Marlene Mark Jensen

TL;DR: It is shown that in the ETSP-OMZ, anammox obtains 67% or more of NO2− from nitrate reduction, and 33% or less from aerobic ammonia oxidation, based on stable-isotope pairing experiments corroborated by functional gene expression analyses.

TL;DR: Because anammox is a major nitrogen loss in marine suboxic waters, such nitrification–anammox coupling potentially occurring also in oceanic oxygen minimum zones would act as a short circuit connecting regenerated ammonium to direct nitrogen loss, thus reducing the presumed direct contribution from deep-sea nitrate.

TL;DR: In this paper, the pathways of N2 production in the oxygen-deficient water column of the eastern tropical South Pacific off Iquique, Chile, at 20uS, through short anoxic incubations with 15N-labeled nitrogen compounds were investigated.

TL;DR: Comparing nitrite oxidation rates with those of nitrate reduction to nitrite, ammonia oxidation, anammox, denitrification, as well as dissimilatory nitrate/nitrite reduction to ammonium in the Namibian oxygen minimum zone reveals that a considerable fraction of the recently recycled nitrogen or reducedNO3− was re-oxidized back to NO3− via nitrite oxidization, instead of being lost from the system through the anamm Oxidization or denit

TL;DR: This study provides the first robust estimates of O2 sensitivities for processes directly and indirectly connected with N-loss, and shows that aerobic and anaerobic N-cycle pathways in OMZs can co-occur over a larger range of O1 concentrations than previously assumed.