Transforming Food Waste into High Quality, Fully Biodegradable Bioplastics

Luna Yu, a recent graduate from the Master of Environmental Science program at University of Toronto Scarborough teams up with a talented group of scientists and engineers — many of whom are U of T students or alum — to form Genecis. The company uses recent advancements in biotechnology, microbial engineering and machine learning to take food destined for landfill and convert it into high quality, fully biodegradable plastics.
Food waste is a significant environmental issue in North America, explains Yu. In the United States roughly 55 million tons of food is thrown away annually. Once that food hits landfill it generates methane, a greenhouse gas that’s 20 times more potent than carbon dioxide. In fact, it’s estimated that 34 per cent of methane emissions in the U.S. alone are caused by food waste.

Luna Yu said:
“We feel that by using synthetic biology create high quality products out of this organic waste in a cost-effective way – while also mitigating the effects of plastic pollution – is really the way of the future.”
Though only in her early 20s, this isn’t Yu’s first foray into entrepreneurship. She has more than six years’ experience, first at a start-up software company as an undergrad before moving to another start-up that converted restaurant food waste into biogas.

It was there that she met several talented engineers, learned about the microbiology of converting discarded food into other materials, and discovered a valuable lesson in the economics of re-using food waste.

Luna Yu said:
“Converting food waste into biogas is not only a time-consuming process, the end product is fairly low value.”
It was shortly after this experience that she connected with a fellow environmental science student in The Hub, U of T Scarborough’s entrepreneurial incubator, to figure out what else could be made from food waste.

Luna Yu said:
“We looked at different types of bio-rubbers and bio-chemicals before landing on PHAs. We felt it had the biggest market potential.”





A Reusable, Biodegradable form of Plastic


PHAs, or polyhydroxyalkanoates, are a type of polymer produced in nature by bacteria that have many benefits over other forms of bio-plastics. For one, it can be a thermoplastic, meaning it can be easily molded and remolded into different products. Another benefit is that, unlike many other forms of bio-plastics, it won’t ruin the recycling process. 


Luna Yu said: “Many people throw bio-plastics into the recycling bin rather than the compost, but if it’s not a thermoplastic, it can’t be remolded,” says Yu.

“This disrupts the physical properties of new recycled products — they will end up falling apart.”

PHAs won’t cause this problem if it accidentally ends up in recycling bins, which makes it much easier for waste management companies to handle.

But what really sold Yu on PHAs is the fact that it’s fully biodegradable. PHAs degrade within one year in a terrestrial environment, and fewer than 10 years in marine environments. Meanwhile, synthetic plastics can take hundreds of years to degrade in similar environments.

Given its superior physical properties and the process it takes to create, Yu says Genecis’s PHAs are best suited for higher-end products like toys, flexible packaging, 3D-printing filament and medical applications including surgical staples, sutures and stints.

Luna Yu said:
“The PHAs we create can be used to make pretty much anything, but it makes the most economic sense to use it in higher-quality, multi-use products.”
While PHAs have been in the market for the past two decades, most come directly from corn and sugarcane crops. Yu explains that the process Genecis uses to create its PHAs is much cheaper because they avoid the expenses required to acquire their feedstock.


Three-step Process


Genecis uses a three-step process to produce its PHAs, explains Michael Williamson, the company’s head of mechanical engineering and U of T engineering grad.
  • First, they use a mixture of anaerobic (without oxygen) bacteria that breaks down the food waste into volatile fatty acids, similar to how food is broken down in our stomachs. 
  • Next, the fatty acids are added to a mixed culture of aerobic (with oxygen) bacteria that are specially selected to produce PHAs in their cells. 
  • Finally, they use an extraction process to break open the cells, collect and purify the plastic.

The process takes less than seven days from getting the food waste to having the purified plastic — making biogas, on the other hand, takes an average of 21 days. When the company opens its demonstration plant later next year, it will be able to convert three tons of organic waste into PHAs weekly. 


While the process used by Genecis works for pretty much all types of food, some foods like simple carbs and proteins can be more efficiently converted, says Yu.
The company currently has two locations — their main lab in U of T’s Banting and Best Building, in the heart of Toronto’s Discovery District, and the other in the Environmental Science and Chemistry Building at U of T Scarborough, which is responsible for research and development.


U of T start-up


In their downtown lab they work with pilot-scale bioreactors, and are continuing to scale up their operations with an industry partner to a demonstration plant by the end of next year. Meanwhile, their facility at UTSC houses smaller bioreactors that are used to help optimize their production process.

Vani Sankar, Genecis’s head of biotechnology and a postdoc at U of T Scarborough, said:
“We’re fine-tuning things to figure out the best conditions to operate our bacteria cultures. This includes what combinations of temperature, pH and amount of food will give us the best yield.”
 
Source: University of Toronto Scarborough



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