Project Nema: Genetically Engineering the Next Generation of Plastic-Eating Decomposers
We humans are really bad at cleaning up after ourselves.
With over 5 trillion metric tons of plastic polluting our world, only 8–9% of it gets recycled. 3.1 million tons of PET (polyethylene terephthalate), a commonly used plastic polymer, is produced every single year, leaving a total of 3 trillion tons of plastic in Canada and the US alone.
With this being such a big problem, we haven’t found a way to entirely get rid of this plastic sustainably. Sure, many people do burn tons of plastic to get rid of it but at the end of the day, it’s only going to release more toxins and chemicals in the air that add to climate change, and cause serious health issues. Another way is to break down plastic into microplastic, but the plastic is still there. Not to mention that microplastic can cause more health issues to humans and the environment.
Finding a method to decompose plastic sustainably will not only help recycling plants but can also help remove plastic from our world to prevent the effects of global warming, create fewer health issues within the environment, and more.
We haven’t found anything or any way to fully break down plastic…. until now…
The Ideonella Sakaiensis Bacteria
In 2016, researchers in Japan discovered the bacteria ideonella sakaiensis and its unbelievable properties, allowing it to break down PET.
How does the bacteria do this?
Well, the bacteria produce two enzymes (PETase and MHETase), each focusing on a specific task.
The first enzyme, PETase, cuts the polyester polymer of which PET is constructed into smaller pieces. During this process, PET is converted into mono-(2-hydroxyethyl) terephthalate acid (MHET), terephthalate (TPA), and bis(2-hydroxyethyl) TPA (BHET).
Then the second enzyme produced by ideonella sakaiensis, MHETase, comes into play. This enzyme converts the MHET into ethylene glycol and TPA. — (University of Denmark Education)
Note: PET & PETase and MHET & MHETase are all different substances/enzymes.
This seems like a lot to digest, but essentially, the PETase enzyme is what cuts the main part of PET and converts that into these different types of substances.
After the first enzyme broke down the PET substance into substances like MHET, the bacteria’s second enzyme starts to work. This enzyme, MHETase, converts MHET into two substances that can easily be broken down by microorganisms — resulting in CO2(carbon dioxide) and H2O(water).
Why aren’t we using these bacteria?
So, if this bacteria can break down plastic, why aren’t we already using it to fix this problem?
The main reason is that these bacteria mainly live in swamps, and most of the research conducted was confined within a controlled lab environment. Recycling depots aren’t swamps or “controlled lab environments,” which means that the bacteria won’t be able to survive in those conditions… on their own.
This is our company comes into play.
At Nema, instead of solely relying on the ideonella sakaiensis bacteria to work in these conditions, we decided that, instead, we would put this bacteria inside a natural decomposer (nematodes), so that we could create plastic-eating decomposers.
This will be done through something called Gene Editing. More specifically, CRISPR Cas9.
A bit about Gene Editing
Gene Editing is a form of technology that allows us to manipulate any living organism’s gene.
This is done through a process known as CRISPR.
CRISPR is a defensive mechanism that was used by bacteria to defend themselves from viruses (phages) that can input their DNA into the bacteria. The CRISPR DNA would create a type of RNA known as the cRNA to destroy these viruses in the gene.
Scientists have found a way to hijack this CRISPR system to manipulate any living organism’s gene.
With this CRISPR technology, we will also be using the Cas9 enzyme, which is primarily used to cut the target DNA.
One of the biggest reasons why we are using nematodes is the fact that they have already been genetically engineered before. Research conducted by the Japan Science and Technology Agency discusses genetically modifying nematodes like the C. elegans(the one we’re using) nematodes. Genetically editing nematodes that have already been tested on will allow us to have safer tests and can provide us with a more accurate starting point compared to other decomposers like earthworms.
Genetically Engineering the Nematodes
We will be using this CRISPR system to isolate the non-coding intron of a gene in the Caenorhabditis elegans nematode and replace it with the ideonella sakaiensis bacteria instead. Since this is a germline gene, the bacteria will be passed down to future nematode generations, which will ultimately allow the nematodes to gain the ability to break down plastic, without performing any edits! Allowing for exponential growth!
Now, nematodes are generally extremely small, and so just one alone won’t be able to do that much. This is why we are going, to begin with, 1000 nematodes. However, genetically engineering each individual nematode is going to take a lot of time and money, and wouldn't be too practical.
So, what are we going to do?
Editing Nematodes through Food
What if instead, we could get these nematodes to eat the bacteria…
This might sound a bit crazy, but it could be the solution.
If we genetically modify the food that these nematodes eat, it could alter their genetic code. This is essentially what GMOs or genetically modified organisms are.
Now, how are you going to get the bacteria from one organism to the other?
Liposomes are (spherical) vesicles used as a drug delivery vehicle for the administration of nutrients and pharmaceutical drugs, such as lipid nanoparticles in mRNA vaccines, and DNA vaccines.
Now, if we can use this system in genetically modified food, we can essentially get these liposomes to carry the ideonella sakaiensis bacteria and the CRISPR system into the nematode’s gene.
Once this has been completed, the liposome will then open, releasing the CRISPR Cas9 system to find the non-coded intron in the gene of the nematode, and replace it with the ideonella sakaiensis bacteria.
And boom! We now have plastic-eating decomposers.
Our Vision for the Future
With this global plastic problem, we can see the world turning into a dystopian one all because we didn’t take care of our environment properly. There would be more people dying, more people getting sick, less food to go around, etc.
Our idea will not only prevent this future from happening, but it will also make the future a great one.
We will begin by targetting plastic in landfills, as these places are isolated, yet still contributes to a ton of plastic pollution.
By effectively decomposing plastic in landfills, we can reduce the total amount of plastic pollution by 86 percent in Canada alone within 10 years. The time it takes to decompose this plastic is only going to decrease, and the number of nematodes will continue to increase.
Our vision can see a future where we don’t have to walk around stepping on plastic everywhere, a future where we don’t need to work in huge landfills to get rid of plastic, a future where we don’t have to worry about plastic.
Thank you for reading this article. We hope you have gained enough knowledge to understand how we, Nema, will eradicate this plastic pollution problem. You can visit us today at nema.world.