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Algae, Cyanobacteria and Plants - An Hypothesis?

jaypeecee

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Bracknell
Hi Everyone,

Based on a lot of observations and measurements, I'd like to put forward a suggestion/hypothesis. It is this:

Perhaps cyanobacteria (BGA) and algae need inorganic phosphate (orthophosphate)/PO4--- in order to grow and survive. But higher plants (macrophytes) can use either inorganic phosphate or organic phosphate as their source of phosphorus?

Tomorrow, I'll explain my rationale for this suggestion when I, hopefully, have rather more time. In the meantime, any initial comments would be appreciated.

JPC
 
Hi @jaypeecee Good to see you back on the forum! :) Noticed you've been off for a while.

I cant say much about BGA as I don't have any and haven't had any for a very long time - always associated BGA with immature tanks - pretty vague I know... look forward to hear your rationale here.

Cheers,
Michael
 
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Hi again...

OK, I'm already starting to see things differently. In one of my tanks, I have been closely monitoring the growth of a collection of Java Ferns. KH was maintained at 2.0 - 2.5 dKH and pH was 6.7 - 7.0, corresponding to a CO2 concentration of around 10 ppm. CO2 was running 24/7. Inorganic phosphate (orthophosphate/PO4---) had been showing less than 0.02 ppm* for three weeks. The small amount of cyanobacteria that had been present dwindled as time progressed. In the meantime, the Java Ferns were flourishing putting out new leaves every few days. And they were healthy leaves. How could this be? That's when I started to think that the Java Ferns were able to use a different source of phosphorus other than inorganic phosphate. Perhaps there was organic phosphorus in the tank water? Unfortunately, I was unable to test for that.

Now, I'm beginning to think that the Java Ferns were using stored phosphorus from what I understand to be known as luxury uptake of nutrients.

I suggest also reading the following as it is pertinent to my meanderings above (and note the date of the article below):


* JBL PO4--- Test Kit

JPC
 
PMDD :: aquarium fertilizer :: articles :: PMDD original text: Control of Algae in Planted Aquaria

Great Find :thumbup:, and interesting read/theory. I will be watching thread with interest and looking forward to more feedback esp from @dw1305 and @ceg4048 ;)
 
Hi all,
Now, I'm beginning to think that the Java Ferns were using stored phosphorus from what I understand to be known as luxury uptake of nutrients.
That would be my guess. Phosphate is <"highly mobile within the plant">.
were able to use a different source of phosphorus other than inorganic phosphate. Perhaps there was organic phosphorus in the tank water?
Polyphosphate has been <"used as fertiliser">, but I know no more.

cheers Darrel
 
Great Find :thumbup:, and interesting read/theory. I will be watching thread with interest and looking forward to more feedback esp from @dw1305 and @ceg4048 ;)
Karl,
These are excerpts from messages from the venerable website The Krib
A lot of the data is from the experiments of Paul Sears and Kevin Conlin. These guys were great and they brought us the original Poor Man's Dosing Drops (the first D in PMDD actually is the first letter in a famous company's dosing drops but the acronym was changed to avoid litigation). In any case Sears and Conlin did not go far enough because at that time (20 years ago) there had not yet been any correlation made between filamentous algae and CO2, AND both of these guys suffered from a mind set against PO4. That is why they developed PMDD to be devoid of PO4 and is a failure unless the hobbyist's water source is high in PO4. It was later rectified by others to be "PMDD+PO4", which is very similar to EI.
In many of their case studies CO2 related algae appeared, which they did not recognize as being CO2 related and they attributed the appearance of the algae to what we now know to be unrelated causal factors, such as Fe and so forth.
ALL filamentous algae and Red algae is caused by poor CO2. They were unaware of that 20 years ago. Folks were using DIY yeast CO2 and so suffered greatly with algae, clueless of the cause.

Any organic nutrient source is essentially trapped within the molecular structure of organic objects, such as feces, uneaten food, detritus and plant matter. These are only released in the water when bacteria have broken down the material to get at the nutrient. So using organic nutrient sources is a very bad idea because the environment has to degrade in order for the nutrient to be made available. Plants do not typically uptake organic molecules. The uptake and metabolic pathways are typically selective and specific to the nutrient molecule of interest. That means there is a special NO3 channel, a special PO4 channel, and so forth. The PO4, or NO3, or NH4 ion must not be hidden or embedded within another molecule. The plant would interpret that molecule to be pollution. Inside the plant, however is a different story. Nutrient ions that are toxic are chelated using organic molecules to shield the plant from toxicity and are then delivered to the site where they are released and used in whatever chemical reaction is required of that ion. All the micronutrients are actually highly toxic metal ions. NH3 is toxic as hell, so it is chelated and then broken down into amino acids or their precursors as quickly as possible. NO3 and PO4 are non-toxic and can easily be stored without the need for chelation.

So one must be very careful using historical data that has long since been disqualified. Twenty years from now we will understand things that we do not yet understand now. If we continue to draw conclusions based on this type of data, not recognizing their origin, relevance or context, then we are doomed to repeat the very same failures.

Cheers,
 
Hey @jaypeecee

I actually admire the fact that you are willing to test your suspicions, most folk don't and simply take things as read. I do agree with Clive that one should be careful about drawing definitive conclusions from one specific result though.

It will be interesting to see how the ferns fair in the long term once their nutrient stores are depleted, it would also be interesting to see at some point in the future what effect the addition of P04 makes to this experiment.
 
Hi all,
It will be interesting to see how the ferns fair in the long term once their nutrient stores are depleted, it would also be interesting to see at some point in the future what effect the addition of P04 makes to this experiment.
You could potentially run your tank phosphate (PO4---) depleted and <"I may already do this unintentionally">.

It would be fairly easy because
This would mean that if you decided your plants were phosphorus (P) deficient an addition of PO4--- ions (via KHPO4 etc) would lead to a very rapid growth response, because the plant can transport the phosphorus to the new leaf tissue etc.

The main issues would be:
  • Recognising that restricted plant growth was caused by P being <"Liebig's limiting nutrient">.
  • Accuracy of measurement of PO4---
I've never kept a high tech tank. or aimed for optimal growth rate, but the success of many EI users would suggest that there is more to it than just the <"level of PO4--- ions"> in the water column.

cheers Darrel
 
Fell into a rabbit hole, went down fairly deep, I’m back up now and this is where I went!

When levels of available Orthophosphate are low there is an increase of Phytic Acid production within the plant, when the levels of orthophosphate increase there is a drop in phytic acid production. Phytic acid is a large molecule that has a caged structure that has a high affinity for filling that cage with a metal ion thus chelatory abilities.

10FBCD7B-1C2E-4B9F-8248-CFADEE622AF8.png


This is a complex Organic Phosphate molecule and it is specialised for life mechanisms to release these bonds to get at the Phosphate, it can be achieved but it requires a Phytase to accomplish this, the Phytase is an Enzyme.
287DE3A6-3F4E-4D39-AF56-B03FB2E69D18.jpeg

It is produced by some but not all organisms, particularly absent in non-ruminant animal species including fish (there’s some outliers). The specific Phytases required to reduce Phytates are called β-Propellor Phytases.

7F9FB4B6-C16E-4510-AEB5-083D54F76491.jpeg


Here’s the β-Propellor Phytase tree of life.

19F2AA77-F71B-4B0D-9A8B-19E57549FAAF.jpeg


Plant produced Phytases are represented only by the groups PAPhy and HAPhy, with the predominant variety in use being PAPhy (160 against 31). The others are produced by mychoriza, yeasts, phages and bacteria (including cyanobacteria which has a foot planted in two realms).

The suggestion is that increased eutrophic conditions allow the above non plant actors in these systems to take greater advantage of any phytate present in the water column which is unavailable for plant uptake and reduce it back to orthophosphate, they have a competitive advantage over plants when it comes to doing this.

:)
 
Fell into a rabbit hole, went down fairly deep, I’m back up now and this is where I went!
Hi @X3NiTH Your chemistry knowledge and posts, as always, are very educational, but this one I feel like I would have to study up for a couple of months at least to understand. Is there a conclusion / hypothesis in there vs Cyano?
You could potentially run your tank phosphate (PO4---) depleted
Hi @dw1305 What exactly does it mean to run the tank PO4 depleted? Does it mean that there are no PO4 available in the water column - as in if you test for PO4 you get a zero reading and your essentially relying on the phosphate coming from organics (livestock/plant waste) as opposed to dosing?

Ok, I am just trying to ask some questions that may also help others that, like me, are bio-chemistry challenged, but wish to learn more :)

I do not have enough knowledge to contribute to this, but I will say that high consistent weekly dosing of PO4 (currently dosing 10ppm PO4 with KH2PO4 down from about 20ppm/wk) in both my tanks have not caused any problems whatsoever - on the contrary it has helped eradicating GSA and probably other algae as well, of course all in combination with dosing other ferts in abundance, low light intensity, good flow and overall better maintenance.

Cheers,
Michael
 
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Hi all,
Is there a conclusion / hypothesis in there vs Cyano?
There is, it is this bit:
Plant produced Phytases are represented only by the groups PAPhy and HAPhy, with the predominant variety in use being PAPhy (160 against 31). The others are produced by mychoriza, yeasts, phages and bacteria (including cyanobacteria which has a foot planted in two realms).
The phytases are enzymes required to break down the phytic acid containing the PO4--- and all though there are a range of these, only two of them are found in green plants.
The suggestion is that ............ (non-plants) can take advantage of any phytate present in the water column which is unavailable for plant uptake and reduce it back to orthophosphate, they have a competitive advantage over plants when it comes to doing this.
Certainly plausible.
What exactly does it mean to run the tank PO4 depleted?
In my case <"all the nutrients are depleted">, I don't ever know which is Liebig's limiting one, but it is most likely to be <"nitrogen (N), potassium (K)"> and or <"magnesium (Mg) or iron (Fe)">
Does it mean that there are no PO4 available in the water column - as in if you test for PO4 you get a zero reading and your essentially relying on the phosphate coming from organics (livestock/plant waste) as opposed to dosing?
I don't actually know, because I don't regularly measure the PO4--- level, but I'd guess the plants are grabbing the phosphate ions when they are available and then <"shuffling them around the plant after that">.

cheers Darrel
 
I actually admire the fact that you are willing to test your suspicions, most folk don't and simply take things as read. I do agree with Clive that one should be careful about drawing definitive conclusions from one specific result though.
Hi @John q

My background is in the physical sciences so I try to understand to the best of my ability what my eyes are seeing - if it interests me sufficiently! It is certainly true that no cast-iron conclusions can be drawn from one set of data - empirical or otherwise. If my observations stimulate discussion and, even better, encourage others to repeat a similar experiment, then that makes it all worthwhile.

JPC
 
Hi @X3NiTH Your chemistry knowledge and posts, as always, are very educational, but this one I feel like I would have to study up for a couple of months at least to understand. Is there a conclusion / hypothesis in there vs Cyano?

Yes this is deep into the realms of Organic Chemistry and my grasp of this is less than tenuous at best, the days reading began with an observation I see with Cyanobacteria. It began with basic chemistry and how Cyano prefers to assimilate Ammonia/Ammonium first and when these levels are tending toward zero it starts on Nitrate. In order to grow tissue quite obviously phosphate is going to be required and if a system is run with very little additional orthophosphate or tending to zero then you are only left with organic sources. It’s when you start to look at the differences between the Inorganic forms of Phosphate and the Organic forms in the water column and the fact that plants only uptake orthophosphate that there’s more to the rabbit hole.

C6CB1469-10BC-465F-9C23-698C9C8BABEA.jpeg


Looking into this further in relation to nutrients in aqueous solution I was wholly dissatisfied with this statement on Organic Phosphate -

EFA50E62-ABA5-4B5B-AB36-8DF8E84D5DEE.jpeg


There is nothing minor about Phytic Acid, a plant produced chelate able to cage a metal ion (I’m going to point my finger at Iron) it’s exceptionally stable and environmentally persistent. Phytate can end up in the water column as a byproduct of tissue loss and destruction, plants can’t directly utilise this Phytate it requires a biological intermediary to disassemble the molecule to make the phosphate available, if Cyanobacteria can utilise this water column Phytate directly as a source of phosphate then how would it do this, cue the Phytases.

This is the advantage Cyano has over plants with its exceptional ability to directly scavenge and utilise sources of Organic Phosphate and the metal ions contained within with no intermediary required to do so. I have a feeling that Iron is the main metal ion that is being targeted for.

:)
 
It will be interesting to see how the ferns fair in the long term once their nutrient stores are depleted, it would also be interesting to see at some point in the future what effect the addition of P04 makes to this experiment.
Hi again, @John q

I have made a note of your comments and hope to report back on this.

JPC
 
I forgot to add that Phytate is abundant in Fish Food! If you have lots of fish then there will be lots of Phytate and depending on how good or bad nitrification processes in your filtering system is there could be abundant Ammonia/Ammonium.

:)
 
I forgot to add that Phytate is abundant in Fish Food!
Hi @X3NiTH

Indeed, phytate is everywhere - well, not literally! Take a look at this:


I've long been concerned about the amount of phosphate in fish food - particularly the processed foods. A good few years ago, the big names in fishkeeping were making a big thing about their low phosphate fish foods.

JPC
 
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