[mana]

hi all
I have read this amazing paper entitled : Enhanced ethanol production via electrostatically accelerated fermentation of glucose using saccharomyces cerevisiae.

My students and I have been trying to produce ethanol from D-glucose with different protocols many times, but our efforts have not been successful yet. We have tried the protocol mentioned in your interesting paper with some changes due to our lack of facilities, and we didn’t achieve ethanol. A picture of our procedure has been attached.

In this condition, 20 grams of D- glucose was dissolved in 50 ml of distilled water, and 1 gram of bakery yeast was added to the solution, we put a carbon electrode connected to positive current and another carbon electrode which was stuck to the beaker wall connected to negative current (proposed by chat GPT) in the circuit, the voltage was set on 15.6 v and the reaction was kept on a radiator which temperature was about 33^oC for 24 hours, and the beaker was closed by using parafilm strip.  After this time we tried to measure the alcohol percentage with an alcoholmeter, and it showed nothing, we tried Jones reagent to check and it didn’t show any green color either, again 1 gram of fresh yeast was added to this solution and the reaction was kept in mentioned situation but it didn’t change the results.

I know our procedure is very different from what has mentioned in the paper, but unfortunately, we can’t provide the negative electrode and nitrogen gas and some other criteria as mentioned in the paper. I would be very grateful if you could tell us what we can do with our limitations to use this procedure and achieve ethanol.
thank you in advance for your help

[Hunter2]

First check, did you get any alcohol, if you dont use current?
What kind of bakery yeast did you use? Bakery yeast is normally  used to make bread. Not for production of alcohol. Better is get brewers yeast or nutritional yeast.

[mana]

First check, did you get any alcohol, if you dont use current?

no I didn't get any alcohol, and yes used current

[mana]

and this is the picture of the situation that has mentioned in the paper

[Hunter2]

First check, did you get any alcohol, if you dont use current?

no I didn't get any alcohol, and yes used current

Why do you think to get alcohol with current, if you dont get it without.
The reaction has to run without first. If this works, then you can accelarate with current.

[Borek]

"Electrostatic" means no current, just an electric field.

20 g of glucose per 50 mL of water sounds way too high, that's not what the original paper used.

How do you check for the ethanol presence?

[Hunter2]

True. He set 15,6 V

Jones Reagent and a alcoholmeter was used to check for  Ethanol.

After this time we tried to measure the alcohol percentage with an alcoholmeter, and it showed nothing, we tried Jones reagent to check and it didn’t show any green color either, again 1 gram of fresh yeast was added to this solution and the reaction was kept in mentioned situation but it didn’t change the results.

[mana]

First check, did you get any alcohol, if you dont use current?

no I didn't get any alcohol, and yes used current

Why do you think to get alcohol with current, if you dont get it without.
The reaction has to run without first. If this works, then you can accelerate with current.

yes you are right, I haven't thought about this, I have tested this reaction without electric field many times with different additives such as PBS buffer, yeast extract, ammonium sulfate or different amounts of glucose and yeast but in all cases we didn't achieved ethanol, it's better to say we achieved acetic acid instead, because the reaction mixture smelled like vinegar, I don't know, but I assume that this is because oxygen presence in our mixture reaction, and unfortunately we can't omit it because we don't have nitrogen gas or any other inert gases to inject to reaction mixture for oxygen removing, is there any way in your point of view to solve this problem, for example is there any yeast which can produce alcohol even in presence of oxygen (instead of saccharomyces cerevisiae) or etc.

[Hunter2]

I think it's still the yeast, what is not working.
My self I made honey wine Mead, by using brewers yeast and honey and got real good result.
The beer brewers and Whiskey makers, also dont use nitrogen.
Also your temperature is to high with 33 °C
For beer normally 15-20 °C for Wine 18- 25 °C
Above 30 °C the yeast dies.

[Corribus]

You can find a number of DIY solutions to creating anaerobic chambers via google search. They range from the sophisticated to the rudimentary - as simple as a jar with a burning candle. They aren't going to be perfect but even moderate depletion of headspace oxygen can make a difference in an oxygen-sensitive process.

[Borek]

Google for fermentation lock.