Inorganic Carbon to Reduce Phosphate & Nitrate?

[pjf]

Before vodka and sugar dosing became the vogue, carbon was dosed and continues to be dosed in aquariums with the use of:

• calcium reactors
• CO2 injection with pH controllers
• acetic acid & kalkwasser solutions

While the intent is to maintain calcium, alkalinity, and pH levels, these systems also serve to add carbon dioxide and bicarbonates to the aquarium. When inorganic carbon is dosed judiciously or with the use of controllers, pH swings and carbonate precipitation can be avoided.

Can these systems reduce phosphate and nitrate by promoting growth of autotrophic bacteria in the water column to be skimmed?

[bertoni]

That's an interesting question, but I doubt that most tanks are carbon-dioxide-limited, in any case. For that to happen, the pH of the tank would have to be very high. That could happen with a large refugium, but that's uncommon in saltwater tanks. Sugar and vodka are intended for heterotrophic (or mixotrophic) bacteria.

[wong BANTEN]

In theory, CO2 will became HCO3........
Why dont you add H2CO3 instead of CO2?
So maintaining pH and concentration of CaHCO3 will more accurate.
promoting bacteria by that system only additional related effect, and there will be more complicated.

[pjf]

Carbon dosing for the purpose of maintaining alkalinity, calcium and pH levels is commonly done in a number of ways:

1. Kalkwasser dosing with pH controllers that use CO2 injection
2. Calcium reactors that use CO2 controllers to dissolve calcium carbonate
3. Acetic acid (white vinegar) & kalkwasser.

In the first two methods, CO2 is injected into either a reactor or to the aquarium itself while limewater is produced or dosed. A CO2 controller maintains the proper pH level. CO2 or its derivatives, carbonate (CO3), bicarbonate (HCO3), and carbonic acid (H2CO3), serve as sources of inorganic carbon.

When acetic acid (white vinegar) is dosed with kalkwasser, the vinegar is consumed biologically and produces CO2 to prevent the kalkwasser from raising the pH too high (Delbeek & Sprung, "The Reef Aquarium," vol. 3, p. 220). Delbeek and Sprung hypothesize that the use of vinegar to boost kalkwasser effectiveness can promote uptake of phosphate and nitrate by bacteria (ibid, p. 275).

[Boomer]

I do not disagree with that pdj. I think were we are stuck at is how much will they remove.

wong

In theory, CO2 will became HCO3........

Yes if the pH rises and if it rises more it becomes CO3-- but that shift has no effedct on Alk, just pH. There is just a shift in their ratios. The only time CO2 becomes HCO3 is if reacts with something like kalk

Ca(OH)2 ---> Ca++ + 2OH

2OH + 2CO2 = 2 HCO3-, which rises the pH and Alk.

Why don't you add H2CO3 instead of CO2?

There is not such thing really accept in solution. You can't go buy any H2CO3. Adding CO2 water creates H2CO3. So they only thing would be carbonated water or Seltzer Water.


concentration of CaHCO3

Same with this there is no such thing accept as an ion pair

:Ca::HCO3: , where : = surrounded by 1-2 layers of water molecules.

[mesocosm]

Greetings All !

Originally posted by bertoni
That's an interesting question, but I doubt that most tanks are carbon-dioxide-limited, in any case. ...

Bertoni's doubt is correct. Unless something is seriously out of wack ... as in Tank-O-Death out of wack ... marine aquaria are simply not CO2 limited (... or inorganic carbon limited, for that matter).

Organic carbon limitation is an entirely different issue, but at this point we're no longer talking about autotrophic marine bacteria ... we're now talking about heterotrophic marine bacteria (in all their various forms).

Originally posted by pjf
... Can these systems reduce phosphate and nitrate by promoting growth of autotrophic bacteria in the water column to be skimmed?

While suspended "free-living" bacteria can be powerful nutrient scavengers in the water column, CO2 isn't the issue. Consider ...

... CO2 can be fixed ... the fixation is not "growth bound."

...only a limited amount of CO2 can be fixed. This amount is approximately 40 µl. CO2 per 100 micrograms bacterial nitrogen. After a culture has utilized this amount of CO2 it no longer has the ability to fix CO2 but releases it during its respiration.

... The physiological condition of the cell is of considerable importance in determining CO2 fixation.


Extracted from:

Studies on the Metabolism of Autotrophic Bacteria
II. The Nature of the Chemosynthetic Reaction
K. G. Vogler
The Journal of General Physiology, Vol 26, 103-117, 1942
http://www.jgp.org/cgi/content/abstract/26/1/103

In general terms, it turns out that nitrogen-limitation is the primary limiting variable in terms of autotrophic marine bacterial growth. But generalizations can quickly become misleading in the universe of marine bacteria. Many marine bacteria are very substrate (nutrient medium) specific, so much so that the particular substrate (with its specific element or compound) becomes the primary limiting variable. Examples of this include IOB (iron-oxidizing bacteria), and SRB (sulfur-reducing bacteria). Additionally, the environment that a marine bacterium finds itself in can dramatically influence its metabolic behavior (... you can now add shear force, mass transfer rate, and elemental/ionic composition of the water column to the variable mix).

For a review of the potentially dizzying set of variables involved in the distinguishing structural and metabolic characteristics of autotrophic and heterotrophic bacteria, you might wish to spend a few moments with these ...

II. The Comparative Physiology of Autotrophic Bacteria
W. W. Umbreit
Bacteriol Rev. 1962 June; 26(2 Pt 1-2): 145–150.
http://www.pubmedcentral.nih.gov/pag...45&pageindex=1

Cationic composition of 22 species of bacteria grown in seawater medium.
G E Jones, L G Royle, and L Murray
Appl Environ Microbiol., v.38(5); Nov 1979
http://www.pubmedcentral.nih.gov/art...i?artid=243589




If you're interested in "dosing" something to enrich marine bacterial metabolic behavior, you might consider something which incorporates either glutamate, or glutamine. These amino acids are oftentimes the major donor of organic nitrogen in many biosynthetic reactions involving marine bacteria. And no, I have no wish to engage the amino acid dosing pro vs. con debate (the research literature speaks for itself). Bsides, I like my fingers just the way they are ...

... intact ... ... ...


Other potential "dosing" candidates include metal ions and trace elements. The Center for Environmental Bioinorganic Chemistry (CEBIC), and the Princeton Environmental Institute (PEI), has posted some really interesting ... and readily digestible ... information in this area. Examples include:

Trace metals, enzymes, and biogeochemical cycles
Princeton Environmental Institute (PEI)
http://www.princeton.edu/~cebic/enzymecycles.html

Chelation, uptake, and binding of trace metals
Princeton Environmental Institute (PEI)
http://www.princeton.edu/~cebic/chelbindintro.html

Originally posted by pjf
... Delbeek and Sprung hypothesize that the use of vinegar ... can promote uptake of phosphate and nitrate by bacteria (ibid, p. 275).

Nothing hypothetical or controversial about the potential utility of "carbon dosing" ...

Researchers have long noted the role of "carbon dosing" in the culture of marine bacteria. For example ...

For cultivation, synthetic seawater was prepared as described by Schut et al. (48). Trace elements and vitamins were added separately. A mixture of monomers (alanine, l-aspartate, dl-leucine, l-glutamate, l-ornithine, and dl-serine [all at 1 μM]; glucose, fructose, galactose, glycolate, succinate, and mannitol [all at 10 μM]; and acetate, lactate, ethanol, and glycerol [all at 15 μM]) was added as a substrate.


Extracted from:
Culturability and In Situ Abundance of Pelagic Bacteria from the North Sea
Heike Eilers, Jakob Pernthaler, Frank Oliver Glöckner, and Rudolf Amann
Appl Environ Microbiol., v.66(7); Jul 2000
http://www.pubmedcentral.nih.gov/art...gi?artid=92109

Carbon sources ... trace elements ... and vitamins, oh my ...


And yet, in terms of the research literature, things are not as straightforward as many manufacturers, distributors, and hobbyist-practioneers would have us believe. The additon of a carbon source DOES present the opportunity to enrich the assimilatory reduction of nitrate and phosphate ... no question ... but the specifics of such enrichment pathways remain elusive. From the above referenced article ...

... Different marine bacteria react differently to confinement (13) and substrate quality and quantity (54). Active metabolism and multiplication might be terminated due to enrichment of toxic products, depletion of essential nutrients (53), and viral infection (58). The growth state of the bacteria at the time of sampling, whether they are active, starved, or dormant, may also strongly influence the success of cultivation.

In principle, for successful enrichments, the physiological requirements of the target microorganism should be known. Most marine bacteria face an oligotrophic environment, but the definitions of the needs of oligocarbophilic microorganisms are as diverse as they are difficult to justify (49). Not even the amount of organic carbon per liter sufficient for growth of oligocarbophilic bacteria is agreed upon, and the appropriate types of carbon sources are in dispute.

JMO ... sorry for the length

[Boomer]

No how did I know you were going to pop in Meso

You must have sniff program for this stuff on this forum

marine aquaria are simply not CO2 limited

Of course not as long as they can convert, HCO3- or CO3-- into CO2 or lower the pH, which shifts the carbonate system to a lower pH with more CO2. Not to mention the Alk is C source, as it is mostly HCO3- and CO3--.

Other things to read.

Bacterial Biogeochemistry by Fenchel, King and Blackburn

Mirobial Ecology of the Ocean by Kirchman

[bertoni]

Interesting post, Mesocosm! Thanks!

[pjf]

Originally posted by mesocosm


In general terms, it turns out that nitrogen-limitation is the primary limiting variable in terms of autotrophic marine bacterial growth. But generalizations can quickly become misleading in the universe of marine bacteria. Many marine bacteria are very substrate (nutrient medium) specific, so much so that the particular substrate (with its specific element or compound) becomes the primary limiting variable. Examples of this include IOB (iron-oxidizing bacteria), and SRB (sulfur-reducing bacteria). Additionally, the environment that a marine bacterium finds itself in can dramatically influence its metabolic behavior (... you can now add shear force, mass transfer rate, and elemental/ionic composition of the water column to the variable mix).

If you're interested in "dosing" something to enrich marine bacterial metabolic behavior, you might consider something which incorporates either glutamate, or glutamine. These amino acids are oftentimes the major donor of organic nitrogen in many biosynthetic reactions involving marine bacteria. And no, I have no wish to engage the amino acid dosing pro vs. con debate (the research literature speaks for itself). Bsides, I like my fingers just the way they are ...

(1) If nitrogen is the limiting factor then aquariums should not have issues with inorganic nitrogen, such as ammonium, nitrites and nitrates. Do you mean that autotropic organisms in the water column are limited by organic nitrogen, such as amino acids?

(2) Are photo-autotrophic organisms (plants, algae, bacteria) that can assimulate CO2 through photosynthesis limited by organic nitrogen, such as amino acids?

(3) In the water column, what are photosynthetic organisms that can assimulate CO2, phosphates and nitrates limited by?

[mesocosm]

Greetings All !

target=_blank>Originally posted by Boomer
... how did I know you were going to pop in Meso ...

Irrational obsession is as irrational obsession does ...

Originally posted by Boomer
... You must have sniff program for this stuff on this forum ...

Easy call ... you and Bertoni are well worth the read .

Besides, pjf's questions hit a happy nerve. The whole issue of "carbon dosing" in marine aquaria is fascinating. The distinctions between inorganic vs. organic carbon utilization are potentially useful to many aquarists ... on a lot of levels.

Originally posted by Boomer
Mirobial Ecology of the Ocean by Kirchman

Sweet ! Everyone cites Sorokin, but Kirchman is much more accessible. This is another reason I lurk regularly through The Reef Chemistry Forum (and ReefFrontiers, for that matter) ...

Boomer references are the best !



JMO

[mesocosm]

Greetings All !

Originally posted by pjf (1) If nitrogen is the limiting factor then aquariums should not have issues with inorganic nitrogen, such as ammonium, nitrites and nitrates. ...

I was talking about the limiting nutrient(s) for autotrophs, more specifically ... photoautotrophs. While the metabolic behavior of a marine aquarium's bacteria guild is a fundamental thing, the "issues" marine aquaia encounter regarding DON (dissolved organic nitrogen) seem to me to be much more related to system design, filtration tool & toy selection, bioload, and aquarist husbandry practices. I don't think there's a dosing regiment for photoautotrophs that can overcome DON problems whose root cause involve things like inadequate filtration toys, too many fish, too much feeding, and inadequate water changes.

Originally posted by pjf
... Do you mean that autotropic organisms in the water column are limited by organic nitrogen, such as amino acids? ...

Yes, but ...

Originally posted by pjf (2) Are photo-autotrophic organisms (plants, algae, bacteria) that can assimulate CO2 through photosynthesis limited by organic nitrogen ... ?

... the range of limiting variables which encompasses microalgae, marcoalgae, sea grasses, and the (potentially) 100s of different strains of marine bacteria is significant. We're talking dozens of potentially limiting variables ... complicated by the potentially inhibitory and/or enrichment effects of different variable combinations (... BTW, you can see the effects of the shifting of such limiting variable combinations as systems undergo the process of algal succession, or ... more irritatingly ... during cyanobacteria blooms).

Even so, the carbon-nitrogen-phosphorus (and oxygen) relationship of the Redfield Ratio is a useful ratio for trying to get at "tweaking" optimal performance out of microorganisms (if for no other reason than that it is the primary ratio that marine researchers have focused on).

The rub is ... aquarists aren't dealing with oceanic food webs and nutrient cycles, so they need to be much more specific in terms of the organism they're intersted in. For example, while DON is clearly a limiting variable for cyanobacteria, a microalgae like Derbasia is much more limited by either P or Fe.



JMO ... HTH

[mesocosm]

Greetings All !

Originally posted by pjf
(3) In the water column, what are photosynthetic organisms that can assimulate CO2, phosphates and nitrates limited by?

The relative concentration of DON, phosphorous compounds, a species-specific substrate (like Fe for IOB), DOM (dissolved organic material), a variety of trace elements (to a lesser degree, and also dependent upon the species/strain), and a host of environmental parameters including surface area, flow (shear force & mass transfer), temperature, pH, salinity, particulate (macro-aggregates, POM, PIM, "marine snow") type & density, allelopathic chemicals, predator-prey interactions, and ... perhaps the most significant for photoautotrophs ... the quality, intensity, and duration of light.

While it's tempting to be overwhelmed by this potentially mind-mumbing set of variables ... not to worry. Our captive marine ecosystems are much more analogous to a laboratory culture vessel than they are to full-blown, natural marine ecosystems. These relationships and interactions are describable, but the database is still under construction ... which is why threads like this are so potentially useful.


JMO

[mesocosm]

Greetings All !

Originally posted by pjf
... such as amino acids? ...

Gods of the Reef ... you may have noticed that this is dangerous ground to tread here in the Land that JohnL built. Even so, this is a subject with potentailly powerful applications for reefkeepers, so I'll take a stab at it ... but please excuse my quick and silent exit from this discussion if it degenerates. Been there ... done that ... no thanks, I gave at the office ...

...


What follows is speculative opinion. Such an opinion, along with $3.95, will get you a tall Cafe Mocha at Starbucks ...

My perspective is that the utility of dosing amino acids is that such a husbandry selection is addressing a fundamental issue ... nitrogen limitation involving marine bacteria. I contend that the fundamental benefit(s) of amino acid dosing involve marine bacteria. Why?

Buckle up ... ...

Because it is energetically more favorable to transport amino acids than to synthesize them de novo, the increased participation of extracellular amino acids in protein synthesis may result in faster growth rates and higher growth efficiencies than before the increased input of DON. ....


Clearly several parameters of bacterial metabolic processes can change before rates of DNA synthesis and bacterial biomass production “shift up” in response to an increase in DON concentrations. These parameters include transport rates, intracellular pool sizes of free amino acids, respiration, and the rate of amino acid biosynthesis. ...


One problem is that we have attempted to apply one physiological model of DON uptake to complex systems in which many parameters varied, including, for example, the species composition of the bacterial assemblages and the concentrations of dissolved free and combined amino acids. Our experiments suggest that more than one uptake system ... was present. ... in a significant number of experiments, the results were complex and suggested the existence of multiple uptake systems (Azam and Hodson 1981). ...


Extracted from:

Metabolic regulation of amino acid uptake in marine waters
David L. Kirchman and Robert E. Hodson
Limnol. Oceanogr., 31(2), 1986, 339-350
http://aslo.org/lo/toc/vol_31/issue_2/0339.pdf

Which takes us back to the interacting variables involving a carbon source ...

Since glucose usually dominates the dissolved monosaccharide pool, this suggests the importance of the polysaccharide fraction in bacterial carbohydrate utilization. There may be preferential bacterial utilization of combined carbohydrates similar to that for dissolved protein (Hollibaugh and Azam 1983; Kirchman and Hodson 1984).

Extracted from:
Bacterial utilization of total in situ dissolved carbohydrate in offshore waters.
Curtis M. Burney
Lmnol. Oceanogr., 31(2), 1986, 427431
http://aslo.org/lo/toc/vol_31/issue_2/0427.pdf

This is why I said, "If you're interested in "dosing" something to enrich marine bacterial metabolic behavior, you might consider something which incorporates either glutamate, or glutamine." Clearly, the supplementation of amino acids has the potential to present some rather exciting ... and fundamental ... "tweaking" opportunities in terms of the metabolic behavior of marine bacteria, but such dosing is not the only variable in play.

Not JMO ... this is the science ...



Even so, a meaningful read of the Kirchman & Hodson article will detail how, in addition to some straightforward increases in uptake and respiration, there are other equally straightforward inhibition pathways. We're talking mixed bag ... not a slam dunk. If you're looking for the "silver bullet" formula or ratio for maximizing assimilatory nitrate and phosphate reduction ... sorry, but I've never stumbled across anything like that in the research literature. Lots of tantilizing clues ... no directly applicable ratios or formulae.

It is also perhaps worth pointing out that any quest in search of maximizing assimilatory nitrate and phosphate reduction is going to be much more engaged with heterotrophic microorganisms. Why the focus on autotrophs?


JMO ... HTH ... sorry for the length.

[Boomer]

Meso

Have you heard of or looked into the Italian Blue Coral Method, where GRH's are added to the water. There have been many long threads on it just like the ZeoVit system here on RC

Also there have been many post here on RC (SPS forum IIRC) and there on dosing AA. Last month Chris Brighwell launched his new company, where they have AA's in their product line.

http://brightwellaquatics.com/

[mesocosm]

Greetings All !

Originally posted by Boomer
... Have you heard of or looked into the Italian Blue Coral Method, where GRH's are added to the water. ...

ROTFL ! Are those Italians wild & crazy reefkeepers, or what? You've got to love them ... and respect the demonstration of mastery.

GRHs (presuming that we're talking about so-called 'growth regulating hormones') are actually "a bridge too far" for me. Strange as it may sound coming from a reefkeeper with a bent towards the mad scientist experimentation thing ... I'm not prepared to muck with the cellular machinery on that level.

Dosing "magic potions"? ... no problem.
Dosing glucocorticoids or mineralocorticoids? Just a bit much ...

However, the chemical precursors of hormones, and the cellular mechanisms that produce hormones in corals, are issues that I'm very interested in taking a hard look at ... hence my ridiculous fascination with peptide and vitamin dosing. Also, there's another level to my twisted thinking ... the holobiont (including the bacterial microbiota). Consider this interactive relationship ...

Coral Host <--> Zooxanthellae <--> Microbiota

It strikes me that there's a potential for a better "overall" response/benefit if I dose precursors that are useable by all three components of the above relationship (as opposed to specific hormones which only impact the coral host). JMO ... this is out on the edge, folks. The research literature is hardly definitive ...

So consume this perspective with large NaCl crystals ...


On a different tangent, if anyone out there is interested in the topic of hormones as they relate to the sexual reproduction of corals, these may be of interest ...

Corals have already evolved the vertebrate-type hormone system in the sexual reproduction
Twan, Wen-Hung; Wu, Hua-Fang; Hwang, Jiang-Shiou; Lee, Yan-Horn; Chang, Ching-Fong
Fish Physiology and Biochemistry, Volume 31, Numbers 2-3, April 2005 , pp. 111-115(5)
http://www.ingentaconnect.com/conten...1?crawler=true

The Presence and Ancestral Role of Gonadotropin-Releasing Hormone in the Reproduction of Scleractinian Coral, Euphyllia ancora.
Wen-Hung Twan, Jiang-Shiou Hwang, Yan-Horn Lee, Shan-Ru Jeng, Wen-Shiun Yueh, Ying-Hsiu Tung, Hua-Fang Wu, Sylvie Dufour and Ching-Fong Chang
Endocrinology Vol. 147, No. 1 397-406, 2006
http://endo.endojournals.org/cgi/content/full/147/1/397

Maybe the Italians aren't as crazy as some have asserted ...


On yet another hormone-related tangent, reducing the stress of transshipped fish through the use of dietary supplements aimed at enriching the production of cortisols is another Bizzaro World topic I've taken a look at ... for example ...

Measurement of fecal glucocorticoids in parrotfishes to assess stress
TURNER John W., NEMETH Richard & ROGERS Caroline
General and comparative endocrinology (Gen. comp. endocrinol.)
2003, vol. 133, no3, pp. 341-352
http://cat.inist.fr/?aModele=afficheN&cpsidt=15120014


The things you can do with chemistry ...

Originally posted by Boomer
... Last month Chris Brighwell launched his new company, where they have AA's in their product line.

http://brightwellaquatics.com/

Is this the same Chris Brightwell who wrote The Nano-Reef Handbook?

Regardless, this is the kind of trend I've been posting about for quite a while now ... the blending of science and practical husbandry experience in a way that consumers in the North American marine ornamental industry have never seen before. The days of practical husbandry anecdotes dominating the implications of the research literature are going bye-bye ... a new and powerful hybrid is in the process of emerging.


JMO

[pjf]

If I understand you correctly, heterotrophic bacteria are not limited by carbon per se (CO2) but rather by organic carbons (vodka, sugar).

As for autotrophic bacteria, my impression is that dosing organic nitrogen (amino acids) to export inorganic nitrogen (nitrate) may be self-defeating.

A "silver bullet" to produce a bloom of planktonic photoautotrophs that assimilates nitrates and phosphates and can be exported via skimming appears to be elusive.

At publication of the 3rd volume of Delbeek & Sprung's "The Reef Aquarium," the jury was still out regarding vodka & sugar dosing. There was speculation that the bloom produced was nothing more than carbonate precipitation. Has that issue been resolved?

[Boomer]

Meso

Great post again and

Is this the same Chris Brightwell who wrote The Nano-Reef Handbook?

Yes, and he also just released a chem book but I have lots of issues with it. It could have been a great book. If you go to that website and look under the link "About Us" his name is at the bottom as President.

pjf

There was speculation that the bloom produced was nothing more than carbonate precipitation.

I do not know if it has or not, I'm not into this vodka, sugar stuff at all. It should have been easy enough to find out. IMHO I think it is a bloom.

[mesocosm]

Greetings All !

Originally posted by pjf
... heterotrophic bacteria are not limited by carbon per se (CO2) but rather by organic carbons (vodka, sugar).

Yes ... heterotrophic bacteria are limited by organic carbon, and potentially by another set of either elements, or compounds (dependent on the specific strain). I hasten to add that inorganic carbon containing compounds can significantly impact the metabolic behavior by virtue of their role in the environment of the bacteria (effect on pH, for example)... but not as a directly limiting factor in the way that N. P, and O are limiting factors.

Originally posted by pjf
As for autotrophic bacteria, my impression is that dosing organic nitrogen (amino acids) to export inorganic nitrogen (nitrate) may be self-defeating.

Generally speaking, yes ... if for no other reason than that if we're talking about autotrophic bacteria in marine aquaria, we're generally (but not exclusively) talking about ...

... cyanobacteria

Originally posted by pjf
A "silver bullet" to produce a bloom of planktonic photoautotrophs that assimilates nitrates and phosphates and can be exported via skimming appears to be elusive.

Specifically in terms of photoautorophic bacteria ... I would agree. But in terms of the broader, general range of "planktonic photoautotrophs", then I would disagree ... the "silver bullet" ratios for phytoplankton (as but one example of the larger set) are well-understood and documented.

There are other issues with trying to generate rapid growth phase planktonic photoautotrophs in marine aquaria, the two primary ones (JMO) are: (1) the virtual removal of life cycle stages by protein skimming, and (2) the "side effects" of the necessity for including a necessary limiting factor (as with excess silica of iron).

Originally posted by pjf
At publication of the 3rd volume of Delbeek & Sprung's "The Reef Aquarium," the jury was still out regarding vodka & sugar dosing. There was speculation that the bloom produced was nothing more than carbonate precipitation. Has that issue been resolved?

Carbonate precipitation, per se, has been pretty much dismissed. It's generally acknowledged (in the online marine aquarist community, at least) that what we're seeing with the "cloudiness" is the actual free-living (as opposed to attached biofilms) population itself, or macro-agregates which form as a result of the increase in free-living population ... or both. My opinion (... see previous Starbucks reference ...) is that what is being observed is mostly the colonization of the micro-particulates that were present in the water column at the time that the bacteria population began to bloom.





JMO ... HTH

[wilsonh]

Wow, what a fascinating thread!

Awesome stuff Mesocosm!!

A question re this comment

Originally posted by mesocosm
Greetings All !

It is also perhaps worth pointing out that any quest in search of maximizing assimilatory nitrate and phosphate reduction is going to be much more engaged with heterotrophic microorganisms. Why the focus on autotrophs?

JMO ... HTH ... sorry for the length.

I found this

Quote - "Scientific studies have shown that Nitrosomonas bacterium are so efficient that a single cell can convert ammonia at a rate that would require up to one million heterotrophs to accomplish".

Taken from
http://www.bioconlabs.com/nitribactfacts.html

OK it's an advertisement LOL, but would indicate that autotrophs can be a lot more useful than heterotrophs, assuming they got their facts right. Any comments?

[auckreef]

Can someone explain what the difference is between autotrophic and heterotrophic bacteria?

Plus how this will affect the aquarium?

[mesocosm]

Greetings All !

Originally posted by auckreef
Can someone explain what the difference is between autotrophic and heterotrophic bacteria? ...

Autotrophic
(i) An autotroph is an organism that produces organic compounds from carbon dioxide as a carbon source, using either light or reactions of inorganic chemical compounds as a source of energy.
(ii) The ability to produce organic food without eating other organisms.

Heterotrophic
(i) Obtaining nourishment from organic substances, not from food produced within the organism.
(ii) Requiring organic substrates for growth and development; being incapable of synthesizing required organic materials from inorganic sources.

I like visual aids. Wikipedia presents a flowchart for deciding whether or not an organism is autotrophic or heterotrophic here:
http://en.wikipedia.org/wiki/Image:Troph_flowchart.svg


Not to compound the issue, but it's also worth noting that there are organisms which demonstrate both autotrophic and heterotrophic behavior. Some microorganisms (Euglenoids) can absorb decayed organic material and photosynthesize ... some plants (like the Venus Fly Trap) can photosynthesize and absorb decayed organic material.





There are two other definitions that may prove helpful to this discussion ... organic vs. inorganic.

Organic Compound
An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. The name "organic" is a historical name, dating back to 19th century, when it was believed that organic compounds could only be synthesised in living organisms through vis vitalis - the "life-force". The theory was that organic compounds were fundamentally different from those that were "inorganic". While this theory has been proven wrong, the name has stuck nonetheless.

For more background reading on organic compounds ... and a wonderful listing of specific compounds ... see here (the patterns might be helpful to you):
http://en.wikipedia.org/wiki/Organic_compounds

Inorganic Compound
Inorganic compounds are considered to be of mineral, not biological, origin. Inorganic compounds can be formally defined with reference to what they are not ( ... i.e., they're not organic compounds... isn't the circular distortion of some historical definitions great?). When considering inorganic chemistry and life, it is useful to recall that many species in nature are not compounds per se but are ions. Sodium, chloride, and phosphate ions are essential for life, as are some inorganic molecules such as carbonic acid, nitrogen, carbon dioxide, water and oxygen.

For more background reading on inorganic compounds, see here:
http://en.wikipedia.org/wiki/Inorganic_compound

For a mind-numbing list of inorganic compounds, see here (the patterns might be useful to you):
http://en.wikipedia.org/wiki/List_of...anic_compounds



Not JMO ... this is the science.

[mesocosm]

Greetings All !

Originally posted by mesocosm
It is also perhaps worth pointing out that any quest in search of maximizing assimilatory nitrate and phosphate reduction is going to be much more engaged with heterotrophic microorganisms. Why the focus on autotrophs?

The comparison between autotrophs vs. heterotrophs is fascinating, but if we're going to get at ways to tweak the way that bacteria metabolize nitrate and phosphate ... remember pjf's thread-starting post? ... we're going to need to look at some of the specific chemical pathways. Enter Lithotrophs ...

Lithotroph
A lithotroph is an organism which uses an inorganic substrate (usually of mineral origin) for use in biosynthesis, or aerobic or anaerobic respiration. The term "Lithotroph" is created from the terms 'lithos' (rock) and 'troph' (consumer). It literally is the "eaters of rock." Lithotrophs participate in many geological processes, such as the weathering of parent material (bedrock) to form soil, as well as biogeochemical cycling of sulfur, nitrogen, and other elements.

For more background reading, see here (please note that this one is not specifically referenced):
http://en.wikipedia.org/wiki/Lithotroph


Some lithotrophic bacteria and their specific pathways ...
Iron bacteria oxidize ferrous iron (Fe2+) into ferric iron (Fe3+) ;
Nitrifying bacteria oxidize ammonia into nitrite or, nitrite into nitrate;
Sulfur bacteria oxidize sulfide into sulfur or, subsequently, sulfur into sulfate. They also can grow on a number of other reduced sulfur compounds (e. g. thiosulfate, thionates, polysulfides, sulfite).


The varieties of lithotrophs that are of most use to marine aquarists include:

Chemolithotrophs
Use inorganic compounds for aerobic or anaerobic respiration. The energy produced by the oxidation of these compounds is enough for ATP production. Some of electrons derived from the inorganic donors also need to be chanelled into biosynthesis.

Photolithotrophs
Use light as energy source. These bacteria are photosynthetic. Photolithotrophic bacteria are found in the purple bacteria (Chromatiaceae), green bacteria (Chlorobiaceae and Chloroflexaceae) and Cyanobacteria. The electrons obtained from the electron donors (purple and green bacteria oxidize sulfide, sulfur, sulfite, iron or hydrogen; Cyanobacteria extract reducing equivalents from water, i. e. oxidise water to oxygen) are not used for ATP production (as long as there is light); they are used in biosynthetic reactions. Some photolithotrophs shift over to chemolithotropic metabolism in the dark.


Some of the more interesting lithotrophic bacteria and their pathways include ... Thiobacillus denitrificans which is one of many known sulfur bacteria oxidizing reduced sulfur compounds with nitrate instead of oxygen ... and ... Anammox bacteria which oxidise ammonia with nitrite as electron acceptor to produce nitrogen gas.


JMO ... HTH

[mesocosm]

Greetings All !


While all this definitional stuff is arguably necessary if we're going to speak meaningfully about the bacteria-driven biogeochemical stuff, it's hardly satisfying, and at this point ... arguably useless.

Happily, auckreef asked the really good question ...

Originally posted by auckreef
... how this will affect the aquarium?

Keeping in mind that this is JMO (and my previous Starbuks disclaimer) ... I happen to believe that the bacteria guild (there may be hundreds of different strains at work) is the single most important "factor" in the stability of marine aquaria. If a simple combination of readily available (... and cheap! ...) carbon sources & elements can be identified that functions to enhance reduction of various nitrogen and phosphorous compounds (without the need for synthetic resins and/or expense technology toys) ... wouldn't that be a really good thing for all of us?

Additionally, what if it turns out that corals, and their filter-feeding allies (like Gorgonians), not only like eating bacteria (BTW, there's lots of evidence for this, although some corals prefer sunbathing) ... but that they also benefit significantly from the metabolites that are generated by the bacteria living on their surface and immediate environment (holobiont)? If it turns out to be functional and safe (definitely an issue in the dosing of vodka and/or sugar in an uninformed, casual, or haphazrd way) wouldn't a simple, inexpensive combination of carbon sources & elements be a really good thing for the "hobby" in general?

What I'm fumbling around trying to say is this ... dosing carbon sources & elements has the potential to allow us to do things (in terms of simultaneous nutrient reduction and feeding) that no technological toy, mechanical upgrade, or synthetic resin can do. I do not assert the necessity of such a strategy ... the demonstrations of awesome mastery of the "minimalist" concept ecosystem managers speak for themselves. I'm saying that anything which is both safe and effective is a legitimate addition to the husbandry toolbox of reefkeepers everywhere.



JMO ... let the beatings begin.

[mesocosm]

Greetings All !

Originally posted by wilsonh
... but would indicate that autotrophs can be a lot more useful than heterotrophs, assuming they got their facts right. Any comments?

Fair enough ...

Nitrifying bacteria are chemoautotrophic bacteria that grow at the expense of inorganic nitrogen compounds. Many species of nitrifying bacteria have complex internal membrane systems that are the location for key enzymes in nitrification: ammonia monooxygenase which oxidizes ammonia to hydroxylamine, and nitrite oxidase, which oxidizes nitrite to nitrate.

http://en.wikipedia.org/wiki/Nitrifying_bacteria

The point that nitrifying bacteria such as Nitrosomonas, Nitrobacter, and Nitrospira are chemoautotrophs, and therefore legitimately classified with "autotrophs" ...

... is well made.

Apologies if I've contributed to any confusion with my clumsy lack of distinction between autotrophs (in general), photoautotrophs, and chemoautotrophs. I have a mental bias in that I think of autotrophic bacteria as being primarily photosynthetic (photolithotrophs). I think of the behavior of nitrifying bacteria as lithotrophic ... which the general useage allows (both academic and common) ... but the point that they might be more technically (better) defined as chemolithoautotrophs is very well taken.

Please don't be put off by these definitions, folks.
The distinctions are important ...


JMO

[Boomer]

Thanks again Mr. Bacteria