Plastic pollution, the problem we cannot ignore this Earth Day
This new genome-based platform provides a scalable, stable and sustainable alternative for next-generation biocatalysis in plastic waste remediation.
SEATTLE (Scrap Monster): Plastic pollution has become a global environmental crisis over the past 70 years, with millions of tons manufactured and less than 10% being effectively recycled.
Plastic waste has been continually mismanaged worldwide, affecting both human health and the natural environment. The long-term impacts of micro- and nano-plastics on the human body are still being uncovered, but their detection in the human brain and even in unborn babies is deeply concerning.
For Dr. David Levin, Professor, Department of Biosystems Engineering, finding a solution to this problem felt urgent.
'We have woefully inadequate systems to deal with plastic waste,” says Levin. “We urgently need to address the problem with a stable and sustainable bioengineered solution.”
Plastic is everywhere
Most consumer goods contain synthetic plastic materials, from plastic bags and packaging to electronics and car parts. It is durable, moldable, sterile, chemically stable and cheap to produce, making it appealing for manufacturers.
On the flip side, most plastics cannot be recycled in any meaningful way and very little is ever made into useful end-products. Plastics also degrade in quality every time they are recycled. This means that they cannot be reused indefinitely, like glass or metal, and eventually become waste. In reality, recycling is more of a delay mechanism than the solution to getting rid of plastic waste.
“Recycling is complex on many levels,” says Levin. “There are overlapping economic, physical and regulatory problems that span fluctuating resale market pricing, harmful residue and polymer contamination.”
While plastic recycling has long been promoted as the central strategy for reducing pollution, the reality is that recycling programs are not living up to their promises. The system cannot keep pace with the scale or complexity of global plastic waste.
Don’t we already have biodegradable plastic products?
Items like the flimsy produce bags you might find at a grocery store can be biodegradable, but only if the conditions are absolutely perfect. They require a temperature of 60 degrees Celsius to degrade. The chemicals applied to break down the plastic bag also require sufficient light and oxygen, along with chemical supplements to allow the bacteria to live and feed on the plastic. Those variables cannot be controlled in a landfill.
Levin sees a solution
Levin and the multidisciplinary team at the University of Manitoba are working on a bioengineered solution that offers a fundamentally different path to dealing with plastic waste.
In a recent article published in The Journal of Hazardous Materials, Levin and three UM researchers - Katherine Romero-Orejon (Biosystems Engineering), Hamid Reza Karbalaei-Heidari (Chemistry) and Nediljko Budisa (Chemistry) - report a major advancement in microbial degradation processes of certain plastics.
Breaking down plastics
Their goal is to transform polyethylene terephthalate (PET), the plastic commonly used for drink containers, by breaking it down on a molecular level with special bacteria and enzymes capable of digesting it. They are seeking to convert plastic into harmless byproducts or even enable the bacteria to produce high-value products like biodegradable plastics or fungicides, in a safer and less energy intensive way. The team is creating stable strains of biocatalysts that constitutively produce and surface-anchor active enzymes.
Plastic eating bacteria
Levin and the team have successfully created the next generation of genetically stable biocatalysts. Their strain of plastic eating bacteria does not require anti-biotics and chemical inducements to survive and break down the plastic. This development is showing promise compared to previous biodegradable platforms that required special attention to keep the bacteria alive and productive.
This new genome-based platform provides a scalable, stable and sustainable alternative for next-generation biocatalysis in plastic waste remediation.
“So far, these catalysts are showing promise in degrading PET particles and films under laboratory conditions.” This strategy can also be applied to other types of plastic materials.
Levin’s new technology is a potential plastic recycling game changer. This approach of using biocatalysts to breakdown plastics can be applied to many other types of plastic wastes, and represents the next step in developing an engineered solution to reducing plastic waste.
Where recycling tries to address symptoms of the plastic waste problem, bioengineering solutions aim to redesign the system.
Courtesy: www.umtoday.ca