Following is the full transcript of senior researcher assistant Morgan Vague’s talk titled “The Bacterial Solution to Plastic Pollution” at TEDxMtHood conference.
Morgan Vague – TEDx Talk TRANSCRIPT
Plastics. You know about them, you may not love them, but chances are you use them every single day. Enough plastic is thrown away each year to circle the globe four times.
By 2050, researchers estimate that there will be more plastic in the ocean than fish. In fact, there are two islands of floating plastic waste twice the size of Texas in our oceans right now.
Despite our best efforts, only 9% of all plastic we use winds up being recycled. And even worse, plastic is incredibly tough and durable and researchers estimate that it can take anywhere from 500 to 5,000 years to fully break down.
Now this plastic doesn’t just sit in our oceans and landfills like a harmless eyesore. No. Instead it leaches harmful chemical contaminants into our oceans, our soil, our food, our water, and into us.
SO HOW DID WE WIND UP WITH SO MUCH PLASTIC WASTE?
Well, it’s simple. Plastic is cheap, durable, adaptable, and it’s everywhere. If you look around you, you will find plastic in most things from this microphone to this projection screen. Plastic is everywhere.
But the good news is there’s something else that’s cheap, durable, adaptable and everywhere. And my research shows it may even be able to help us with our plastic pollution problem.
I’m talking about bacteria. Bacteria are microscopic living beings invisible to the naked eye that live everywhere, in all sorts of diverse and extreme environments, from the human gut, to soil, to skin, to vents in the ocean floor, reaching temperatures of 700 degrees Fahrenheit.
Bacteria live everywhere, in all sorts of diverse and extreme environments. And as such, they have to get pretty creative with their food sources. There’s also a lot of them. Researchers estimate that there are roughly five million trillion trillion — that’s a five with 30 zeros after it — bacteria on the planet.
Now, considering that we humans produce 300 million tons of new plastic each year and go through about 10 billion plastic bags per day, I’d say that our plastic numbers are looking pretty comparable to bacteria’s.
So, after noticing this and after learning about all of the creative ways that bacteria find food, I started to think: could bacteria in plastic-polluted environments have figured out how to use plastic for food?
Well, this is the question that I decided to pursue a couple of years ago. Now, fortunately for me, I’m from one of the most polluted cities in America: Houston, Texas.
In my hometown alone, there are seven EPA-designated Superfund sites. These are sites that are so polluted, that the government has deemed their cleanup a national priority.
So I decided to trek around to these sites and collect soil samples teeming with bacteria. I also collected some samples from the beautiful brown waters of Galveston Bay, Texas, the plastic polluted beach of my childhood.
And after employing some creative methods, let’s say, of getting these bacteria on a plane and back to Portland, I got to work. I started toying with a protocol, which is fancy science talk for a recipe.
And what I was trying to cook up was a carbon-free media, or a food-free environment. An environment without the usual carbons, or food, that bacteria, like us humans, need to live.
Now, in this environment, I would provide my bacteria with a sole carbon, or food source. I would feed my bacteria polyethylene terephthalate, or PET plastic.
PET plastic is the most widely produced plastic in the world. It’s used in all sorts of food and drink containers, with the most notorious example being plastic water bottles, of which we humans currently go through at a rate of 1 million per minute.
So, what I would be doing, is essentially putting my bacteria on a forced diet of PET plastic and seeing which, if any, might survive or, hopefully, thrive.
See, this type of experiment would act as a screen for bacteria that had adapted to their plastic-polluted environment and evolved the incredibly cool ability to eat PET plastic. And using this screen, I was able to find some bacteria that had done just that. These bacteria had figured out how to eat PET plastic.
SO HOW DO THESE BACTERIA DO THIS?
Well, it’s actually pretty simple. Just as we humans digest carbon or food into chunks of sugar that we then use for energy, so too do my bacteria. My bacteria, however, have figured out how to do this digestion process to big, tough, durable PET plastic.
Now, to do this, my bacteria use a special version of what’s called an enzyme. Now, enzymes are simply compounds that exist in all living things. There are many different types of enzymes, but basically, they make processes go forward, such as the digestion of food into energy.
For instance, we humans have an enzyme called an amylase that helps us digest complex starches, such as bread, into small chunks of sugar that we can then use for energy.
Now, my bacteria have a special enzyme called a lipase that binds to big, tough, durable PET plastic and helps break it into small chunks of sugar that my bacteria can then use for energy. So basically, PET plastic goes from being a big, tough, long-lasting pollutant to a tasty meal for my bacteria. Sounds pretty cool, right?