Nitrogen cycle and the bacteria that drive it

[TheEngineer]

I suppose I've never had a very full grasp on what actually makes each step within the nitrogen cycle work. A recent discussion about Vibrant and the potential for adding additional bacteria from one of the bottled sources has me wondering if I'm missing some critical aspects of understanding this process.

I suppose the first question is, "Are there different bacteria for each stage of the cycle?"

In other words, are there "ammonia bacteria," "nitrite bacteria," and "nitrate bacteria"? If yes, do these bacteria in a bottle products only contain the former and not the latter two?

 

[Brew12]

"Are there different bacteria for each stage of the cycle?"

Yes, there are.

"ammonia bacteria,"

These are the Nitrosomonas bacteria. They consume ammonia and turn it into nitrite.

"nitrite bacteria,"

Nitrobacter bacteria convert the nitrite to nitrate.

"nitrate bacteria"

While the first two are nitrifying bacteria, these are considered denitrifying bacteria and there are plenty of them. The issue is that while Nitrosonomas and Nitrobacter bacteria are aerobic, the denitrifying bacteria require anaerobic conditions to work. They convert NO3 to nitrogen gas in deep sand beds or deep within live rock.

If yes, do these bacteria in a bottle products only contain the former and not the latter two?

Most of them contain all 3 but the focus is on the first two.

There is also a Nitrospira bacteria that converts ammonia directly to nitrate within the same cell structure. These are also found in some bottled bacteria products.

 

[mcarroll]

I'd say the confusion lies with the conflation of "nitrogen cycle" and de-/nitrification.

Not the same or identical – the former contains the later. ;)

I think I'd suggest reading through these:

• Nitrogen cycling in corals: the key to understanding holobiont functioning?
• The response of the scleractinian coral Turbinaria reniformis to thermal stress depends on the nitrogen status of the coral holobiont

(You'll see my comments first, which are hopefully helpful, but click through to the abstract or the PDF to read the original articles.)

And honestly, even W's article on the Nitrogen cycle is really good too...it's just not aquarium-oriented.