[DIYbio] Re: Hacking yeast to produce high CO2 / low ethanol


Metabolic modelling is one of my favourite hobbies (yes, I'm a weirdo) but even I would suggest you bite the bullet and carbonate the drink with external CO2. There are numerous industrial solutions for doing this and all the big breweries use them. Producing large amounts of CO2 and only that with yeast would be a very complex task as you need to mess with some of the most fundamental pathways of yeast metabolism.

"So then the question is: Is it possible to denature/prevent the enzyme responsible for converting Pyruvate into Acetadehyde + CO2, and rather have the activity redirect itself towards the mitochondria? Or is Acetyl-COA critical for mitochondrial functioning?"

As Skyler says, this is the switch between anaerobic and aerobic energy production. If there is oxygen present, then yeast will prefer using the mitochondria as it is more efficient. Without oxygen, anaerobic fermentation will take place and yeast will produce ethanol via acetaldehyde. So the only way you could operate the mitochondria constantly is to provide a steady supply of oxygen to your culture. This will lead to numerous problems.

To answer your second question, Acetyl-CoA is absolutely critical for metabolic function. Luckily, because its so important there are numerous ways of generating it. Glucose, fatty acids, amino acids, other things can all be channeled into Acetyl-CoA production. I don't know by heart what yeast likes to do, but I guess in a high oxygen, high glucose environment it will get it from the krebs cycle via citrate mostly, whereas in low oxygen via the pyruvate dehydrogenase complex. So you can probably knock out pyruvate dehydrogenase and still live with high oxygen, but your glucose uptake (and therefore growth) will be somewhat lower.

TL;DR: just carbonate your brew with external CO2, engineering yeast for it is a faff.

On Friday, 3 August 2018 07:09:24 UTC+1, Bryan Hugill wrote:
Hi there everyone - has anyone over here playing or be willing to play with the idea of hacking the biological pathway in yeast (Saccharomyces cerevisiae) to produce high CO2 and low ethanol? If yes, I'd very much like to talk to you. Cheers! Bryan

-- You received this message because you are subscribed to the Google Groups DIYbio group. To post to this group, send email to diybio@googlegroups.com. To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com. For more options, visit this group at https://groups.google.com/d/forum/diybio?hl=en
Learn more at www.diybio.org
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To unsubscribe from this group and stop receiving emails from it, send an email to diybio+unsubscribe@googlegroups.com.
To post to this group, send email to diybio@googlegroups.com.
Visit this group at https://groups.google.com/group/diybio.
To view this discussion on the web visit https://groups.google.com/d/msgid/diybio/2e062e12-ca23-49b1-8548-4d9309dca7e1%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • RSS


Post a Comment