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Bacteria Questions

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Bacteria Questions

Post by alexmtl on Sun Sep 08, 2013 10:15 am

Originally posted by Gary of Montreal in Canadian Aquarium Connection - Canada's Fish Community
Bacteria questions (http://www.canadianaquariumconnection.com/forum/showthread.php?t=15590)

GaryofMontreal Aug 21st 2013 05:22 PM

Bacteria questions

We have some people here who know a lot about nitrifying bacteria, so i thought I would float two questions that have always wrinkled my brow.

First: when there is a blackout or filter breakdown, how long does it really take for the bacteria in the filter to die off? Has anyone studied that?

Second: if I take a well functioning biological filter off a hard, alkaline water tank and put it on a soft, acid tank (pH 6 to 6.Cool, what happens in the world of bacterial filtration?

I have no 'crisis' reason for asking - just wondering and noticing the recent postings...

Suprd71 Aug 21st 2013 06:56 PM


I can from personal experience relay that bb will remain viable in a closed canister for at least 21hrs. Big storm in July 06 had power out for that amount of time. Tank was 150g with 2 Rena canisters. After power up and daily parameter checks, I had not lost cycle. I would presume that a sponge filter would survive just as well. Now, an hob that drains itself doesnt last much more than an hour or so, but if you are present to pull the media out and drop in the tank, you have a good chance to get to 12hrs or more. I have swapped filters from my 8.2 African tank with my softer 7-7.2 CA/SA tanks without issue either. I have read that pond keepers and breeders in Florida sometimes have big daily swings, from as low as 5.7 in morn to mid 7's by late afternoon and doesnt seem to cause any ill effects either.

caoder Aug 22nd 2013 07:59 AM


pH swings shouldn't affect as much , but TDS swings may. As with any living creature it would need to balance out its salt concentrations within its own body right?

Alexmtl Aug 22nd 2013 08:37 PM


Hi Gary,
Great question. I bet that there are a lot of people surfing the internet to find the answer to this one. I think the response has answered the question: the bacteria survive for many days. (I promise to return this this later when I have more time to provide your source references.)

In general, the microbiology of nitrification has changed dramatically. Many people still believe that it is a nitrobacter and nitrosomonas thing. It is not as recently demonstrated within the past decade. As well many people are under the belief that this is an aerobic process. In fact, it is both. However the clarify many people misunderstand the difference between oxidation and oxygenation.

1. The bacteria responsible for nitrification is complex and as yet unidentified. Therefore it is uncertain which flora survive and which flourish under low oxygen (I will return to expand on this later). The hardiness and adaptability of the microflora, temperature and the amount of N source will determine which flora will predominate at a certain time. Consider the process fluid, dynamic, and reversible. Therefore the question may be rather, how efficient will your filtration be after a hyperoxygenated or hypooxygenated exposure.

2. Bacteria involved are switch hitters, as they function in several types of envirnoments. Some more effectively in others (sources later).

3. What are you worrying about? If you have over stocked your tank, or if you have too much waste due to lack of filtration / under powered equipment, you will get die off of your livestock let alone your microflora. Practice proper principles and you should not have to worry about a power outage, or better yet, understand the principles of the aquarium ecosystem and rest with peace of mind.

Originally Posted by GaryofMontreal (Post 137222)

Second: if I take a well functioning biological filter off a hard, alkaline water tank and put it on a soft, acid tank (pH 6 to 6.Cool, what happens in the world of bacterial filtration?


I do not think this happens very often in nature where a fish will enter into a hard then soft environment. There are so many buffers in real world systems that this is not a concern in nature.

Nitrification bacteria are really a complex puzzle. It is not as well understood as we thought many years ago. Therefore there are many species that are present that would survive conditions, or perhaps operate less effectively until they acclimate to the new conditions. The population dynamics therefore would shift to favour micro-organisms that facilitate N as a food source under the new conditions.

Bacteria are highly adaptable. The new identification methodology has revealed to scientists that they are more present and more versatile that we think.

Please note that this answer was not sourced from the internet. I will be back later to provide scientific referencing, but I though that Gary should receive some conversation starters on this one. Apologies...

sucker4plecos Aug 23rd 2013 01:18 AM


We had a professor from University of Waterloo speak at our club a couple of times and club members helped him out by giving samples of their filter media. He looked at FW and SW, hard and soft water (even one person who used rainwater..... ask me how I know) and was studying bacteria activity ..... I don't have the paper but here is a quote of what he was working on as we discussed bacteria on our forum... it is interesting in that it isn't actually bacteria that is doing the heavy load of work in our tanks.... it is actually archaea..... and it was also interesting to see the genetics and gene make up of these life forms and to find out that they are actually closer to human physiology than to the bacteria...

However there was that study done by Dr. Josh Neufeld at UW regarding denitrifying organisms in freshwater and marine habitats.

He tested a bunch of the "bio-support"-like substances as well and filter media from freshwater and marine environments because the causative agent for denitrification in freshwater ecosystems were relatively unknown. And if I recall correctly he found that freshwater filters were comprised of organisms primarily archaeal in nature (from the archaea family). Which was surprising due to previous research in marine ecosystems that had found denitrification domains almost exclusively on bacterial as opposed to archaeal organisms. The really interesting point that he brought up (if I recall correctly- it has been a while) was that the "bacteria in a bottle" insta-cycle products were comprised mainly of bacteria not archaea. I would be interested to see if these products perform as well as the naturally occurring archaea in freshwater denitrification. If there is a significant performance difference it may be more beneficial to your aquarium in the long run if you allow the natural archaeal populations to flourish and grow as opposed to adding "bottled bacteria".

Oh, to answer the question, form what I have learned, the bacteria will start to die off after 2 or 3 days... depending on how it is being kept, some will survive because any of the dying material will add ammonia for some of the other to feed on and it will keep itself alive for a while but in a downward spiral as it will not be able to sustain itself.....There did not seem to be any major difference in soft or hard water results in amounts of organisms living and their numbers.... temperatures can make a difference.... oxygen levels as well.....

The KWAS Study mentioned is cited as : Aquarium Nitrification Revisited: Thaumarchaeota Are the Dominant Ammonia Oxidizers in Freshwater Aquarium Biofilters. The authors are from the Department of Biology, University of Waterloo, Waterloo: Laura A. Sauder, Katja Engel, Andre P. Masella, Richard Pawliszyn, Josh D. Neufeld, with the exception of Jennifer C. Stearns, who is with Department of Medicine, Faculty of Health Sciences, McMaster University, Hamilton.
2011, PLoS ONE 6(Cool: e23281. doi:10.1371/journal.pone.0023281


Ammonia is a toxic metabolic waste product excreted by fish and other aquatic organisms. Ammonia toxicity can threaten aquatic ecosystem health and is a particular concern for relatively closed ecosystems, such as aquaculture operations and home aquaria, in which ammonia can quickly accumulate to lethal concentrations in the absence of active nitrification. The unionized form of ammonia (NH3) is particularly toxic to fish; stress, disease, and death may be associated with concentrations that exceed 0.1 mg L21 in aquarium and aquaculture systems. In order to convert ammonia to nitrate, aquarium biofilters are designed to promote the growth and activity of nitrifying populations due to the high surface area of filter support material (e.g. sponge, ceramic or polymer) and rapid flow rates of aerated water. Despite their importance to fish health and identical function within many industrial biofilters, including aquaculture and wastewater treatment, little is known of the microorganisms catalyzing nitrification in association with aquarium biofilter support material.

Hovanec and DeLong used nucleotide technique (probes) to target bacterial nitrifiers in freshwater and saltwater aquarium biofilter DNA extracts. Although Nitrosomonas-like bacteria from the Betaproteobacteria were associated with the saltwater aquaria in their study, they did not detect these bacteria in most of the freshwater aquarium biofilter extracts tested. They concluded that ‘‘the bacterial species responsible for nitrification in simple freshwater systems remain unknown’’.

Subsequent studies determined that Nitrosomonas spp. could indeed be enriched from freshwater aquarium biofilters, suggesting their potential involvement in ammonia oxidation under in situ conditions. Since the discovery of ammonia-oxidizing archaea (AOA), two studies have investigated the presence and diversity of both AOA and ammonia-oxidizing bacteria (AOB) in marine biofiltration systems. The study authors provide further background to posit that AOA (ammonia-oxidizing archaea) outnumber bacteria (AOB) in many terrestrial and aquatic environments. Although nitrification is the primary function of aquarium biofilters, very few studies have investigated the microorganisms responsible for this process in aquaria. The authors hypothesize and set out to provide evidence that AOA dominate freshwater aquarium biofilters and play an important role in aquarium nitrification.

Significance :

The present study has generated data that challenge decades of common knowledge regarding nitrogen cycling within aquarium filtration systems and solves outstanding questions remaining since Nitrosomonas spp. were undetected in freshwater aquaria These results provide first evidence for the important role of AOA in freshwater aquarium filtration and suggest possible niche adaptation of AOA to conditions associated with freshwater aquarium biofilters.

Alexmtl Aug 23rd 2013 08:39 PM


What we thought were processes dominated by Nitrosomonas and Nitrobacter is therefore invalid. "Archaea" are not bacteria but are one-celled sister prokaryote organisms in the classification schema.

Alexmtl Aug 23rd 2013 09:11 PM


The aerobic or anaerobic question ?

Now that we know that AOA (archaea) plays a crucial and dominant role in aquarium nitrification, we can believe that the process is capable of aerobic and anaerobic response. Reference : Francis et al, The ISME Journal (2007) 1, 19–27, New processes and players in the nitrogen cycle: the microbial ecology of anaerobic and archaeal ammonia oxidation .

The new twist to the nitrification story is anaerobic ammonium oxidation (anammox). Although anammox activity has yet to be measured in soils, the occurrence of anammox in a broad array of aquatic environments suggests that this process is truly ubiquitous, and it seems likely that anammox will be found in virtually any N-containing ecosystem with a pronounced suboxic zone or chemocline. In addition to their widespread distribution, anammox bacteria appear to be far more metabolically versatile than previously thought: these organisms have the capacity to couple the oxidation of various organic acids to the reduction of nitrate.

AOA (archaea), AOB (bacteria), anammox bacteria and denitrifiers all appear to possess nitrite reductase (nirK/S) genes, therefore all can contribute to a biofilter system under diverse conditions.

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Re: Bacteria Questions

Post by Ursus sapien on Mon Sep 09, 2013 9:11 am

this is awesome! Thank you for arranging to have this post copied here.
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