A protein-rich cookie made from plastic and agricultural waste could help solve two serious problems facing future generations, according to a team presenting results from their NASA-funded project at the Fall Meeting of the American Chemical Society.
Plastic waste poses an ongoing environmental hazard and public health concern, despite efforts to reuse and recycle what we can.
Meanwhile, a need to feed growing populations – as well as a potential demand to feed “off-world” colonists exploring the Moon and beyond – presents challenges for future technology.
“Global food demand is expected to rise 35–56% by the year 2050, and about 30% of the world population will be at risk of hunger in the future,” says Lahiru Jayakody, an applied microbiologist from Southern Illinois University Carbondale in the US.
“The way to address that, I believe, is by using microbes.”
Jayakody and his fellow researchers genetically reprogrammed several yeast species to turn a soup of degraded polyethylene terephthalate (PET), discarded corn stalks, and other organic materials into something not only digestible by humans but potentially tasty.
A strain of Saccharomyces cerevisiae was tweaked to produce the flavoring agent vanillin from ferulic acid. Similarly, a strain of Rhodosporidium toruloides was engineered to chew through ethylene glycol as a carbon source and churn out the vitamin A precursor β-carotene.
By subjecting the mix of waste materials to a process that reduced them to a form that could be easily digested by the microbes, the researchers found they could create a mash of proteins and fats that were theoretically edible. All they had to do then was add some starch, fiber, and a touch of sweetener, and press out a bite-sized snack.
To make it fancy, they squeezed the mix through a 3D printer to make a branded micro-symbol, µ. Short for µBites or “micro-bites.”
While the team has to wait for approval to consume their baked goods, there’s no reason why the cookies wouldn’t be perfectly safe to eat despite being made using inedible plastic polymers.
“We were trying to develop technologies for plastic upcycling to make more valuable products,” says Jayakody. “We thought, why not focus on making food? Because plastic is carbon and food is carbon.”
The idea of employing microbes to transform waste carbon into something useful is far from novel. For years, researchers have turned to biological solutions to rebuild plastic or agricultural waste into lucrative products like fuel or building materials.
While there is certainly a lot of plastic waste to exploit as a source of carbon, we’d still need economically competitive ways to collect it and transform it into something marketable.
Whether there’s even a market for plastic-based foods is also an open question.
Nonetheless, having a library of engineered microbes at the ready might be the very thing NASA needs to meet a variety of future challenges. Including ways to quickly and economically transform waste carbon into food.
This research was presented at the Fall Meeting of the American Chemical Society.
Source: ACS
