Simply put: the scientists took yeast – in this case saccharomyces cerevisiae (s.cerevisiae) and monitored it’s activity. Anyone who has brewed beer knows that – it, like any living organism, is unpredictable. Yeast can stall out, become sluggish, affecting the outcome of the brew. Here’s where sci-fi meets reality.
A genetically modified molecule called a phytochrome spys on the the nearby yeast cells. When reporting inactivity, scientists can have the phytochrome send out a beam of red light, turning the cell on again. A deeper red beam of light will turn it off again. Having this molecule fluoresce then reporting back, scientists can create a complex computer model of the yeast’s behavior. Each burst of light is tracked and accounted for through this feedback loop. Using this molecule and a computer, you can literally speed up and slow down fermentation.
Other than beer, what are the implications? Beyond beer fermentation, this molecule has implications in biofuel production, and antibiotic production. The process allows scientists to fine tune gene expression, controlling the quality and quantity of the final yield. [BBC]