Octoberfest in Germany. Credit: senator86; Wikepedia, Creative Commons license

It’s September, which means Octoberfest season is almost here. Ever wonder what really makes those delicious brews?

I just came across this fun piece of science about the domestication of yeast microbes, those friendly little beasts that make lager beers for us.

The domestication of plants and livestock, a crucial development in human history, has been pretty well documented through the ages. Not known, however, is the history of microbe domestication, despite their importance for food and beverage production, and in modern times, for biofuels.

Luckily (I guess), the ability to map genome sequences means that the “family tree” of microbes can be mapped and the connection between the working-class brewmeisters and their free-range cousins can be established.

Lager beers date back to the 15th century and are brewed using the “allotetraploid hybrid” yeast, Saccharomyces pastorianus. In a new paper published in the Proceedings of the National Academy of Sciences, an international team of geneticists and biochemists report using genome sequencing to relate the domestic yeast to several related, wild species. They speculate that lager beers are the happy result of a change in the way now-domesticated yeast metabolizes sugar and sulfites.

They conclude, “This study shows that combining microbial ecology with comparative genomics facilitates the discovery and preservation of wild genetic stocks of domesticated microbes to trace their history, identify genetic changes, and suggest paths to further industrial improvement.”

I’ll drink to that! Prost!

See: “Microbe domestication and the identification of the wild genetic stock of lager-brewing yeast,” by Diego Libkind, et. al. Proceedings of the National Academy of Sciences (doi: 10.1073/pnas.1105430108)

Peter adds: “DIY brewing has had sustained popularity (estimates range from 0.5–1.5 million home brewers in any given year in the US, producing around 9 million six-packs). The new issue of Wired describes how low-cost DIY genome sequencing is starting to emerge among biohackers. It won’t be long before these trends collide with some genome-hacked yeast to make some super brews.”