Biofuels like ethanol could help us reduce our dependence on fossil fuels, but growing crops for ethanol involves using up huge swaths of valuable farmland. Now we might have a solution - thanks to some re-engineered yeast.
Ethanol and other biofuels face a number of hurdles in becoming a viable alternative energy source, and one major problem is that we can only synthesize them from food crops and otherwise useful agricultural resources. The goal is to make ethanol using only non-edible plants, which are known as cellulosic materials.
The problem is that the yeast we use to transform corn sugars into ethanol doesn't really work with cellulose-based sugars, making any such conversion a hideously inefficient process. But Jonathan Galazka and his team of researchers at UC Berkeley might have figured out a way around this. They found a fungus, N. crassa, that does grow well on cellulosic sugars, and then they isolated the enzymes it uses to harvest the cellulose sugar.
Once they had identified the mechanisms that transport and convert sugar from the cellulose to the fungus, they removed this system and adapted it to the biochemistry of the yeast S. cerevisiae, the yeast most commonly used in the biofuels industry. The engineered yeast worked perfectly, successfully growing on the cellulosic sugars and opening up the possibility of harvesting large-scale ethanol supplies from these cellulose-based materials.