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Cyanobacteria Identification - At Last!

jaypeecee

jaypeecee

Member
Joined
21 Jan 2015
Messages
2,912
Location
Bracknell
Hi Folks,

Like many other aquarists, I have had cyanobacteria (aka 'BGA') grow in my tanks. And I started reading about this stuff. Of course, I initially thought BGA was algae. Why else would it be known as BGA (Blue-Green Algae)? But I later discovered that it's not an algae at all. It's a bacteria masquerading as algae! So, I set about trying to eradicate it from my tanks. Better still, prevent it from growing in the first place. But, then, I discovered that there was more than one Genus of cyanobacteria.

I had read in some old material from that great resource - The Krib - that Oscillatoria had been found in some users' tanks. So, yesterday, I removed a sample of this stuff and under my microscope it went. At 125X magnification, I was able to confirm that my sample of cyanobacteria was indeed Oscillatoria. I identified it by its distinguishing characteristic - the tips of the long, dark blue-green filaments oscillate from side to side, hence its name. It also breaks up into fragments. Unfortunately, I don't have the luxury of a camera or camera mount on my second-hand school microscope.

Mission accomplished.

JPC :geek:
 
I should really have said - first stage of mission accomplished. Now, I need to work on a reliable solution to this persistent nuisance.

JPC
 
Hi Folks,

It turns out that this stuff is potentially much more than a nuisance. Like some other cyanobacteria, Oscillatoria produces cyanotoxins. Please see:

http://oceandatacenter.ucsc.edu/PhytoGallery/Freshwater/Oscillatoria.html

Apparently, "Oscillatoria can produce both anatoxin-a and microcystins", according to the above reference. So, I then checked out each of these two cyanotoxins and here are links to Wikipedia:

https://en.wikipedia.org/wiki/Anatoxin-a

https://en.wikipedia.org/wiki/Microcystin

At this point, I need help in trying to determine if there are any serious implications of what initially appeared as a nuisance, albeit a major nuisance at times.

Just recently, I lost some German Blue Rams and Panda Garras - all very suddenly. I did have some cyanobacteria in that tank. Both species of fish exhibited a darkened colouring and what appeared like paralysis as they sat almost motionless on the aquarium substrate. All my other fish - Cardinal Tetras, Otocinclus, Pygmy Corydoras, Siamese Algae Eater, Corydoras habrosus were fine.

All suggestions and thoughts welcome.

JPC
 
kilnakorr said:
You could be on to something. A quick find showns cyano bacteria can lead to fish death:
https://www.sciencedirect.com/science/article/pii/S1687428513000046

Rams are usually located at the bottom of the tank, so maybe more exposed to the toxins?
Click to expand...

Hi @kilnakorr

Many thanks for the link, which I have scanned. It looks very relevant. I will read it and re-read it. This is such a specialized area and it lies outside my area of expertise. But, I have made the observation and I'm in little doubt that what I and A N Other have seen was Oscillatoria.

JPC
 
Hi Folks,

I'm digging deeper into this conundrum. I've started some experiments to see if I can control/eliminate this Oscillatoria menace. Ambitious, I know but I'm fed up with this unsightly stuff. And, if it's potentially toxic to my tank inhabitants, it's not a welcome visitor. I don't want to resort to adding chemicals if I can avoid it. Particularly commercial preparations using undisclosed (proprietary) chemicals. I was OK previously about trying Easy-Life Blue Exit as the active ingredient is named as salicylic acid. I am exploring the link between cyanobacteria and heavy metals. I also have a hunch that lighting spectrum may exacerbate the growth of the blue-green peril.

NOTE: I have no fish, shrimps or snails in my experimental tank.

JPC
 
kilnakorr said:
A solution without chemicals is always preferable in our tanks. Do you count antibiotics as chemicals?

Some interesting reading on a problem with this stuff in ponds. Solution seemed to be ultra sound.:bookworm:
http://www.efficientsonics.com/wp-c...illatoria_using_a_PondTec_ultrasound_unit.pdf

Unfortunately not many details, and getting a home-kit ultra sound device might be hard to find😵
Click to expand...

Hi @kilnakorr

My head is swimming with cyanobacteria information - well, not literally!

I don't think of antibiotics as chemicals per se. But, I think the consensus is that they are to be avoided as they encourage new antibiotic-resistant bacteria strains. But, I stress that I'm just dabbling here. My background is not in the life sciences but the physical sciences. So, I just read and read and read - just like someone would read novels, for example. When I get really stuck (quite often), I turn to @dw1305 for help.

I was aware of the use of ultrasound and I have a copy of the article above but I'd forgotten that it dealt with Oscillatoria - so thanks a bunch for the reminder!

JPC
 
Hi all,
jaypeecee said:
When I get really stuck (quite often), I turn to @dw1305 for help.
Click to expand...
Not a lot of help here, I'm afraid.

Cyanobacteria definitely produce toxins and you get toxic "blooms" <"where Oscillatoria spp. are present">. They are also a <"marker of eutrophic water"> in the natural environment, and a local garden centres pet section used to have disgustingly dirty tanks, with <"truly fluorescent BGA">.

After that we are back into the <"shades of grey"> world, where cause and effect are much more difficult to prove. Fingers crossed I've never suffered from a BGA outbreak, but I have sometimes found a smear on the <"older leaves of Pistia">.

If people have access to <"Harmful Freshwater Algal Blooms, with an emphasis on Cyanobacteria">? It looks a pretty decent reference.
Dr Mike Oxgreen said:
I’m betting that one notorious chemical will be involved, no matter what solution you choose: dihydrogen monoxide.
Click to expand...
That is definitely true, because if you have liquid water you will also have Cyanobacteria.
Dr Mike Oxgreen said:
Cyanobacteria are often associated with low nitrates, but I don’t know if that is specific to one or more particular types of Cyanobacteria.
Click to expand...
It is, Oscillatoria isn't nitrogen fixing, it is "non-diazotrophic".

cheers Darrel
 
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Dr Mike Oxgreen said:
Cyanobacteria are often associated with low nitrates, but I don’t know if that is specific to one or more particular types of Cyanobacteria.
Click to expand...

Hi @Dr Mike Oxgreen

Yes, I think low nitrate is sometimes/often stated as being one of the causes of cyanobacteria outbreaks. As Oscillatoria would appear to be prevalent in freshwater aquaria, they may be totally dependent on nitrate as they seem unable to fix atmospheric nitrogen. I say 'seem' as the Genus, Oscillatoria includes no less than 100 known species! My bwain hurts as John Cleese would say! (spelling error intentional). So, I think the 'low nitrate' cause may be a bit misleading in the case of Oscillatoria. References to 'low nitrate' imply that higher nitrate is OK but I can't see the logic in that. More nitrate, more BGA?

JPC
 
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Hi Everyone,

I may have gone quiet in my pursuit of a method for (hopefully) eliminating cyanobacteria in general and, specifically, Oscillatoria. But I am still beavering away with this. I am trying a two-pronged approach based on the lifecycle of Oscillatoria. I hope to have some results within the next couple of weeks. I am prepared for abject failure but, as they say, nothing ventured, nothing gained!

JPC
 
Hi Folks,

I thought it was time for an update. So, here goes...

Virtually all the BGA/cyanobacteria has now gone from my experimental tank. I removed a tiny sample this morning and examined it under a microscope as before. There were no signs of oscillation of the filaments that I had seen previously. I spent probably 15 minutes carefully watching this stuff and this tangled mass was stationary. I haven't added any fertilizers to this tank since this experiment started on 13 April. I had wanted the BGA to use up any fertilizers that were in the water from the outset. The tank is in a brightly-lit room with no additional light over the tank.

My approach so far has been to use Easy-Life Blue Exit in conjunction with an in-tank UV-C sterilizer. My thinking behind this is to kill off the visible BGA filaments (sitting on the substrate) with the Blue Exit and also to ensure that any free water-borne fragments are drawn into the sterilizer where they are irradiated and killed with a dose of UV-C 'light'. I have used Blue Exit before in my community tank where it certainly reduced the amount of BGA in the tank. Its active ingredient is salicylic acid:

https://en.wikipedia.org/wiki/Salicylic_acid

Many research papers later, I have learned that there appear to be two minerals/elements in particular that are thought to be essential to the survival of cyanobacteria. So, I need to pursue this further.

That's all for now.

JPC
 
Micronutrient effects on cyanobacterial growth and physiology

4A9FF0E1-76F5-47BE-8442-22E46156E193.jpeg

This would suggest that using an Iron chelator in a pH environment that makes it always bioavailable where Nitrates are also present increases cyano growth. Change the chelate to a more temporary version and use it in an environment that makes it less bioavailable may restrict cyano growth. Increasing background concentrations of Manganese and Copper in an Iron limiting environment may reduce or hopefully eliminate cyano altogether.

Pretty much all Tap water is remediated to remove Manganese if it’s present in the supply because concentrations as little as 0.05ppm makes water taste foul.
 
Hi @X3NiTH

Many thanks for your feedback.

I was looking at that very scientific paper today. The thing about Oscillatoria, which is what I have identified in my tank, is that it is not a nitrogen-fixing cyanobacteria. BTW, the maximum Mn level in my tap water in 2018 was 10.20 micrograms/l.

JPC
 
So quite palatable water!

Just so we’re on the same page 10.20micrograms/L = 0.0102milligrams/L (ppm).

I was thinking that tap water that is remediated and has a persistent low level of Mn and Fe in it being used for water changes to help reduce ammonia/nitrate loading in water that has a lot of waste producers may exacerbate the growth of cyano if it’s present in the system.

Of all the compounds that Cyanobacteria can produce they share one specific characteristic, they all use nitrogen as the foundation from which to build them. Oscillatoria uses N in the production of Anatoxin otherwise known as Very Fast Death Factor (every bit as bad as it sounds as it’s a neurotoxin, dig way down deeper into that rabbit hole and you’ll find a causal link with sporadicCJD).

So it would be good to find a way not just to eliminate this from tanks but to keep it out by creating the environment to prevent it by feeding the tank the elements cyano doesn’t like and limiting the ones it does (or adjust the element to element ratios). Easy Peasy then 😉

🙂
 
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