Believe it or not, there are plastic-eating bacteria in our oceans and landfill sites munching away at our plastic pollution problem.
However, every silver lining has a cloud, and these tiny organisms could be that cloud!
The Plastic Problem
Thankfully, our attitude to plastic is changing, but sadly, that is not reflected in our ever-increasing plastics production rate.
Did you know that:
We still produce over 300 million tonnes of plastic each year, and our plastic waste can be found everywhere.
We have even made space our dumping ground. Just think of all the now-defunct satellites floating around!
Recently, Victor Vescovo, a retired naval officer, descended nearly 35,853ft (10,927 meters) into the Mariana Trench in the Pacific Ocean.
This is known as the deepest place on earth, yet he discovered what he believes to be plastic pollution even here.
This is worrying as it proves that plastic waste can now be found lurking in every area of the earth.
From space to a mountain top, from forest to ocean, nowhere is clear of this almost indestructible menace.
The Emergence Of Plastic-Eating Bacteria.
Bacteria, or microbes, if you prefer, are the most abundant life on earth and have an extraordinary ability to adapt to their surroundings.
It has been said that “If you put bacteria in a situation where they have only one food source, over time they will adapt to consume it.”
This is also true if food sources are abundant as mother nature does not like to see anything go to waste.
Where did it all begin?
In 1907 Leo Hendrik Baekeland made the first synthetic plastic.
By 2020 that plastic had grown to thousands of different types. Plastics simply aren’t one material made the same way every time.
This is why some plastics are single-use, and others are recyclable.
Although the grim fact is that only about 10% of recyclable plastics ever get recycled, but that’s another story.
For this story, just know that, In weight alone, plastics equate to about 300 million tonnes produced annually.
Here comes the fun bit!
Bacteria will eat anything, and if you are a bacteria, that’s a lot of food if you can exploit it!
The only thing bacteria needed was the time to adapt and evolve to this new medium.
Well, no problem there!
Humankind has been dumping plastics since its creation in 1907, and now with so much plastic sitting in degradation, bacteria has finally achieved its goal.
In 2016 Japanese scientists researching landfill sites made the first discovery of a new strain of bacteria.
What they discovered was a new strain of bacteria that was eating its way through the plastic.
Polyethylene Terephthalate, to be precise or, PET for short. (The thin malleable sort of plastic that disposable water bottles are made from).
The Plastic Munching Breakthrough
After this discovery, another group of scientists looked at the bacteria on a molecular level and isolated the enzymes that it was using.
With this knowledge, they then created a new enzyme (by accident, not design), building on the original strength and boosting its power by about 20%.
These enzymes were then applied to a thin plastic (PET) bottle.
Amazingly the bacteria broke the bottle’s structural integrity in just a couple of days.
Don’t worry, though; your home appliances aren’t about to spontaneously disintegrate!
The aim of the team was to create an enzyme that can safely break down plastics at a molecular level in a controlled environment.
Once these “super” enzymes have completely broken down the plastic, there should only be a clear solution remaining.
The hope is that this clear biodegraded plastics solution can then be filtered and recycled into entirely new plastic.
It is quite a big task, but it will enable us to close the loop on disposable plastics if this momentous breakthrough is made.
Wow, think of the environmental impact number and the number of resources that could be saved!!!
This is great news for our futures and the future of bio-based plastics recycling.
However, they are not alone!
Further investigations and studies have shown other natural strains of bacteria evolving and developing plastic-eating capabilities.
Wikipedia reports the following:
Some of the organisms that break down plastics include:
- Aspergillus tubingensis: breaks down polyurethane
- Bacillus pseudofirmus: breaks down LDPE
- Exiguobacterium sibiricum: breaks down polystyrene
- Galleria mellonella caterpillars: breaks down polyethylene
- Geotrichum candidum: breaks down polycarbonate
- Ideonella sakaiensis: breaks down PET
- Tenebrio Molitor larvae: breaks down polystyrene
- Arthrobacter sp. KI72: breaks down 6-aminohexanoate
- Pestalotiopsis microspora: breaks down polyurethane
- Salipaludibacillus agaradhaerens: breaks down LDPE
- Exiguobacterium undrae: breaks down polystyrene
There is also some evidence that may point to a wealth of undiscovered bacterial strains eating the plastics in the world’s oceans.
The Case For Plastic-Eating Marine Bacteria.
It has been estimated that there are typically about 40 million bacterial cells in a gram of soil.
That’s a lot of bacteria.
However, scientists from the University of Georgia estimate the number of bacteria on our planet to be five million trillions!
Or in other words, there are more bacteria on earth than there are stars in the universe.
Therefore, it would not be a huge leap to consider that marine bacteria, just like their land-bound counterparts, would evolve to eat plastics.
It has been estimated that 8 million metric tons of plastic enter our oceans every year. Of this plastic detritus, over 50% sinks to the bottom of the ocean, hiding it from sight.
The remainder Floats on the surface where due to the combined action of UV light and weathering, it slowly begins to break apart.
When subjected to UV light and other factors, most plastics become brittle and break down into smaller pieces.
Here Comes The Mystery
Given our knowledge of plastics’ birth, usage, and the amount dumped into the oceans, we can estimate how much should be there.
However, even with very low conservative estimates, the actual amount seems to be about 1/10th of the amount predicted.
So, where has it all gone?
One explanation might be that living organisms such as plastic-eating bacteria are slowly munching away at our plastic pollution problem.
A 2019 study into the biodegradation of plastic films by marine consortia observed that these organisms did indeed exist.
Furthermore, laboratory testing showed a reduction in certain plastics’ mass over a 5 month time period.
It is also hypothesized that there are many more, as yet, undiscovered plastic-eating bacteria in the world’s oceans.
This would certainly go some way into explaining the apparent loss of plastic pollution present in our oceans.
Another explanation might be that the plastic has broken up into pieces so small that we simply cannot see it.
These Micro and nano plastics are in all food chain areas and are slowly killing our wildlife.
However, the mere presence of the plastic-eating bacteria leads us to believe that all is not lost.
Are Plastic-Eating Bacteria A Good Thing?
It is believed that the steady degradation and weathering of plastics enable the plastic-eating bacteria to take hold.
This information is taken from combining scientific observations and controlled laboratory experiments.
However, this may be the cloud behind the silver lining and not the ideal solution for the environment and ecology.
The Bad News
As the bacteria break down (consumes) plastic, it releases the additives or toxins trapped within it. These toxins are then free to be absorbed by the environment surrounding them.
That environment may be the sea, the air, or even the stomach of an animal that has eaten it.
Why would an animal eat plastic, I hear you say?
Well, research has proven that many animals are unwittingly eating plastic and storing it within their stomachs. (More about that later).
The burning question to be asked is:
What Are The Real World Effects Of Plastic Eating Bacteria?
Aside from the potential release of toxins, the many plastic shards created are a real danger to life.
Plus, as the plastic degrades, the pieces become ever smaller. This means that if we cannot find a way to accelerate the biodegradation process, every size of an animal is in danger.
The danger is that the pieces of plastic will become conveniently mouth-sized to all living creatures.
From whales to plankton, nothing will be safe.
Unsettlingly, large plastic pieces have already been found in the stomachs of many thousands of animal species.
For evidence of this, you only need to watch the film “A Plastic Ocean,” but beware as there are many upsetting scenes.
One answer to this, “how to make it safe problem,” may be to make the enzyme indigestible to other living creatures.
The Good News
However, it’s not all bad news, as we are still only dealing with hypotheticals here.
The good news is that a naturally occurring marine enzyme has been found that degrades plastic.
This enzyme does not appear to damage its host when digested, and it may be cleaning up the world’s waterways and oceans.
Plus, research into this plastic-eating bacteria may hold answers for clearing up oil spills and other human-made disasters.
Plastic-eating bacteria may also enable us to convert single-use plastics into fuel or multi-use materials. They could also be engineered to accelerate and improve their biodegrading abilities.
In this way, we might be able to speed up further the process of cleaning the land, waterways, and oceans of the world.
Who knows, maybe we can return to clean oceans, healthy wildlife, and a myriad of living species on the rise.
How Fast Do Plastic-Eating Bacteria Eat Plastic?
This is a hard question to answer given the small amount of study completed on this new and interesting discovery.
However, it must also be remembered that laboratory conditions are no substitute for the real world.
In the real world, contributing factors would include:
- Strength and duration of UV light
- Number of plastic-eating bacteria in the colony
- Amount of oxygen present
- Type and grade of plastic plus additives
- Environments it may be exposed to
- Other bacteria strains present
- Type and strain of dominant bacteria
All that being said, let’s remember that we have literally mountains of plastic pollution already, and we don’t’ want this discovery to halt any of our plastic reduction efforts.
These are incredibly early days for research into these bacterial strains.
However, with an estimated 9.1 billion tonnes of plastic on the planet, it’s good to know that a solution might be in sight.
This is good news, and really it looks as though it’s the cloud with a silver lining for the human race.
Plastic-eating bacteria are now with us. They seem to be fitting into the natural environment and are beginning to work on our plastic pollution problem.
However, the real learning is that we cannot continue to create products that threaten all life on earth.
To really tackle the problem, we don’t need to produce a new solution that may have unforeseen effects.
We need to find a way to stop pollution in the first place.