AN was not a significant process in these tropical estuaries. Meyer et al (2005) reported AN from a subtropical sediment, correlated with benthic nitrite distribution.…”

Section: Discussionmentioning

confidence: 50%

“…The relative importance of DNRA in nitrate reduction has become increasingly evident in a number of environments (An and Gardner 2002;Dong et al 2009;Lam et al 2009). A further recently recognized nitrogen removal process has been anammox (AN;Mü lder et al 1995;Strous et al 1999), which has been shown to be widely distributed in estuarine and coastal sediments (Nicholls and Trimmer 2009). In contrast to temperate regions, the significance of estuarine processing of nutrients in tropical estuaries is poorly understood.…”

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confidence: 99%

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

Dong

Sobey

Smith

et al. 2010

Limnology & Oceanography

214

119

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We measured benthic denitrification (DN) and dissimilatory reduction of nitrate to ammonium (DNRA) using the isotope-pairing technique in three tropical estuaries in Thailand (Mae Klong), Indonesia (Cisadane), and Fiji (Vunidawa-Rewa) during rainy, dry, and intermediate seasons along the salinity gradient of each estuary. DNRA dominated. Anammox (AN) was measured initially but neither AN activity nor AN bacteria-related 16S ribosomal RNA genes were detected in any of the estuaries. DN was either zero or extremely low, driven by water column nitrate and not from benthic nitrification-DN. N 2 O was not formed during DN. N 2 O saturations in estuary water were low, except in the nutrified Indonesian estuary, and tropical estuaries are therefore likely to be only small sources of N 2 O. Benthic nitrate reduction was nitrate limited; when nitrate was enhanced experimentally, DN increased slightly, but DNRA increased proportionately much more. Predominance of DNRA over DN in tropical estuaries may be due both to an energetic advantage (greater standard free energy change, DGu) of nitrate ammonifiers over denitrifiers when competing for limited nitrate, and also to higher affinity for nitrate by the nitrate ammonifiers. At tropical temperatures the three processes occur in the order DNRA . DN . AN. In contrast, temperate estuaries, at lower temperature and higher nitrate concentrations, exhibit proportionately greater levels of AN and DN. The Cisadane estuary became anoxic during the dry season, with high ammonium and sulfide, but no nitrate reduction because of lack of nitrate. Addition of nitrate stimulated high rates of autotrophic DN driven by sulfide, but not DNRA.

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Section: Discussionmentioning

confidence: 50%

mentioning

confidence: 99%

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

Dong

Sobey

Smith

et al. 2010

Limnology & Oceanography

214

119

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“…Although denitrification and nitrification are likely important in the estuary, the high levels of potential N 2 fixation measured in the estuary, compared with denitrification potential and NO x and ammonia fluxes, suggests that the anaerobic oxidation of ammonia (Anammox), shown earlier to contribute between 1% and 11% to the production of N 2 in a range of estuarine sediments (Nicholls and Trimmer, 2009), may occur in the Fitzroy estuary. However, further study is required to resolve the importance of Anammox in the Fitzroy estuary.…”

Section: Discussionmentioning

confidence: 99%

Archaeal ammonia oxidizers and nirS-type denitrifiers dominate sediment nitrifying and denitrifying populations in a subtropical macrotidal estuary

et al. 2009

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Nitrification and denitrification are key steps in nitrogen (N) cycling. The coupling of these processes, which affects the flow of N in ecosystems, requires close interaction of nitrifying and denitrifying microorganisms, both spatially and temporally. The diversity, temporal and spatial variations in the microbial communities affecting these processes was examined, in relation to N cycling, across 12 sites in the Fitzroy river estuary, which is a turbid subtropical estuary in central Queensland. The estuary is a major source of nutrients discharged to the Great Barrier Reef nearshore zone. Measurement of nitrogen fluxes showed an active denitrifying community during all sampling months. Archaeal ammonia monooxygenase (amoA of AOA, functional marker for nitrification) was significantly more abundant than Betaproteobacterial (b-AOB) amoA. Nitrite reductase genes, functional markers for denitrification, were dominated by nirS and not nirK types at all sites during the year. AOA communities were dominated by the soil/sediment cluster of Crenarchaeota, with sequences found in estuarine sediment, marine and terrestrial environments, whereas nirS sequences were significantly more diverse (where operational taxonomic units were defined at both the threshold of 5% and 15% sequence similarity) and were closely related to sequences originating from estuarine sediments. Terminal-restriction fragment length polymorphism (T-RFLP) analysis revealed that AOA population compositions varied spatially along the estuary, whereas nirS populations changed temporally. Statistical analysis of individual T-RF dominance suggested that salinity and C:N were associated with the community succession of AOA, whereas the nirS-type denitrifier communities were related to salinity and chlorophyll-a in the Fitzroy river estuary.

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“…do not specifically quantify DNRA) are likely to overestimate true inorganic-nitrogen removal from the system. The co-occurrence of anammox and DNRA can complicate the calculations as the latter could be providing 15 N-labelled ammonium as a substrate for the former (Nicholls and Trimmer 2009). However, the ambient ammonium pool is so large (average 161 lM) that even the highest rate of DNRA measured (371 nM N h -1 ) only contributed 0.2% to this pool per hour and it is therefore unlikely to have significantly altered our anammox calculations.…”

Section: Discussionmentioning

confidence: 99%

Enhanced hyporheic exchange flow around woody debris does not increase nitrate reduction in a sandy streambed

et al. 2017

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Anthropogenic nitrogen pollution is a critical problem in freshwaters. Although riverbeds are known to attenuate nitrate, it is not known if large woody debris (LWD) can increase this ecosystem service through enhanced hyporheic exchange and streambed residence time. Over a year, we monitored the surface water and pore water chemistry at 200 points along a * 50 m reach of a lowland sandy stream with three natural LWD structures. We directly injected 15 N-nitrate at 108 locations within the top 1.5 m of the streambed to quantify in situ denitrification, anammox and dissimilatory nitrate reduction to ammonia, which, on average, contributed 85, 10 and 5% of total nitrate reduction, respectively. Total nitrate reducing activity ranged from 0 to 16 lM h -1 and was highest in the top 30 cm of the stream bed. Depth, ambient nitrate and water residence time explained 44% of the observed variation in nitrate reduction; fastest rates were associated with slow flow and shallow depths. In autumn, when the river was in spate, nitrate reduction (in situ and laboratory measures) was enhanced around the LWD compared with non-woody areas, but this was not seen in the spring and summer. Overall, there was no significant effect of LWD on nitrate reduction rates in surrounding streambed sediments, but higher pore water nitrate concentrations and shorter residence times, close to LWD, indicated enhanced delivery of surface water into the streambed under high flow. When hyporheic exchange is too strong, overall nitrate reduction is inhibited due to short flow-paths and associated high oxygen concentrations.

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Widespread occurrence of the anammox reaction in estuarine sediments

Cited by 103 publications

References 22 publications

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

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

Archaeal ammonia oxidizers and nirS-type denitrifiers dominate sediment nitrifying and denitrifying populations in a subtropical macrotidal estuary

Enhanced hyporheic exchange flow around woody debris does not increase nitrate reduction in a sandy streambed

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