Yeast grow in bioreactorsMARTINA BUTORACBaker’s yeast (Saccharomyces cerevisiae) is used to produce much of the world’s biofuel through the fermentation of sugars and starches into ethanol. But at high concentrations, ethanol is toxic to yeast, as is the heat the microbes produce throughout fermentation. Researchers have discovered cellular mechanisms that can substantially improve yeast’s survival in the presence of heat and alcohol, according to two papers published today (October 2) in Science by separate groups of researchers. These new insights could pave the way for genetically engineering more hardy strains for biofuel production.
Each group independently identified a different process that confers substantially increased tolerance in yeast. “The findings are a little bit unexpected, because we thought it was a complex problem,” said Huimin Zhao, a metabolic engineer and synthetic biologist at the University of Illinois at Urbana-Champaign who was not involved in either study. “The solution turns out to be very simple.”
“They’re [doing] really good underpinning work,” said Jim McMillan, the chief engineer at the National Renewable Energy Laboratory’s National Bioenergy Center in Golden, Colorado, who also was not involved in the research. “We’ll see how much of it can be leveraged into practical outcomes.”
Increasing alcohol tolerance has been a long-term goal of metabolic engineers, according to MIT’s Gregory Stephanopoulos, a coauthor of the paper ...
