Fig. 4: Microbial mechanisms of NO production and the proposed impact of nitrate-reducing Fe(II) oxidation on BIF formation.
From: Inhibition of phototrophic iron oxidation by nitric oxide in ferruginous environments
a,b, Schematics demonstrating the variety of pathways in the nitrogen cycle that can lead to production of toxic NO (a) and the potential marginalization of photoferrotrophs by nitrate-reducing Fe(II) oxidizers in an early stratified continental shelf with cyanobacteria beginning to colonize benthic mats, produce O2 and enhance the availability of NO3− (b). The vertical scale of the shelf is exaggerated. DNRA, dissimilatory nitrate reduction to ammonium; anammox, anaerobic ammonium oxidation; Feammox, anaerobic ammonium oxidation coupled with Fe(III) reduction; NR FeOx, nitrate-reducing Fe(II)-oxidizing microorganisms.
