Nitrospira

[Meyer Jordan]

Meyer Jordan submitted a new article:

Nitrospira - The paradigm shift continues.

In an earlier posted article, Archaea The not-so-new-kids-on-the-block, we briefly discussed the emergence of certain species of the Domain Archaea as the prime ammonia oxidizing organisms in both terrestrial and aquatic environments world-wide.

Over the past several years there has been increasing evidence that a similar altering of perceived role dominance is extant in Nitrite oxidation.

Some bacterial and archaeal species defy replication under lab condition and have also defied easy...

Read more about this article...

 

[MitchM]

What is the ammonia ppm level range between "raised ammonia levels and reduced ammonia levels"?

 

[Meyer Jordan]

What is the ammonia ppm level range between "raised ammonia levels and reduced ammonia levels"?

Without going into great technical detail, here is briefly what research has found-
-Free ammonia inhibition on respiration in Nitrobacter initiated at below 1 mg/L NH3.
-Respiration gradually decreased by 12% when free ammonia concentration increased from 0 to 4 mg/L NH3.
-Nitrobacter ceased to grow at a free ammonia level above 6 mg/L NH3.

 

[MitchM]

It's my understanding that using too much ammonia during a fishless cycling process will delay the process due to lack of oxygen.
With the presence of archaea and nitrospira, does that mean that my understanding is wrong?

 

[Meyer Jordan]

It's my understanding that using too much ammonia during a fishless cycling process will delay the process due to lack of oxygen.
With the presence of archaea and nitrospira, does that mean that my understanding is wrong?

I can not remember ever seeing any reference to Ammonia levels affecting DO levels. Ammonia does inhibit Oxygen transfer at the gill surface of fish.
Assuming DO levels of >3.0 mg/L, I would think that the use of too much Ammonia during fishless cycling would surely delay the process, but not due to any inhibition of Oxygen, but rather lack of sufficient bacteria/archaea colony size which, in turn, has been limited by available SSA. Fewer bacteria/archaea will most certainly take longer to process larger Ammonia levels.

 

[MitchM]

I don't think that it was the ammonia level that was responsible for the reduced DO, but the extra nitrosomonas activity that consumed O2 to a point that it delayed the next step of nitrite oxidiation by nitrobacter that was the issue.
I have never been able to find how far the O2 was supposedly depleted, or how that would have really affected the cycle.
Thanks.

 

[Meyer Jordan]

Increased bacterial activity does consume more Oxygen and can lead to lower DO levels especially at higher temperatures. I guess it could happen, but I find it hard to imagine DO levels being reduced that much in a fishless pond. I would be interested in reading the document related to this if you still have a link.

 

[MitchM]

That's the problem, I haven't been able to find a study to demonstrate that.
I first heard of the possible issue from a past member here, Waterbug.
He was very knowledgeable and I respect his opinion. He wasn't certain of it either, but I thought the concept was legitimate.
Given that archaea and nitrospira can survive in an O2 depleted enviroment, maybe it's a non-issue.

 

[Meyer Jordan]

I just can't visualize a scenario in a fishless garden pond where the BOD would ever exceed the natural rate of Oxygen replenishment. In larger eutrophic bodies of water where stratification occurs this is often a recurring problem. Maybe that is what Waterbug was thinking of.

Nitrospira and archaea survive anoxic conditions but all oxidation processes are reduced.

 

[MitchM]

So as far as fishless cycling goes, we are still at a point where the recommended ammonia level should be followed, 3 ppm, but if the level is above that, there should not be any delay in the establishment of a healthy biofilm that can support a fish population.

 

[Meyer Jordan]

So as far as fishless cycling goes, we are still at a point where the recommended ammonia level should be followed, 3 ppm, but if the level is above that, there should not be any delay in the establishment of a healthy biofilm that can support a fish population.

Providing that there is sufficient SSA to support the required additonal colony growth. Same principle as having a bio-filter large enough (SSA) to sustain a pond with fish.

Question. Who established 3 ppm as the recommended level?

 

[MitchM]

I can't find any specific information on the 3 ppm either, just seems to be a "recommended" level.

 

[Meyer Jordan]

I have seen 2 ppm mentioned and also 4 ppm mentioned. It may be related more to the fact that increasing Ammonia levels progressively restrict the oxidizing processes of Nitrobacter with all processes ceasing at 6 ppm Ammonia.
I seem to remember seeing use of the phrase "stall the cycling process" used in relation to Ammonia levels, so I guess 2 - 4 ppm was settled on as a workable level.

 

[Meyer Jordan]

A good reference chart-

 

[MitchM]

Just to be clear, "ammonia nitrogen" is not something new to be measuring for, it's just another way of saying regular ammonia.