Amazing stuff! What little we still know about our planet!
"A previously unknown biological pathway allows a widespread type of oceanic archaeon to release both oxygen and nitrogen in the dark – the first time such a phenomenon has been seen in nature in an anoxic environment. The process, whose details are not yet fully understood, could transform scientists’ understanding of the cycle of key nutrients in oceans. Ammonia-oxidising archaea are among the most abundant microbes in the world’s oceans. They obtain energy by using oxygen to oxidise ammonia to nitrite. ..."
From the abstract:
"... Nevertheless, AOA [Ammonia-oxidizing archaea] are abundant in environments where oxygen is undetectable. By carrying out incubations for which oxygen concentrations were resolved to the nanomolar range, we show that after oxygen depletion, Nitrosopumilus maritimus produces dinitrogen and oxygen, which is used for ammonia oxidation. The pathway is not completely resolved but likely has nitric oxide and nitrous oxide as key intermediates. N. maritimus joins a handful of organisms known to produce oxygen in the dark. ..."
Oxygen and nitrogen production by an ammonia-oxidizing archaeon (no public access)
llustration of the role of ammonia-oxidising archaea (AOA) and nitrite-oxidising bacteria (Nob) in the marine nitrogen cycle inside oxygen minimum zones. Nitrification occurs below the zone where sunlight can penetrate the oceanic water column. But thus far, it was believed not to be possible in anoxic zones
No comments:
Post a Comment