More on Genetically Modified Yeast: A Reader Responds

A mapped human gene

Written by Roger Burns

Hi Ken,

I read your blog referenced in the AHA TechTalk and found it amusing, and informative. The one thing that was not mentioned in detail, although you commented on it, was what *exactly* is GM yeast? Or, more specifically, what are geneticists doing to modify it? That might be some followup information worth researching.

Here are a few things that I would consider “bad” ideas. I, like you stated, am not against or for any science. Science is generally neutral. How it’s used is where the ethics come in. Humanity has a long history of pushing Nature to do our bidding. Sometimes it works out well: domesticated animals; sometimes not: killer bees.

Considering that Monsanto builds in a gene to not allow grains to germinate, the so-called Terminator Gene, I would wonder if they were also considering that for GM Yeast. It’s been known for some time that you can generally culture almost any yeast strain from the dregs of a bottle, unless it has been severely filtered, pasteurized, chemicalized, etc. Some old Belgian breweries had one strain for fermentation, and a different one for bottling. It had an effect that reculturing from the dregs would not get you their in-house strain. That was before modern cultivation of yeast strains, and the craft beer world seems a bit more open now to that sort of sharing. Unless you are AB/Inbev or Molson/Coors, etc. They are more cut-throat in the competition level with each other and smaller breweries (have you seen Beer Wars?). So, if they could insert a Terminator Gene in some proprietary line of yeast, then they could control specific strains and not worry about competitors getting them.

Another example of bad. The guy who resurrected the 45 million year old yeast from the gut of an insect trapped in amber was a geneticist that went to great lengths to try and patent the yeast, it’s genetic makeup, and refer to brewers who might try to reculture it from a bottle as “unscrupulous brewers.” Patent and trademarks laws are weird. I thought you could only patent a process, not a living organism, or something that you discovered “made by nature.” But we’ll see on that one. Someone who goes to those lengths, and purports to test competitor’s beers for “his” yeast strain might be interested in GM’ing the equivalent of a “serial number” into a yeast. Imagine if each brewing house could not only use their house yeast, but also sue anyone who might also use it? It would definitely dampen the feeling of camaraderie in the craft/home brewing sphere. But in this sue-happy world, I could see some large corporation doing that. (Again, Beer Wars reference to when AB/Inbev sues Dogfish Head brewery for using the terms “punkin’ ale” and “chicory stout”).

Where most people are concerned about GM’ing is not the active breeding of similar strains of whatever plant or animal, but the introduction of novel material, such as the phosphorescent jellyfish gene that has been used in GM animals to be able to track genes. Ever seen the glow-in-the-dark pigs? Imagine if you are a vegetarian (if you are, then you don’t need much imagination) or have a specific allergy and then ingest a beer with that allergen or meat product. At the least, distasteful due to personal choice. At worst, a deadly reaction.

So, those are some fears. However, the benefits could also be recognized. Having new, or novel flavors, or more control over flavors you alluded to. Remove the sulfurous day-after-beer-drinking-gas might make a lot of wives happy. Getting a strain to properly ingest certain polysaccharides, or further attenuate beyond their natural capacity might be a good thing.

Who knows. Someone might also come up with a yeast that emits certain flavorings, like lemon or blueberry. The “natural” release of these compounds could negate the use of certain chemicals in beer. There’s a lot of fear about preservatives in the US. Some breweries pasteurize to improve shelf-life. Some remove the chemical compounds that cause skunking (thus allowing them to bottle in clear glass). If you could have a “natural” organism take care of that for you, isn’t the result better in some way?

Another thing to consider is that yeast that may be GM’ed for non-brewing related activity. There is a lot of use for yeast in fermentation of “excess material” for bio-fuels. Just because they make yeasts there that can synthesize wood proteins, etc, does not mean they will make it into a brewery. What about the oil eating organisms that clean up oil spills? Yeasts are really good little nano-nature, for the most part. Modern technology still doesn’t have anything on them. We are seeing that in the researching areas more and more. Why build a little engine when you can modify and existing organism (who hopefully does not mind) to do the things on the small scale that we simply cannot?


Roger Burns