Aspartic Acid in the aquarium

garbled

New member
So, after reading your article, I have to wonder, has anyone actually tried manually adding aspartic acid?

Do you have an excerpt or copy of that article you could post?

Assuming I wanted to fiddle around with the idea, any idea where I could buy aspartic acid? ( I almost think Hi-Health/GNC would be a place to start ).
 
Is this an article of Randy? Where can I find it.

Many hobbysists already dose aspartic acid in their tank for several years now by using a product with a relatively very high content of aspartic acid. They have very good results.


Aspartic acid (but also e.g. glutamic acid) is a.o. a very good natural "glue" for calcium carbonate.
 
He is referring to this article that describes the chemical mechanism of calcification.

http://www.advancedaquarist.com/issues/apr2002/chem.htm

It turns out that some of the organics thought to be important for calcification include an unusually large number of aspartic acid residues, and that aspartic acid can sometimes become limiting to these organisms since they do not make it themselves.

I think that a health food store is a good place to look. Just check the label to make sure that it doesn't also contain silica, silicates, or phosphates as ingredients, since these are often used as excipients to facilitate tabletting, etc.. Of course, if you work for a company, you can order it from many chemical companies like Sigma.

Habib:

What products contain large amounts of aspartic acid?
 
Randy,

Thank you for the reference.

What products contain large amounts of aspartic acid?

;) :D It is from a company which I know very well.
 
I'd suggest starting low. The drawback might be that the aspartic acid has nitrogen in it, and it may end up partially as nitrate.

If it were me, I'd dose something like 1 g in a 100 gallon tank, and see what happens a week.
 
Randy,
OK, maybe after you look the article over, we can discuss it's merits!

Yes, I like to. :cool:
Can we discuss the whole article? And can it be done here?
 
Since the remainder of the thread is here, this is a fine place. The authors forum at reefs.org is also an appropriate place. Where ever you like!:)
 
Randy,
Before starting the discussion I will give some data and will see if I can upload some graphs and more data the coming days.

References can be given if you need them.
For the sake of clarity: all data presented here have been obtained by others.

Amino acid composition of various carbonates in residues/1000.
I will give here only the three most abundant ones.
Total amino acids in micromoles/g CaCO3 based on all protein building amino acids.

Hydroides (Serpulid)(Worm tubes):
Aspartic acid 213, Glutamic acid 120, Glycine 102. Total 8.4

Porites (Sceleractinian, Coral):
Aspartic 344, Glycine 114 , Glutamic 100. Total 2.9

Eunicea(Alcyonarian, coral):
Aspartic 745, Glycine 79, Alanine 60. Total 17.2

Oolites (Bahamas) Non biogenic!!!!!!!!:
Aspartic 302, Glycine 139, Glutamic 109. Total 3.8

Aragonite Needle mud (Bahamas):
Aspartic 313, Glycine 141, Glutamic 121. Total 21.8

Otoliths (Fish)
Aspartic 162, Glutamic 170, Glycine 125

Roughly there is little difference in the amino acid composition of carbonates formed biologically and those deposited chemically.

I therefore consider it highly likely that these amino acids also occur in the water.


Aragonite ---> Calcite transformation

Thermodynamically PURE Calcite is more stable than PURE Aragonite.
When Aragonite is kept dry the conversion to calcite would take millions of years below say 100 C.

However in the presence of water (50 ââ"šÂ¬Ã¢â‚¬Å“ 100 C) the transformation requires just hours.

In a study the kinetics of recrystallisation have been measured at a temp of 66 C in the presence of different amino acids.

Transformation to 100% calcite (blanc) 22 hours.
In the presence of serine 7 hours
In the presence of glycine 8 hours

In the presence of asparaginic and glutamic acids : after 25 hours 3% recrystallised to calcite. That is 97% is still Aragonite.
 
Habib:

Amino acid composition of various carbonates in residues/1000.
I will give here only the three most abundant ones.
Total amino acids in micromoles/g CaCO3 based on all protein building amino acids.


Can you explain what this is again? Is this CaCO3 analyzed for amino acids? The amino acids are precipitated into the structure or something?
 
Randy,
Can you explain what this is again? Is this CaCO3 analyzed for amino acids? The amino acids are precipitated into the structure or something?

It is the amino acid composition of the 3 most abundant ones in the CaCO3 of the mentioned organisms or precipitate.
I have data on the other amino acids as well.

The amino acids are from the organic fraction (NOT the tissue) of the CaCO3.

I expect to send a scan of graphs tomorrow (when I am back to work) showing the aspartic acid residues/1000 in HCl etchings of a oolite.

Also a scan of the Aragonite--> calcite transformation. The graph is more illustrative and accurate then the data I gave you.

It was my impression, from your references, that you would not have data I gave in the previous post.
I tought that the discussion could be easier when you already would have these data.

Do not hesitate to ask if it is not clear.
 
It was my impression, from your references, that you would not have data I gave in the previous post.

You are correct. Once you post what you have, I'll be happy to discuss its implications.
 
So the suggestion is that there is aspartic acid, or aspartic acid-containing proteins, that absorb onto both biological and abiotic CaCO3. Interesting. Perhaps that is why corals use it as they apparently do.

Still, I'm not sure this type of data bears on whether aspartic acid concentrations might be limiting or not to the growth of a coral, does it?
 
So the suggestion is that there is aspartic acid, or aspartic acid-containing proteins, that absorb onto both biological and abiotic CaCO3.
Yes.

Still, I'm not sure this type of data bears on whether aspartic acid concentrations might be limiting or not to the growth of a coral, does it?
Not the given data.

Biological deposited minerals go hand in hand with a organic matrix. E.g the organics associated with silicate depositing organisms such as organic coating of diatoms and sponge spicules contain relatively more serine, threonine and glycine compared to cell contents or tissue.
Serine and threonine (both hydroxyl containing) are likely candidates for Si4+ coordination. (Off topic: would they be adsorbed on glass?, could this cause diatom growth on glass?)

The primary structure of many proteins regularly reveals serine successions: Ser-Ser , Ser-Ser-Ser, Ser-X-Ser , Ser-X-Y-Ser.
Some poteolytic and esterase enzymes have serine at the active center and threonine next to the active site. In an aorta tissue this ability is sometimnes a disadvantage for the organism since formation of silicates can be initiated.

A lot of research is going on on organic matrices in all sorts of organisms and there is indirect proof that the organic matrix is essential for bio-mineralisation. If this is true then that could be rate determining for skeletogenesis.

It is also believed/speculated that the realtive proportion of amino acids with respect to each other and the sequence determines which crystal structure is deposited.

There are also proteins in corals which inhibit CaCO3 crystallisation. E.g. the mucus of Galaxea fascicularis and some of its water soluble organic macromolecules (extracted with water from exoskelton) inhibit CaCO3 crystallisation (In vitro!).
This prevents CaCO3 deposition on the outside of the coral tissue. This might have been of importance millions of years ago when the oceans were far more saturated with respect to CaCO3.


When I try to picture the skeleton of corals over simplified in my mind I see spherulitic CaCO3 with inbetween the organic matrix. The organic matrix ensures a coherent structure can possibly give some elasticity allows absorbtion of mechanical energy and ensures that the surface is not poisoned by CaCO3 inhibiters.

I also see at it (over simplified in my mind) as a polymeric fiber. Crystalline and amorphous regions in which crystals and amorphous parts are conected by polymer chains emerging from other crystalline and amorphous parts.

It is impossible to think that coral skeleton or human bones are composed of singel crystals. Even without knowing e.g. Avrami equations for crystallisation, it is safe to assume that even under the most favourable condition the crystal size will be finite and probably be less than say a few tenths of a millimeter.
So something will be needed to bond the crystals together. A glue such as the organic matrix is very likely. Especially because the organic matrix of corals contains relatively large amount of acidic amino acids such as aspartic acid which have a high binding affinity with CaCO3 and are at least bi-functional.

Note: A few parts of this message have been cited without giving references.

For fun:
3 most abundant amino acids (resd/1000) in;
Human bone: glycine 319, proline 123, alanine 114
Human dentin: glycine 319, proline 115 , alanine 112
Human enamel(developing): proline 251, glutamic acid 142 , leucine 91
Human enamel (mature) : glycine 193 , proline 137 , serine 119
 
Habib:

So I'll try summarizing what I've gotten out of this. Thanks for posting it. I don't expect an answer to the questions, but if you have any, or even opinions, I'd be happy to hear them.

1. Aspartic acid residues, either as individual amino acids or as parts of proteins, are heavily incorporated into growing CaCO3 crystals from the ocean. It is present for both biological calcification and abiotic calcification in similar amounts. Does this result suggest that it is present in corals "accidently"? That is, that it doesn't imply any special role in corals? Or maybe this incorporation is incidental to the role that organics do play in vivo, but that these are largely not left behind.

2. That the role for organics in biological calcification could be to:

a. Prevent crystal poisoning by Mg++, phosphate, and other organics.
b. Direct crystal growth to regions where it is most desired.
c. To hold loose assemblies of crystals together in the skeleton.
d. Something else?


3. That since aspartic acid naturally binds strongly to CaCO3 crystals, that is an obvious "choice" for organisms to use in attaching organics to CaCO3 surfaces.

4. That aspartic acid may be present in the ocean and aquaria because it appears to be attached to abiotic CaCO3, but that it may still not be present in high enough concentrations for optimum growth rates. Maybe it's not present in high enough concentrations precisely because it is bonded to CaCO3 and not floating around the aquaria as much as other amino acids? Would aspartic acid be beneficial as an additive?
 
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