Who Ya Gonna Call?
(psst — it’s not ghostbusters)
I know many things are causing a mess to the beautiful blues and greens that make planet Earth look so unique to other planets.
But I want to focus on one factor right now: plastic waste.
It’s one of those things that many people say we could reduce if everyone just collaborated. But it would never be easy, because how could we do that when we so heavily rely on plastic? From medical equipment to things in our homes, we use plastic in basically everything.
Besides, as optimistic as I’d like myself to be, when has all the human race collaborated about anything? We couldn’t even collaborate during the pandemic. Some people thought it was a lie, others thought it was an apocalypse. Everyone has their own opinion about everything. What seems obvious to you may seem ridiculous to somebody else. And that’s no different about plastic use and waste.
As I’m typing this, I can think of tons of things in my house made up of plastic: drink bottles, plastic food bags and wraps, toothbrushes, cleaning equipment, CLOTHES! I could go on.
That’s not an excuse though. We can’t just say “I use plastic too much, so no, I can’t stop using it”. We can reduce plastic use in our lives. But realistically, I don’t think we can 100% eliminate it. And since we may never (or not in the near future) be able to stop plastic waste, we should probably find something “magical” that will get rid of it.
Plastic Busters!
“Plastivores” are organisms that use plastic as their main energy source, breaking it down to its smaller parts that are either unharmful to the environment or can be reused to make new plastics.
What makes plastivores amazing is that they aren’t just another artificial chemical, but rather a life form that can help reduce plastic pollution. Almost like using nature to tidy up our mess.
Scientists have found more than 50 species of “plastivores” that can ‘eat’ plastic, such as bacteria, fungi, microbes and even a type of larvae.
Some specific examples of these strange “plastivores” that I found particularly interesting were:
1. A. terreus & E. album
I was excited when I found out that these “plastivores” were found recently (as in 2023 recently).
Scientists at the University of Sydney have found that A. terreus and E. album (types of fungi that are found in plants and soil) are capable of breaking down polypropylene (a thermoplastic polymer).
When I first read about this, the first thing I questioned was how on earth a mushroom can break down plastic. According to ChatGPT, fungi don’t have secret tiny mouths…
Instead, they secrete powerful enzymes that break down plastic so that it can be small enough to be absorbed by the mycelia, which are like the roots of fungi.
It was found that A. terreus and E. album were able to break down 27% of plastic in 90 days. Even better still, if the plastic was exposed to UV rays or heat beforehand, the fungi were able to break down the plastic completely in only 140 days. If that doesn’t stun you, I don’t know what will.
2. Wax worms
I liked the story of how this one was found.
Wax worms are the caterpillars of the Greater Wax Moth. They are also referred to as pests because they tend to infiltrate bee nests and eat the beeswax and honey.
They came to be known as plastivores accidentally, when a scientist-beekeeper found them munching away in one of her hives whilst she was cleaning it.
She put them in a plastic bag and the next time she came to pick the bag up, she found that they had eaten through the plastic. And that’s how it was discovered that the wax worm can eat plastic. It’s a cool story, right?
After their plastic meal, they excrete a type of alcohol called ethylene glycol (a polyester and antifreeze). Studies have found that they can solely live off polyethylene during their two-to-four-week life span, eating about 1.84mg of plastic each day without a problem.
Some scientists believe it's possible to have whole facilities where these grubs can be used to dispose of plastic. But there would have to be a lot (and I mean A LOT) of wax worms just wriggling around in those types of plastic waste facilities (shivers).
3. Ideonella sakaiensis
Similar to the wax worm, I. sakaiensis was also discovered by accident outside a bottle factory in Japan in 2016. Usually, bacteria eat dead organic matter. But I. sakaiensis wanted the plastic polyethylene terephthalate (PET) for lunch.
At that time, it was the first known bacteria to be able to break down plastic and use it as its main source of energy. So, this was a very exciting discovery as you can imagine.
Since this finding, it has been discovered that I. sakaiensis uses two types of digestive enzymes to break down plastic called PETase. This information is now being used in genetic engineering (more on this below).
So, Who Ya Gonna Call? Plastic Busters!
Plastivores (as they are right now) are probably not the solution (or at least the final solution) to the plastic waste problem the world is facing today. However, they can be the foundation for a bigger method of plastic disposal.
By using plastivores as role models, scientists have been inspired to innovate, considering things they may not have thought of without them.
For example, the enzymes of certain plastivores could be isolated to act as the “magical potion” for plastic disposal, such as PETase.
Another example is using genetic engineering to improve plastivores. Many genetic scientists have experimented with I. sakaiensis to increase its productivity. Some are even trying to genetically engineer bacteria that are more efficient at enzyme production, such as E. coli, to turn them into PETase factories.
Researchers have also been studying the synergistic effects that cause the accelerated breakdown of plastic between an organism and its isolated bacteria/enzyme. For example, microbes responsible for the plastic breakdown in the gut of the wax worm don’t work as effectively when isolated as they do in the actual wax worm itself.
So, as you can see, there are still many unanswered questions, studies and improvements yet to be done on plastivores. Even then, this method of plastic waste removal is promising.
Though not all scientists believe it is sufficient enough as a “forever” solution, plastivores may be the key that could open doors never seen before to help contribute to the reduction in plastic waste management.
If that ever happens, maybe one day we’ll have a special number to call the “Plastic Busters” and get rid of the ghosts of our past (that being plastic waste) …
Thanks for reading :)
Sources:
- From fiction to reality: the potential of plastic-eating organisms | Fix (grist.org)
- Scientists find fungi that can eat plastic (cosmosmagazine.com)
- Why scientists say ‘plastivores’ could be the solution to plastic pollution — WHYY
- Plastic-eating bacteria: Engineering and impact | Live Science
- Fungi makes meal of hard-to-recycle plastic — The University of Sydney
