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Old 01-02-2014, 01:46 AM   #191
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Source: http://www.isws.illinois.edu/pubdoc/CR/ISWSCR-326.pdf
Early 80's I am guessing simply based on the age of the citations.

The effects of toxins on Nitrobacter can be detected easily by monitoring changes in their nitrite consumption rate.
Inorganic ions and organic compounds were tested. Cadmium, copper, lead, nickel, phenol, clorophenol, dichlorophenol, and trichlorophenol

Trichlorophenol was the most toxic organic. with median concentraions of 2.6-4.7 mg/l. Among inorganics, cadmium was most toxic at 40-50mg/l.
The tolerance of nitrobacter is very high.

This isn't really related to our current area of study, but I thought it was interesting to find that nitrobacter is not really effected by toxins in the source water. No mention of Nitrospira, of course this paper came out long before Nitrospira became of high interest to the cycle.
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Old 01-02-2014, 01:49 AM   #192
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Source: Limited impact of free ammonia on Nitrobac... [Bioresour Technol. 2010] - PubMed - NCBI 2010
pH changes and ammonia oxidizing bacteria activity are more important factors limiting Nitrobacter spp. mediated nitrite oxidation, rather than the free ammonia concentration.

Just another paper, a quite recent one, about how free ammonia does not much inhibit nitrobacter. Nitrospira was not studied.

I'm not sure if this is the correct use of irony, but in a textbook I just read an exerpt that also referenced this paper and actually suggested contacting the author for more information. He is a professor at a university here in the states.
I got excited that I might have a human lead to contact, looked him up - and he passed away less than a month ago! (rest in peace)
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Old 01-02-2014, 02:23 AM   #193
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Source: In Situ Characterization of Nitrospira-Like Nitrite-Oxidizing Bacteria Active in Wastewater Treatment Plants 2001

Nitrospira-like nitrite oxidizers represent K strategists adapted to low nitrite and oxygen concentrations, while Nitrobacter sp., as an r strategist, thrives if nitrite and oxygen are present in higher concentrations”
This implies that Nitrospira thrives in more anoxic environments and at lower nitrites than Nitrobacter (as a note, later comments in the study seem to contradict some of this?)

“While Nitrospira was present in significant amounts in all of the samples analyzed, Nitrobacter cells were detected only in sequencing batch biofilm reactor SBBR 1. Reactor SBBR 1 receives reject water from sludge dewatering, which is particularly rich in ammonia and dissolved salts. Due to the batch performance of the reactor, ammonia, nitrite, and nitrate concentrations vary significantly during an operating cycle . The repeated, pronounced temporal nitrite concentration shifts within SBBR 1 create an ecological niche for nitrite oxidizers adapted to high nitrite concentrations that does not occur in continuously operated bioreactors. This niche is obviously filled by Nitrobacter sp., which, according to Schramm et al. (42), is a putative r strategist for nitrite and oxygen. In contrast, the Nitrospira-like bacteria were postulated to be K strategists that can grow with lower nitrite (and oxygen) concentrations and can thus coexist with Nitrobacter bacteria in SBBR 1”
Nitrospira = constant, low supply of nitrites
Nitrobacter = swells of high nitrites


“no uptake of organic or inorganic carbon sources by Nitrospira-like bacteria was observed in the absence of oxygen. However, combined FISH and microsensor measurements revealed that high numbers of Nitrospira-like bacterial cells can persist in biofilm zones with low oxygen pressure”
Soo I am confused by this because earlier it said that Nitrospira is ok with low oxygen, but now it says it won't eat food if it's low oxygen. Maybe it just meant that it will stay alive at all.

“Pure-culture experiments indicated that N. marina is obligately aerobic (49) while N. moscoviensis can oxidize H2 with nitrate as the electron acceptor and CO2 as the sole carbon source”
Some strains of Nitrospira can make their own oxygen. Just a tidbit.
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Old 01-02-2014, 02:57 AM   #194
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My husband looks over and is like "Are those your notes for your 'thesis'?!? It looks like you are ACTUALLY WRITING A THESIS."

I'm like dude I HAVE a topic for my thesis. Caliban I PMed it to you. I ordered that stuff. The other tests might have to wait a week for me to try that first :P

I have one more paper to read tonight (my brain is goo)
I have even been performing additional google searches trying ANY combination to get info on nitrification being inhibited by high nitrites. I have yet to see any scientific evidence that the nitrite oxidizing bacteria are inhibited by high nitrites - none!! However it may just mean that no one has ever studied it. I hope not because we have to rely on others to do the lab work!!
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Old 01-02-2014, 03:22 AM   #195
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Source: Interpreting Water Analysis Test Results

"In fish, ammonia represents the end-product of protein metabolism and what is important is whether it is present in the un-ionized form as free ammonia, NH3, which is toxic to fish (both freshwater and marine) at >0.03 mg/L (ppm),or in the ionized form, NH4+, in which it is innocuous. The relative concentration of each is pH and temperature dependent. The higher the pH, the more of the NH3 will be present. Ammonia can block oxygen transfer in the gills of fish, thereby causing immediate and long term gill damage. Fish suffering from ammonia poisoning will appear sluggish and come to the surface, as if gasping for air. In marine environments, the safe level of NH4+ is between 0.02 and 0.4.

The USEPA recommends a limit of 0.02 ppm as NH3 in freshwater or marine environments. Total ammonia levels, at this limit, can range from 160 ppm at pH 6 and temperature of 5 degrees C to 0.06 ppm at pH 9 and temperature of 25 degrees C."

This is just a reiteration of what we have been learning about NH3 (free ammonia)
The US Environmental Protection Agency has a limit of .02ppm NH3. But here in aquaria we basically enforce much lower limits...

Serious questions, showing how "green" I am about a fish-in cycle, and bad parameters in general.
a) When fish die to assumed bad ammonia levels, how sure are we that it was the ammonia and not the nitrite?
b) Why is such a low level of TAN acceptable for fish-in cycling when free ammonia at that amount is so low? I still believe low ammonia means a cycle that takes FOREVER. Plus the forum is making people WC every day.
c) How often do we get reports of fish dying where we are 100% certain it is ammonia?
d) How many people actually understand the free ammonia part of the API ammonia reading?

Did you happen to see the thread in this subforum with the betta in the cup? Where the ammonia was off the charts? I mean the free ammonia in that cup can't have been that bad. Everyone was shocked the fish was alive, but I kind of wasn't because of all we have learned...
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Old 01-02-2014, 03:37 AM   #196
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oooooook. Last one for today. shew...
Source: https://ftp.kdis.edu.cn/211-xkkr-13/...bioreactor.pdf
2010


“Several studies have indicated that Nitrobacter And Nitrospira were the prevailing NOB in the environment . Some studies have indicated that
Nitrospira , not Nitrobacter, was the numerically dominant nitrite oxidizer in nitrifying biofilms from wastewater treatment plants and aquaria”
Just a rehash of what we now know.

“Nitrobacter was also observed as a superior competitor when the available
substrate was abundant, while Nitrospira thrived under conditions of nitrite scarcity in lab-scale reactors, biofilm membrane reactor systems, or wastewater treatment plant (WWTP) with temporary or spatially elevated nitrite concentrations “
Remember substrate = food
Problem, I can't find any reference to exactly "how much" nitrite is high food and therefore annoying to the Nitrospira
.. Isn't it weird that a bacteria grows inversely to its food source?


“Models of r and K selection in microbial ecology revealed that Nitrospira
is a K -strategist adapted to low nitrite and oxygen concentrations, while
Nitrobacter is an r -strategist that thrives if nitrite and oxygen are present in higher concentrations “
Another reiteration of what we have read elsewhere.

“there was an inverse trend between the abundance of Nitrospira and Nitrobacter. Correlation coefficients linking shifts in NOB community composition to nitrite concentrations illustrated Nitrospira was significantly
and negatively correlated to nitrite concentrations, while Nitrobacter showed no significant relationship to nitrite concentrations “
?? Why would you be negatively correlated with your food source?

“Nitrospira abundance showed a significantly negative
correlation to DO. However, Nitrobacter populations were significantly and positively correlated to DO. when DO concentrations fell below 1.0 mg L
1 in May 2009, we observed a recovery of Nitrospira concentrations and a decrease in Nitrobacter concentrations”
DO = dissolved oxygen
1.0 would be unsustainable to fish

“results suggest that temperature plays a more powerful role in the determination of NOB abundance than DO. There was a sharp difference in adaptation to temperature and DO concentration between these two genera of nitrite oxidizing bacteria. While substrate concentration was insufficient, low DO and warmer temperatures appeared to favor Nitrospira”
Nitrospira likes it warmer than Nitrobacter.
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Old 01-02-2014, 07:39 AM   #197
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Quote:
Originally Posted by Caliban07 View Post
This is done by multplying concentration by molecular weight.
Molecular weight of ammonia is 17g/mol
1mM = 0.001mol/L
So 17 x 0.001 = 0.017g = 17mg since mg/L = ppm 17mg/L =17ppm of ammonium x 15 = 255ppm ammonium
I looked into this and I agree with your math.
One of those studies was dosing 50mM of ammonia which is... 851ppm.
LOL our aquaria work is child's play!
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Old 01-02-2014, 07:51 AM   #198
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lol... ok...
So on page 19 I had a lot of stuff about the studies on Nitrite inhibiting either the ammonia eaters or the nitrite eaters.
The very lowest number seen was 5mM of Nitrite

Which is 230ppm (NO2 molecular weight 46.0055g/mol)

Basically I don't think there is inhibition at the levels we are talking about, at all.
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Old 01-02-2014, 11:39 AM   #199
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Cripes, I hope there isn't a test on this lol. Have you seen anything else that might stall a cycle at the nitrite stage (apart from phospate)?
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Old 01-02-2014, 01:37 PM   #200
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Quote:
Originally Posted by threnjen View Post
To be honest I think fish-in cycling needs to be at 1ppm ammonia or it will take forever. But I don't think you'll even agree with me, since you want a cycle test with .25
Ok im back at work now so replys may be slower.

My thinking is that it doesnt matter how long a fish in cycle takes. As long as its carried out sensibly you should be able to run a cycle right through to the end without worrying about ammonia. Ive cycled a few tanks this way now and not once did ammonia go above 0.25 TAN.

I added fish a couple of weeks in between to be on the safe side.

what is a cycle? establishing a bacteria colony that can susccessfully reduce toxicity levels of ammonia and nitrite down to 0 before it can do harm to fish. The bacteria will grow.

Now does it matter if the target is 4ppm or 1ppm? what i am starting to think is that if to tanks were set up under the same parameters, temp Ph etc that the lower does would be slightly more efficent. What we are trying to do is establish if high levels of X is inhabitory to bacteria colonies. The lower dose in my opinion should be less likely. However, as we know know, our dosings are childs play lol. even so, i would be inclined to think lower is better.
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