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Diversity, Distribution, And Expression Of Diazotroph Nifh Genes In Oxygen-Deficient Waters Of The Arabian Sea, Amal Jayakumar, Mamoon M. D. Al-Rshadat, Bess B. Ward, Margaret R. Mulholland

OES Faculty Publications

The Arabian Sea oxygen minimum zone (OMZ), the largest suboxic region in the world's oceans, is responsible for up to half of the global mesopelagic fixed nitrogen ( N ) loss from the ocean via denitrification and anammox. Dinitrogen (N₂) fixation is usually attributed to cyanobacteria in the surface ocean. Model prediction and physiological inhibition of N₂ fixation by oxygen, however, suggest that N₂ fixation should be enhanced near the oxygen-deficient zone (ODZ) of the Arabian Sea. N₂ fixation and cyanobacterial nifH genes (the gene encoding dinitrogenase reductase) have been reported in surface waters overlying …