Microbes Turn Greek Yogurt Waste into Biofuel

Researchers from Cornell University in the US and University of Tübingen in Germany have found a way to use bacteria to turn the leftover sugars and acids from Greek yogurt into molecules that could be used in biofuels or safe feedstock additives.

Waste whey from Greek yogurt production is made up mostly of lactose, fructose, and lactic acid. The researchers used bacteria to turn this mixture into an extract containing two more useful compounds: caproic acid and caprylic acid. Both of these compounds can be further processed into "drop-in" biofuels for jet fuel. The researchers first strung together two open-culture reactors. After seeding each reactor with previously studied microbes and having the acid whey as their carbon source, products such as caproic acid and caprylic acid could be continually extracted over a period of several months.

The next challenge will be to see what happens when the twin bioreactor system is boosted to pilot plant capacity.