Source of ammonia oxidising enzymes

[GrahamC]

There's an article on PLOS which reports new research from Canada where the laboratory there looked at both freshwater and marine aquaria to see what were the main sources of ammonia oxidation. In the cycled fresh water tanks they found no bacteria at all using PCR probes, and the source for the ammonia oxidizing enzymes were in fact archaea. In their small sample of marine tanks, the populations were more 50:50 with archaea, and nitrifying bacteria occupying the same tank. So, more things to consider when looking at the nitrogen cycle in tanks and trouble shooting thereof.

They didn't look at the cycling process itself. So, it is possible that in the first weeks of a tank, the ammonia gets processed by the nitrifying bacteria as we always have been told, but as the tank ages, archaea move in replacing the bacteria. And that raises the question as to whether a fishless cycle results in two different microbial populations as high ammonia levels favour the growth nitrifying bacteria, whereas archaea are found more at low ammonia levels. Archaea also feed on microbial life forms so possibly may have to wait for fish to populate the tank first.

[alanmin4304]

I don't suppose it really matters what it is so long as it is in there chomping away at the ammonia and nitrite.

[GrahamC]

It does have some practical implications.

Nitrifying bacteria are gram negative, and people have always wondered why antibiotics active against gram negatives don't disturb the bacterial filter, but antibiotics active against gram positive bacteria do. It may be that archaea are sensitive to the latter.

In the two bacterial supplements they tested, they found lots of nitrifying bacterial DNA but no Archaea DNA or rRNA. So, maybe these companies need to see if they can incorporate Archaea also into their potions.

[Cricketman]

link?

http://en.wikipedia.org/wiki/Archaea

Bit of info about Archaea for those who want to know what were talking about.

[blueether]

Looks to this http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0023281

[livingart]

so you are better to cycle with a few fish and water changes then

[GrahamC]

Well, you can do a fishless cycle it seems and get nitrifying bacteria that way, but ultimately in a freshwater aquarium it now seems we want archaea and not bacteria. I wonder if adding some infusoria to the ammonia in a fishless cycle might work and encourage archaea to multiply.

[blueether]

If I read it right they are the same archaea found in stream beds/silt, so that could be a easy way to start a filter off*, if you don't mind the potential for introducing algae

*Saying that the tank that my WCMM are in in was started with sand and silt substrate (silt was on Elatine gratioloides), never saw an ammonia spike.

[GrahamC]

*Saying that the tank that my WCMM are in in was started with sand and silt substrate (silt was on Elatine gratioloides), never saw an ammonia spike.

Interesting. I might try that the next time I drive by a fresh water stream.

[blueether]

Interesting. I might try that the next time I drive by a fresh water stream.

There is not a huge bio-load in the tank, there is probably a higher load from the snails.

If I can convince SWMBO to let me get another 4' or better a 6' tank I'll give it a go with a bigger bio-load