A couple That Will Eliminate Plastic
Plastics have become abundant in our lives and landfills. Since they do not biodegrade, they accumulate and spread, creating environmental and health issues. Scientists have been searching for ways to break down plastics. An answer lies in the organisms around us. The bacteria, Ideonella sakaiensis, is one organism that contains an enzyme called PETase. PETase breaks down polyethylene terephthalate (PET), a polymer of plastic, into terephthalic acid and ethylene glycol. These monomers can be utilized to synthesize new plastics. Yet, a new theory to upcycle plastics is to create a relationship between Ideonella sakaiensis and a fungus. The bacteria will be able to seek protection in the mushroom. In return, the monomers resulting from PET degradation by the bacteria will be utilized by the fungus to grow biomass. This would facilitate the growth of mycelium or the root system of the fungus. We would harvest the mycelium for commercial uses such as packaging and architecture. This would allow us to replace plastic packaging.
Polyethylene terephthalate (PET) is found in plastics
It is undeniable that plastics are currently a significant global issue that reaches far into our environmental, economic, and health realms. Plastics started to replace traditional paper and glass containers in the 1960s and 1970s and became mass consumed by the public. Over the last 70 years, plastic production has increased from 1.5 million tonnes to close to 400 million tonnes in 2022. However, despite its convenience and its initial purpose of preventing exploitation of natural resources such as ivory, glass, wood and paper, it is now believed to have deleterious effects on our health and environment. The major problem with plastic is that we produce too much of it and it does not biodegrade. It can take up to 1000 years to break down large plastics into smaller pieces, but plastics truly never disappear. In a world where we produce so much non-biodegradable material, we must find a way to reduce the production of plastics and recycle plastic that has already been produced.
So How do Organisms Break Down Plastics?
Polyethylene terephthalate (PET) is a compound found in plastics
Few organism can break down plastics; they contain PETase
PETase: An enzyme that hydrolyzes polyethylene terephthalate (PET) into its monomers, terephthalic acid and ethylene glycol
Isolated from Ideonella sakaiensis–a bacteria–by scientist in Japan (2016)
PETase is being researched to make it more effective on a larger scale
Ideonella sakaiensis
A bacteria discovered by scientists in Japan in 2016 that has PETase, an enzyme that hydrolyzes polyethylene terephthalate into its monomers, terephthalic acid and ethylene glycol.
What do we have so far…
Ideonella sakaiensis breaks down PET into terephthalic acid and ethylene glycol
Plastic can be both recycled or upcycled:
Recycling - Monomers are synthesised into plastic again
Recycling the monomers back into plastics reduces the quality and value of the plastic
Upcycling - Monomers can be used to produce new materials
Vanillin: a compound of vanilla that is produced when E.coli consumes PET monomers
A possibility?
To help eliminate plastic waste, we can create a symbiotic relationship between Ideonella sakaiensis and fungi. I. sakaiensis produces an enzyme called PETase that breaks down PET plastics into monomers like terephthalic acid and ethylene glycol. These byproducts can then be consumed by fungi, which use them to generate biomass. As the fungi grow, they form mycelium—networks of thread-like fibers—that can be molded and dried into biodegradable materials. This sustainable process has the potential to replace traditional plastics in packaging and architectural applications.
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