A thought on CO2 production with yeast

Okay, jello is in the fridge setting. Mixed strawberry and orange! Heh.

Man, I can't even look at jello now without thinking of high TDS and OTS and visualizing fish trying to swim in that stuff.

That'll teach me to create analogies :rolleyes:

Roan
 
Well, peroxide should push the yeast into aerobic respiration, which is more efficient where CO generation is concerned. How much to use without killing the yeast but still having the desired effect is one good question to explore, and rate and technique of addition is another extremely important question. You don't want the culture oscillating between aerobic and anaerobic, nor do you want to kill it. I foresee interesting technical issues. Have fun, and do report back...
 
If my knowledge serves me right, Hydrogen Peroxide is a strong oxydizing agent and is used as a biocide. It works similar to bleach oxydizing any organic is gets in contact with. It works by forming monoatomic oxygen (O) as it breaks down. This monoatomic oxygen is highly agressive and will react with anything it can unless it can bind up with another monoatomic oxygen molecule to form O2. That is why it can be used to bleach hair, teeth and even skin. Put a drop of peroxide on your skin and rinse it off after a minute. You will see how it reacted with the melanin in your skin and whitened it. Don't worry your body will soon replace this and the white spot will go away. I don't think peroxide will do the trick in this instance but you are worth giving it a shot. To me it is the same as saying that adding a little bit of bleach to the yeast reactor will increase CO2 production. We all know that it does not happen.
 
Respiration with H2O2

I'm not sure that yeast use H2O2 for respiration. As was previously stated hydrogen peroxide when broken down forms water and O, not O2, which is a free radical and can cause the death of organisms which don't have the enzyme catalase to deal with this.If they don't then adding it could be at the expense of yeast because they have to ramp up catalase production to deal with it when they could use this energy for something else, aka making CO2 for you, and they would still have to ferment sugars which is self-inhibiting. Even though yeast have catalase I would be scared to add H2O2 because they may not be able to detoxify all of it. I'm very skeptical of this method but I hope you try it so we can see what happens, it would be great if it works.
 
This isn't going to be much of a controlled experiment, y'know :)

I am going to add the yeast and warm water to the mixture and run the tubing to a glass of water to use as a bubble counter.

Once gas production begins, I'm going to add 1/8 teaspoon of H2O2 and put the whole thing somewhere "safe" :D

1. My first goal is just to see if gas is still produced when H2O2 is added

2. If #1 is true, then is there more or less gas (jello is pretty "stable" so I should be able to get some sort of before and after measure)

3. If #1 is false, then I'd say that the H2O2 killed or interfered with the yeast and either scrap the idea or try again with a much lower amount

Complications from this could be: dead yeast, large gas build up resulting in a rupture of the bottle, jello all over the place

Is there any other type of gas that could be produced if these two are mixed? Meaning if I do get gas, will it be CO2 or something else?

Roan
 
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In low concentrations I would think that the yeast would be able to deal with the H202 especially since they have evolved a way to deal with this i.e the enzyme catalase, which turns H202 directly into O2 skipping the dangerous monoatomic O stage (not to say that some still wouldn't be formed.) Additionally the low cost of producing the enzyme catalase would, I think, be far offset by the greatly increased energy produced through aerobic respiration which produces much more energy then anaerobic respiration and skips that pesty by-product ethanol.
 
Well, you can have O2 evolved from the solution. Free radical O is highly reactive, it is quite "content" to partner with another of the same to make O2 and once the water is supersaturaed it will bubble out. Gas alone does not prove CO2.

Commercial peroxide solutions are pretty mild, but the damage/death line from free radical O is easy to cross.

A pH test on the water into which you tube the gas will give you a stong hint - just like your tank, bubble in CO2 and the pH falls. CO2 is far more soluble than O2, so you should get enough with any visible production to read a pH shift in a small vessel.
 
Nod, going to track it the same way I do my tanks. Going to set it up tonight, I'm a little wired to be tracking CO2 atm.

In freak zone atm because my best Goo obo gudgeon pair decided to lay their bloody eggs in the little hole my heater cable goes into. ARGH!

Why? I made them a lovely coconut hut. There's pipes, holes, hidey holes -- but noooooooooooooo they pick the heater!!!!

Sigh.

Roan
 
When the yeast enter fermentation from lack of oxygen, they take the glucose (which they get from the table sugar sucrose), and through some biochemical juggling turn it into 2 molecules of CO2 and 2 molecules of Ethanol (alcohol).

When O2 is present, the sugar is turned into, hmmmmmmmmm, I can't remember....:-). But it then enters the citric acid cycle where al lthat carbon is used to create biomolecules. Things like fattyacids, proteins, engine blocks, whatever. The point is that very little of the actual carbon (the table sugar you add) actually ends up as CO2.

You will get less CO2 production when oxygen is present.

Here is a situation you may be familiar with: When you set up a CO2 yeast bottle, there is a lag of several hours before bubbles appear. That lag is the yeast growing in the presence of the oxygen in the liquid. No gas is being produced, (except for very very (meaning no bubbles) small quantities that a carbon eating life form would respire).

Visible CO2 production doesn't occur until the oxygen runs out.

I hypothizize that your bioreactor would stop working or slow down for awhile after adding Oxygen, and I also hypothizize that I need a dictionary.
 
1HungryGoldfish said:
Here is a situation you may be familiar with: When you set up a CO2 yeast bottle, there is a lag of several hours before bubbles appear. That lag is the yeast growing in the presence of the oxygen in the liquid. No gas is being produced, (except for very very (meaning no bubbles) small quantities that a carbon eating life form would respire).
Click to expand...

Actually, no.

Not saying you're wrong with your hypothesis, but that the "lag" I get is usually less than 30 mins, not several hours.

Roan
 
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