Abstract Sinking marine particles drive the biological pump that naturally sequesters carbon from atmosphere. Despite their small size, compartmentalized nature of promotes intense localized metabolic activity by bacterial colonizers. Yet mechanisms promoting onset denitrification, a metabolism arises once oxygen is limiting, remain to be established. Here we show experimentally slow sinking ag...

Simultaneous nitrification and denitrification (SND) under low dissolved oxygen (DO) and anaerobic/aerobic(anoxic) enhanced phosphorus removal (EBPR) are two processes that can significantly reduce the energy and carbon required for nutrient removal. The combination of the two processes is expected to achieve biological nutrient removal with minimal requirement of oxygen and carbon. In this stu...

The transport and deposition of anthropogenic nitrogen (N) to downwind ecosystems is significant and can be a dominant source of new N to many watersheds. Bacterially mediated denitrification in lake sediments may ameliorate the effects of N loading by permanently removing such inputs. We measured denitrification in sediments collected from lakes in the Colorado Rocky Mountains (USA) receiving ...

UNLABELLED A major percentage (20 to 40%) of global marine fixed-nitrogen loss occurs in oxygen minimum zones (OMZs). Concentrations of O2 and the sensitivity of the anaerobic N2-producing processes of anammox and denitrification determine where this loss occurs. We studied experimentally how O2 at nanomolar levels affects anammox and denitrification rates and the transcription of nitrogen cycl...

The distribution of denitrification was investigated in the hypolimnion of the east and west lobes of permanently ice-covered Lake Bonney, Taylor Valley, Antarctica. Anomalously high concentrations of dissolved inorganic nitrogen (DIN; nitrate, nitrite, ammonium and nitrous oxide) in the oxygen-depleted hypolimnion of the east lobe of the Lake implied that denitrification is or was active in th...

The rpoN region of Pseudomonas stutzeri was cloned, and an rpoN null mutant was constructed. RpoN was not essential for denitrification in this bacterium but affected the expression levels and enzymatic activities of cytochrome cd1 nitrite reductase and nitric oxide reductase, whereas those of respiratory nitrate reductase and nitrous oxide reductase were comparable to wild-type levels. Since t...

The ability of Neisseria meningitidis to utilize both oxygen and nitrogen oxides as respiratory substrates allows it to thrive in the diverse environment of the human host. Genome analysis highlighted genes encoding a cbb(3) cytochrome oxidase, the aniA nitrite reductase gene and the norB nitric oxide reductase gene. In the present study, we used myxothiazol as an inhibitor of the bc(1) complex...

The estuarine nitrogen cycle can be substantially altered due to anthropogenic activities resulting in increased amounts of inorganic nitrogen (mainly nitrate). In the past, denitrification was considered to be the main ecosystem process removing reactive nitrogen from the estuarine ecosystem. However, recent reports on the contribution of dissimilatory nitrate reduction to ammonium (DNRA) to n...

Pseudomonas aeruginosa is a metabolically flexible member of the Gammaproteobacteria. Under anaerobic conditions and the presence of nitrate, P. aeruginosa can perform (complete) denitrification, a respiratory process of dissimilatory nitrate reduction to nitrogen gas via nitrite (NO2), nitric oxide (NO) and nitrous oxide (N2O). This study focuses on understanding the influence of environmental...

We have shown that many fungi (eukaryotes) exhibit distinct denitrifying activities, although occurrence of denitrification was previously thought to be restricted to bacteria (prokaryotes), and have characterized the fungal denitrification system. It comprises NirK (copper-containing nitrite reductase) and P450nor (a cytochrome P450 nitric oxide (NO) reductase (Nor)) to reduce nitrite to nitro...