Carbon source for denitrifying bacteria

[Jörg Kokott]

Hi,

that's actually the problem with most organic acids like acetate, proprionate, or compounds like glycerole and sugars.

The occurence of N-fixing cyanobacteria usually correlates to N limitations, when macroalgae and symbiotic coral's growth is limited. As N-fixation is highly energy dependend these cyanobacteria aren't very competitive if N is available for those other photoautotrophic organism and quickly disappear after a nitrogen source has been added to the tank or the skimmer has been disconnected for a couple of days.

But there are those cyanobacteria strains which in some tanks are really hard to get rid of even if nitrogen is available, and these usually develop fine under addition of certain organics.

There are only few cases where ethanol led to cyanobacteria to develop in contrast to acetate or other organic carbon metabolites.

As coral foods the concentration of organic compounds should therefore be in the nanomole or even femtomole range to prevent cyanobacteria growth

 

[Navyblue]

As mentioned I am currently dosing sucrose, if I were to switch to rice wine or lactitol/xylitol solution, what are the consideration that need to be taken care of? I'd probably start from mass equivalent. What do you guys suggest? Or for experimental purpose, I should just keep dosing sucrose?

 

[Navyblue]

Anyone?

 

[Bomber]

Ohhh. Do they wave around more using ethanol?

Maybe, but they sure get along a lot better.

WAIT, this might be the secret to getting more corals to spawn!

 

[Randy Holmes-Farley]

What do you guys suggest?

I don't have any particular advice. IMO, this whole area is experimental, and I'd say that if you want to do it, just try it carefully and see what happens.

 

[tonylamas]

I don't know about the sugars, but I wouldn't use rice wine. I would be worried about the other organics that it would add. Vodka tends to be pretty pure, as liquors go. Everclear would probably be better.

 

[Jens Kallmeyer]

The things in common use for denaturing ethanol in the US now include methanol, methyl isobutyl ketone (4-methyl-2-pentanone), isopropanol, ethyl acetate, gasoline, and "aliphatic hydrocarbons".

Hi

A tiny bit of methanol would be fine, ethyl acetate as well, but the rest.....urgs. I would definetly NOT want to add gasoline or some "aliphatic hydrocarbons" in my tank.
Regarding the methanol, Deltec once made a solution for their nitrate filter that contained some methanol. These filters worked quite well, however there were cases where an overdose caused massive fishkills. In microbiology there are several carbon source mixtures that contain methanol, however in rather small amounts (single %).
Regarding the issue "Vodka is hard to get, what else to choose?", here in Germany many people have shifted to plain grain spirit (called "Doppelkorn" in Germany). As long as it is a plain and clear spirit, it really doesn't matter. Everything that has some additional flavour or colour to it, like Wiskey, I would be reluctant to use. I once ran out of Vodka over the weekend and the stuff from the gas station was way to expensive so I used Italian Grappa. My heart was bleeding but the tank ran just fine on it.


Cheers

Jens

 

[Navyblue]

Hi Jens,

Looks like you have been dosing your tank too. Care to share about your experience? It would be great if you talk about your observation, effect, dosage and etc.

Thanks.

 

[Navyblue]

Btw just an update,

Day 1
15 ppm nitrate
pH 8.1

Day 1-6
6 ml saturated sucrose solution

Day 6
0 ppm nitrate
pH 8.2

Day 6-15
3 ml saturated sucrose solution

Day 16
0 ppm nitrate
pH 8.3

Day 16 onwards
1.5 ml saturated sucrose solution

I am reducing the dosage to find out what is the minimum amount needed by the tank, and also monitoring if there is any lowering of pH.

 

[Jens Kallmeyer]

Hi Jens,

Looks like you have been dosing your tank too. Care to share about your experience? It would be great if you talk about your observation, effect, dosage and etc.

Thanks.

Hi

Sorry for not answering a bit sooner, but I am extremely busy at the moment.

My ethanol experiences in a nutshell:
Started in December 2003, as I got the initial article from Jörg Kokott and Michael Mrutzek before it was actually published. My tank has ca. 900 L gross, 700 L net volume. Started with 1 ml Vodka, increased in 1 ml steps every 4 to 5 days, reached ca. 15 ml. Nutrients went down but not to zero, but this wasn't my intention anyways. My skimmer produces black slime that defies any description. Being in the Oceanography business since a few years I know how bad rotten marine life can smell but this stuff tops everything.
For the last half year or so I dose the Carbon source with a peristaltic pump 4 times a day. I write carbon source as I have shifted a bit from pure Vodka to a mix containing 4 parts Vodka and 1 part concentrated Vinegar (here in Germany we call it Vinegar Essence, contains 25% Acetic acid).
I keep a number of azooxanthellate corals, so I have to feed fine food frequently in quite huge amounts, morover I am a great fan of fat and happy fishes. Therefore I feed 7 times a day with a variety of frozen food and a home made suspension food that contains huge amounts of fat and amino acids. Through the food I add about 25 ml of a concentrated amino acid solution to my tank.
Pictures of my tank can be found here

www.aquabilderbuch.de/JensKallmeyer

The only drawback that I noticed was the tendency to yellow water. Therefore I added ozone to the skimmer, but only an extremely low dose, about 10 mg/h. Since then the water is crystal clear but nitrate levels came creepig up again, reaching 20 ppm. It took almost 4 months to bring these levels back down to 10 ppm. Apparently the ozone caused a massive shift in the microbial community structure due to the changes in redox conditions.

Now that the tank is back on track it runs fine, I can feed as much as I want, don't have to worry too much about water parameters, and the corals look healthy.

Cheers

Jens

 

[Navyblue]

Nice tank that you have Jens.

Thanks for sharing the information, no problem for the delay.

What is your reason of mixing vodka with vinegar? Are you expecting any to get acetic acetate? Or you just want to dose acetic acid?

By the way, any one has any information on the composition of vodka? What is it in there other than the 40% v/v of ethanol? Or pretty much there is nothing else to any significant amount?

By the way, I noticed that my yellow sarcophyton has turned brown significantly. I will probably switch to other carbon source after this week of 1.5 ml per day.

 

[Jens Kallmeyer]

Nice tank that you have Jens.

Thanks

What is your reason of mixing vodka with vinegar? Are you expecting any to get acetic acetate? Or you just want to dose acetic acid?

The reason was that I had the impression that only one single carbon source does not cater for the large variety of heterotrophs that are living in the tank but only those that do best on ethanol. By adding a different carbon source I try to broaden the spectrum. Not that 2 carbon sources are state of the art, nature is far more complicated than this, but its better than just one.

By the way, any one has any information on the composition of vodka? What is it in there other than the 40% v/v of ethanol? Or pretty much there is nothing else to any significant amount?

The remaining 60% are basically water. Nothing to worry about.

By the way, I noticed that my yellow sarcophyton has turned brown significantly. I will probably switch to other carbon source after this week of 1.5 ml per day.

I think Jörg Kokott has written something about sugar additions and the effects on zooxanthellae density, check earlier in this thread.

Cheers

Jens

 

[Navyblue]

I think I have decided my alternative carbon source to be xylitol, which is basically a straight chain 5 carbon compound with an alcohol group on each carbon, as this is the purest of carbon that I can get.

 

[Jens Kallmeyer]

I think I have decided my alternative carbon source to be xylitol, which is basically a straight chain 5 carbon compound with an alcohol group on each carbon, as this is the purest of carbon that I can get.

Sounds funky, please keep us posted on the results

I stick to Vodka and Vinegar

Jens

 

[Navyblue]

Sounds funky, please keep us posted on the results

I stick to Vodka and Vinegar

Jens

Sure. I am probably the most excited one .

And I also suppose that bigger molecules can end up with more varieties of intermediate chemical, in order to feed the variety of bacteria as you've mentioned. But the downside is they are all the same alcohol group, so I'm not sure whether it will help

But I do not know whether is it a good choice as I don't know how long can I have access to xylitol. However, I guess half a liter of xylitol solution that I have just prepared could probably last a year or so.

 

[daveandcole]

denitrifying bacteria cant use carbonate as carbon

denitrifying bacteria cant use carbonate as carbon

source. The denitrifying bacteria need a reduced version of carbonate.
How can the bacteria extract any energy from co3? They need carbon compounds that contain hydrogen. The hydrogens are removed and depostited on the electron transport chain were no3 is waiting to be reduced to n2.

products from the oxidation of ch groups with no3 as the electron acceptor would be co2,n2,h20

In this reaction sugar(sucrose,glucose) are the electron donors no3 is the electron acceptor.

Anyone care to calculate the free energy in this reaction?

 

[Randy Holmes-Farley]

In this reaction sugar(sucrose,glucose) are the electron donors no3 is the electron acceptor.

Anyone care to calculate the free energy in this reaction?


In this thread from the early days of the reef chemistry forum, Tatu gives some energy data:

http://reefcentral.com/forums/showthread.php?s=&threadid=52872

 

[Navyblue]

Just another update...

Day 1
15 ppm nitrate
pH 8.1

Day 1-6
6 ml saturated sucrose solution

Day 6
0 ppm nitrate
pH 8.2

Day 6-15
3 ml saturated sucrose solution

Day 16
0 ppm nitrate
pH 8.3

Day 16-17
1.5 ml saturated sucrose solution

Day 18-24
1.5 ml xylitol solution (Except for day 20 that I forgot )

Day 24
0 ppm nitrate
pH 8.5 (dripping kalkwasser, and a little too fast)

Xylitol solution is made by dissolving 300 g of xylitol in 400 ml of tap water.

It seems that the skimmate isn't that much anymore. But probably still more tham when not dosing.

 

[Randy Holmes-Farley]

Have you monitored phosphate during this period?

 

[Navyblue]

Nope, pardon my laziness

Btw, as I do not have any algae problems (just some diatoms during start up and minor cyano problem after that), can I safely say that I have very low to no phosphate in water?