Let's Talk About Heterotrophic Bacteria for Controlling DOC, Nitrogen, and Phosphates

[sixty_reefer]

Hey... I have another dumb question. Do the heterotrophic bacteria uptake free carbon, nitrogen, and phosphate separately or is the carbon, N, & P contained in DOC that the bacteria then uptake... or am I just so far off that it really is a dumb question?

there isn’t dumb question in our hobby just dumb answers.

Some abbreviation properly used.

Doc = dissolved organic carbon
DIN = Dissolved inorganic nutrients
DON = Dissolved organic nutrients
P = Phosphorus
N = Nitrogen
C = Doc = Dissolved organic carbon
No3 = Nitrates
Po4 = Phosphates


One way to understand how some heterotrophic organisms utilise only Doc and DIN is to look at carbon dosing, we add Doc in a way to lower the DIN pollutants they are utilising all the nutrients from the water column other heterotrophic organisms will be able to get DOC and DON from Organic Matter.

a interesting note here is that organisms that assimilate Doc and DON will release DIN into the water column as they perish/die

Other interesting note is that most heterotrophic organism will be releasing DIN and DON into the water column trough waste that is den assimilated by heterotrophic bacteria if this bacteria isn’t actively removed via protein skimmer DIN will become available again in the system or stored as detritus.

A lot of confusion is created as many believe that DON and DIN are the same thing, DON is the first phase of nutrients and this will be important building blocks for coral and algaes.
DON will be important Nutrients source for Autotrophic and Heterotrophic organisms and DIN are pollutants that will be exported from our systems by other heterotrophic and autotrophic organisms through assimilation or chemical interactions.
DON is the preferred source of nutrients for autotrophic organisms like coral and algae, and DIN can be reduced if a good amount of coral and algae is present in a system reducing the amount of DIN as most DON have been assimilate by algae and coral. This means that algae beds won’t necessarily reduce DIN as they will be removing DON before it can be converted to DIN.

if someone were to read the study by redfield and understand it, something that could be noticed would be that the study only mentions DON that is C N and P.
C is Doc
N is nitrogen and part of DON
P is phosphorus and part of DON.

it down mention of DIN in the study
No3 is nitrate and part of DIN
Po4 is phosphates and part of

 

[chema]

A lot of confusion is created as many believe that DON and DIN is the same thing. DON will be important Nutrients source for Autotrophic and Heterotrophic organisms and DIN are pollutants that will be important for heterotrophic and autotrophic organisms.

As explained here I do not see the difference between DON and DIN, except for the arbitrary use of the terms nutrients and pollutants. What may be a pollutant for a certain organism may be a nutrient source for another.

In the following paragraph a difference between DON and DIN is stablished on the basis of a differential use by coral, and algae. However it is an oversimplification. Corals do not use dissolved sugars such as glucose (which is DON) because they use the one provided by zooxanthellae (sinthesized by photosynthetic means). Corals are not photosynthetic, the zooxanthellae they contain are.

Actually, the terms DON and DIN have a very reduced meaning in biochemical terms as sources of nutrients either for micro o macroorganisms.

 

[sixty_reefer]

As explained here I do not see the difference between DON and DIN, except for the arbitrary use of the terms nutrients and pollutants. What may be a pollutant for a certain organism may be a nutrient source for another.

I’ve Edit the post wend I realised I’ve wrote it wrong.

DON will also contain Carbon compounds and DIN won’t.
I agree is all part of a cycle that is very interesting and confusing

In the following paragraph a difference between DON and DIN is stablished on the basis of a differential use by coral, and algae. However it is an oversimplification. Corals do not use dissolved sugars such as glucose (which is DON) because they use the one provided by zooxanthellae (sinthesized by photosynthetic means). Corals are not photosynthetic, the zooxanthellae they contain are.

they will become Doc and utilised by microbes, zooxanthellae will utilise nitrogen, phosphorus and N-Doc in our system and some DIN

Actually, the terms DON and DIN have a very reduced meaning in biochemical terms as sources of nutrients either for micro o macroorganisms.

 

[Randy Holmes-Farley]

Hey... I have another dumb question. Do the heterotrophic bacteria uptake free carbon, nitrogen, and phosphate separately or is the carbon, N, & P contained in DOC that the bacteria then uptake... or am I just so far off that it really is a dumb question?

Organic carbon will often contain N and P as well as carbon and other atoms. A protein or amino acid, for example, will contain N and C, and maybe P. A phospholipid will contain N and P and C.

Exactly what types of organics are being consumed will determine whether any given organisms need additional N or P, or both, or may be acting as a source of inorganic N or P because it is already getting more than it needs.

As folks noted above, organic carbon dosing schemes typically add C and not N or P, thus skewing the bacterial processes to become net users of inorganic N and P.

 

[ReefGeezer]

Organic carbon will often contain N and P as well as carbon and other atoms. A protein or amino acid, for example, will contain N and C, and maybe P. A phospholipid will contain N and P and C.

Exactly what types of organics are being consumed will determine whether any given organisms need additional N or P, or both, or may be acting as a source of inorganic N or P because it is already getting more than it needs.

As folks noted above, organic carbon dosing schemes typically add C and not N or P, thus skewing the bacterial processes to become net users of inorganic N and P.

Thanks Randy. I always thought organic carbon dosing created organic compounds that the bacteria then used. This has been a source of my confusion for a while I think. So, more specifically, when carbon dosing, are the bacteria encouraged to grow using the carbon we add directly, along with inorganic N & P; or are organic compounds formed that contain carbon, N, & P that the bacteria then use; or are both processes possible? Sorry to be a pest, I'm beginning to believe I might be a little dense!

 

[ReefGeezer]

Carbon limitation is assured for heterotrophs. Food is the wrong ratio of elements.

Thanks for the information Dan. So, is the carbon limitation assurance caused by bacterial growth until it is limited by the available carbon, regardless of how much is input. And if you please, what do you mean by" Food is the wrong ratio of elements"?

Where ratios are actually important is when you want to minimize nitrate accumulation. By keeping the ratio of C:N in food at the appropriate level, you favor heterotrophic bacteria over the autotrophs. The reason being, a high food C:N ratio provides C for energy and all the N can go into biomass and not to NO3. Reefers do this when they carbon dose, though they don’t calculate the C:N ratio needed but find it empirically when they establish a maintenance dose.

This is one of the things I have worried about when carbon dosing. With a lot of the N going to biomass, does it limit the N available corals or are they included in your definition of biomass?

Again, thanks for the replies. I've already had a couple ah-ha moments.

 

[Koty]

The first thing I learned in microbiology is Ubiquity and the second is Diversity. Thus, without any addition of bottled stuff, the right bacteria will always find their way into our tanks and populate the many niches within. Probably spitting into the tank with our bacteria-infested mouth will be enough (but also unnecessary). for every combination of (extreme) environmental conditions and (crazy) type of energy source, there will be bacteria that will be able to use it.
Bacterial growth will be inhibited by depletion of a food source or accumulation of waste that may change the environment and pave the way to a different one.

 

[Randy Holmes-Farley]

Thanks Randy. I always thought organic carbon dosing created organic compounds that the bacteria then used. This has been a source of my confusion for a while I think. So, more specifically, when carbon dosing, are the bacteria encouraged to grow using the carbon we add directly, along with inorganic N & P; or are organic compounds formed that contain carbon, N, & P that the bacteria then use; or are both processes possible? Sorry to be a pest, I'm beginning to believe I might be a little dense!

Bacteria consume and metabolize the ethanol or acetic acid to get energy, producing CO2 in the process. Same as we would if we consume them.

As they grow, they will build lots of biomolecules such as proteins. To do that they also need a source of N and P (and a few others, such as sulfur). Some of the C in those molecules may come from the organic directly and some from CO2.

They will also shed biomolecules to the environment, and those will contain C and often N and P, which other organisms may consume (or they may eat the whole living or dead bacteria).

 

[ReefGeezer]

Bacteria consume and metabolize the ethanol or acetic acid to get energy, producing CO2 in the process. Same as we would if we consume them.

As they grow, they will build lots of biomolecules such as proteins. To do that they also need a source of N and P (and a few others, such as sulfur). Some of the C in those molecules may come from the organic directly and some from CO2.

They will also shed biomolecules to the environment, and those will contain C and often N and P, which other organisms may consume (or they may eat the whole living or dead bacteria).

Thanks Randy. I am beginning to understand.

 

[ReefGeezer]

The first thing I learned in microbiology is Ubiquity and the second is Diversity. Thus, without any addition of bottled stuff, the right bacteria will always find their way into our tanks and populate the many niches within. Probably spitting into the tank with our bacteria-infested mouth will be enough (but also unnecessary). for every combination of (extreme) environmental conditions and (crazy) type of energy source, there will be bacteria that will be able to use it.
Bacterial growth will be inhibited by depletion of a food source or accumulation of waste that may change the environment and pave the way to a different one.

I have often wondered about "ubiquity" (not that I knew what it was called 15 minutes ago) vs. the popularity of bottled bacteria. Could strains of bacteria be present on or around reefs that aren't present in say Kansas?

 

[Dan_P]

Thanks for the information Dan. So, is the carbon limitation assurance caused by bacterial growth until it is limited by the available carbon, regardless of how much is input. And if you please, what do you mean by" Food is the wrong ratio of elements"?

Let’s start with the notion that food has the wrong ratio of elements, stoichiometry.

Food is used for energy and to make biomass (more bacteria cells, longer GHA, bigger coral, bigger fish). If food were consumed only to make biomass, there wouldn’t be much waste (approximately), but in reality, much of the carbon (50-90%) in food is used to make energy, the carbon being oxidized to CO2. All the other elements, most importantly N and P, are waste and eliminated from the cell. This is why aquaria are carbon limited and why nitrate and phosphate accumulate unless removed from the system (exported). The food we add has the wrong ratio of elements for a zero accumulation of nitrate and phosphate system. No matter how much food we add, nitrate and phosphate will accumulate

This is one of the things I have worried about when carbon dosing. With a lot of the N going to biomass, does it limit the N available corals or are they included in your definition of biomass?

Again, thanks for the replies. I've already had a couple ah-ha moments.

Coral are part of the biomass in an aquarium. Carbon dosing to increase bacteria biomass might result in competition for nitrogen but unless the nitrogen approaches zero ppm, carbon dosing does not seem to harm coral (at least that is my impression I get from the forums)

 

[ReefGeezer]

Let’s start with the notion that food has the wrong ratio of elements, stoichiometry...

Wow. I really didn't know that so much of the carbon was used for energy. Neither did I understand how N & P binding was impacted by how the carbon was being used by the cells. I saw it as a very linear process like maybe: carbon + N + P > bound in bacteria biomass > export. Thanks Dan.

 

[Dan_P]

Wow. I really didn't know that so much of the carbon was used for energy. Neither did I understand how N & P binding was impacted by how the carbon was being used by the cells. I saw it as a very linear process like maybe: carbon + N + P > bound in bacteria biomass > export. Thanks Dan.

Yes, quite an eye opener. I expect other forum members will jump in to correct, clarify and add to this, which will be cool.

Dan

 

[ReefGeezer]

there isn’t dumb question in our hobby just dumb answers.

Some abbreviation properly used...

DOC as I was using it was intended to describe dissolved organic "compounds". This reflected how I believed the process to work. I thought the bacteria were using organic compounds not just carbon. Now that I've been schooled a little on how the bacteria's processes for using carbon work, I can see the value of discussing dissolved organic carbon. I suppose that is as opposed to something like CO2?

Yes, quite an eye opener. I expect other forum members will jump in to correct, clarify and add to this, which will be cool.

I hope so Dan. This discussion has already given me much to think about.

 

[Randy Holmes-Farley]

Yes, quite an eye opener. I expect other forum members will jump in to correct, clarify and add to this, which will be cool.

Dan

To add some color to that correct statement that typical natural foods for heterotrophs always have a lot more N and P than needed, the same thing happens in people (and all animals).

Folks with kidney Disease who cannot appropriately excrete the excess N and P they must consume to get sufficient energy have to look to other ways to keep these from building up to excessive levels in the blood. Phosphate is especially problematic, and such patients cannot get to a healthy balance from any sort of reasonable diet. Thus they take oral phosphate binders to bind the phosphate that breaks free from digesting food before it can be absorbed.

These phosphate binding drugs include many familiar to reefers: lanthanum, calcium, aluminum, and my polymer drugs sevelamer carbonate and sevelamer hydrochloride.

 

[ReefGeezer]

I’m super interested as well. Personally, Ive come to believe that the microbiome is the most important element to a healthy reef aquarium.

I am coming to that realization, but can't help including other organisms in my thinking process because they affect how the microbiome's use of carbon and subsequent waste impacts the overall biome.

 

[melonheadorion]

its funny. lately ive had a few random questions of my own, where looking through the forums, there happens to be a new post asking about it. this is one of those that just came up for me 3 or 4 days ago, after getting 2 new sps frags.

just previous to that, my phosphates were at .13 or so, which isnt horrible, but wanted to be around a .03-.05 ish, so ive been using some rowa phos to get it down, added some chaeto to my refugium to help get it to a "better" number. for the last 2 days, i also used some of the tropic marin elimi np, which helped tremendously. now im at about a .03. right where i want to be. i know that the elimi np also affects nitrates, which is the second part of an issue i realized i have as of last night. normally, my nitrates were 13-15. last night, i find that they are at 40 or so. perhaps it was a testing error, but multiple tests showed the same thing. today, i did a 25-30% water change to get the nitrates to a better number. got it down to what looks to be 20ish. its an api test kit and a red sea test kit, so the quality of one, and the color coding of the other are definately not the best, or most accurate, but between the two, my guess is that its about 20, which again isnt horrible, but i would prefer to be 15 or less for the sake of these 2 new SPS.

this is where my question comes in, because i originally bought the elimi np to get phosphates down, on my old tank, and now that i needed it on my new tank, it worked out great. however, here i am with a imbalance of phosphate vs nitrate. obviously, there are many ways to reduce nitrate (one of them being WC), but i would also like to know more about the options with carbon dosing. from what ive read, and maybe im completely wrong, but it seems that carbon dosing should help eliminate nitrate as well. to help control my nitrate, would carbon dosing with the tropic marin bacto balance help with that, at the uneven numbers that i am at, or would it ultimately bottom out P for the sake of also lowering N or would it raise P for the sake of bringing it to a more acceptable ratio to N?
I guess i just dont understand how these bacterias, between the products of tropic marin work. one is for reducing P with a side effect of reducing N, but then there is the one that is somehow supposed to balance them out, but i dont know if using the bacto balance will do much else other than what elimi np already does.

this is the part that confuses me with the N / P stuff, and the technical terminaology makes it hard to understand for a dummy like myself

 

[Dan_P]

To add some color to that correct statement that typical natural foods for heterotrophs always have a lot more N and P than needed, the same thing happens in people (and all animals).

Folks with kidney Disease who cannot appropriately excrete the excess N and P they must consume to get sufficient energy have to look to other ways to keep these from building up to excessive levels in the blood. Phosphate is especially problematic, and such patients cannot get to a healthy balance from any sort of reasonable diet. Thus they take oral phosphate binders to bind the phosphate that breaks free from digesting food before it can be absorbed.

These phosphate binding drugs include many familiar to reefers: lanthanum, calcium, aluminum, and my polymer drugs sevelamer carbonate and sevelamer hydrochloride.

Ha! This is indeed interesting color.

 

[ReefGeezer]

Thanks to all who have contributed to the knowledge base so far... I have another question. It occurs to me because of the "Ubiquity" issue brought up by @Kota. So... If bacteria are everywhere, why is it that we are buying live rock and sand or bottled bacteria to "seed" it in our tanks. Is it that we are trying to establish a particular microbiome before nature can do it for us? Or could it be that some beneficial bacteria is effective for a while but is eventually out competed by faster growing strains? Or are we trying to control that which is really out of our hands? I've read some posts from at @AquaBiomics and @Hans-Werner discussing similar issues but I'm afraid they were a little over my head.

 

[Dan_P]

DOC as I was using it was intended to describe dissolved organic "compounds". This reflected how I believed the process to work. I thought the bacteria were using organic compounds not just carbon. Now that I've been schooled a little on how the bacteria's processes for using carbon work, I can see the value of discussing dissolved organic carbon. I suppose that is as opposed to something like CO2?

I hope so Dan. This discussion has already given me much to think about.

Cool. Looking forwards to others piling on with more to think about.