Article: Ethanol Release Relieves Yeasts Stresses

Without any disrespect to the scientists involved, it seems pretty likely to me that ethanol production is at least partly related to controlling the yeast's environment and suppressing competing microbes. (Same with acid production in bacteria.)

Still, interesting read, thanks for posting.

 

Cool read man thanks!

 

Sounds very legit.

Thanks all. Interesting stuff.

 

Different scales of organization. They are talking about sub-cellular stuff, energetics of metabolism. You are talking community-level stuff, interactions with other organisms. Ethanol production contributes to improved metabolism (according to what I got out of the article), and fosters an environment in which yeast have adapted tolerance and others have not. If either one of those things weren't true, we probably wouldn't have much of a hobby!

You might even argue that ethanol production occurs so that yeast could manipulate brewers into perpetuating strains.

 

Yeah, I don't mean to question the explanation being put forward by the scientists, I am sure they are right in some sense. I was mostly reacting to this:

'Metabolizing a six-carbon molecule to a two-carbon molecule, rather than to carbon dioxide, means part of the energy and matter stored in glucose is lost. It makes no sense', says Matthias Heinemann, Professor of Molecular Systems Biology at the University of Groningen.

Imagine if a biologist said something like, "Birds use their wings to fly from place to place, but in fact it's much more energy-efficient to walk or hop. It makes no sense." It wouldn't be a totally idle point, since we've observed flightless birds on islands where there are no predators. (Observed them... and then promptly hunted them to extinction.) But it's also not a mystery why flight is a winning strategy for most birds, energy inefficiency notwithstanding. Similarly with yeast. It's not exactly a puzzler why yeast give up a little metabolic efficiency for the sake of killing their competitors.

In fact it wouldn't surprise me if scientists were ultimately to learn that the metabolic "safety valve" that the scientists identified is not a necessary feature of cellular metabolism but rather evolved in particular so that they would start excreting alcohol when they find themselves in particularly nutrient-rich environments. That's just speculation, but anyway I thought the way the scientists framed the puzzle was odd.