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Plastics: you know about them,[br]you may not love them,

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but chances are[br]you use them every single day.

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By 2050, researchers estimate

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that there will be more plastic[br]in the ocean than fish.

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Despite our best efforts,

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only nine percent of all plastic we use[br]winds up being recycled.

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And even worse,

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plastic is incredibly tough and durable

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and researchers estimate

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that it can take anywhere[br]from 500 to 5,000 years

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to fully break down.

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It leaches harmful chemical contaminants[br]into our oceans, our soil,

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our food, our water, and into us.

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So how did we wind up[br]with so much plastic waste?

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Well, it's simple.

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Plastic is cheap, durable,[br]adaptable, and it's everywhere.

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But the good news is

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there's something else that's cheap,[br]durable, adaptable and everywhere.

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And my research shows[br]it may even be able to help us

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with our plastic pollution problem.

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I'm talking about bacteria.

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Bacteria are microscopic living beings[br]invisible to the naked eye

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that live everywhere,

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in all sorts of diverse[br]and extreme environments,

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from the human gut, to soil, to skin,

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to vents in the ocean floor, reaching[br]temperatures of 700 degrees Fahrenheit.

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Bacteria live everywhere,

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in all sorts of diverse[br]and extreme environments.

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And as such, they have to get[br]pretty creative with their food sources.

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There's also a lot of them.

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Researches estimate that there are[br]roughly five million trillion trillion --

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that's a five with 30 zeros after it --[br]bacteria on the planet.

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Now, considering that we humans produce

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300 million tons of new plastic each year,

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I'd say that our plastic numbers

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are looking pretty[br]comparable to bacteria's.

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So, after noticing this

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and after learning[br]about all of the creative ways

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that bacteria find food,

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I started to think:

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could bacteria in[br]plastic-polluted environments

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have figured out[br]how to use plastic for food?

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Well, this is the question that I decided[br]to pursue a couple of years ago.

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Now, fortunately for me,

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I'm from one of the most[br]polluted cities in America,

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Houston, Texas.

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(Laughs)

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In my hometown alone,

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there are seven EPA-designated[br]Superfund sites.

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These are sites that are so polluted,

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that the government has deemed[br]their cleanup a national priority.

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So I decided to trek around to these sites

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and collect soil samples[br]teeming with bacteria.

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I started toying with a protocol,

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which is fancy science talk for a recipe.

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And what I was trying to cook up[br]was a carbon-free media,

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or a food-free environment.

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An environment without the usual[br]carbons or food

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that bacteria, like us,[br]humans, need to live.

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Now, in this environment,

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I would provide my bacteria[br]with a sole carbon or food source.

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I would feed my bacteria[br]polyethylene terephthalate

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or PET plastic.

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PET plastic is the most widely produced[br]plastic in the world.

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It's used in all sorts[br]of food and drink containers,

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with the most notorious example[br]being plastic water bottles

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of which we humans currently go through[br]at a rate of one million per minute.

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So, what I would be doing,

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is essentially putting my bacteria[br]on a forced diet of PET plastic

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and seeing which, if any,[br]might survive or, hopefully, thrive.

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See, this type of experiment[br]would act as a screen

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for bacteria that had adapted[br]to their plastic-polluted environment

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and evolved the incredibly cool[br]ability to eat PET plastic.

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And using this screen,

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I was able to find some bacteria[br]that had done just that.

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These bacteria had figured out[br]how to eat PET plastic.

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So how do these bacteria do this?

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Well, it's actually pretty simple.

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Just as we humans digest carbon or food[br]into chunks of sugar

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that we then use for energy,

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so too do my bacteria.

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My bacteria, however, have figured out[br]how to do this digestion process

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to big, tough, durable PET plastic.

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Now, to do this,[br]my bacteria use a special version

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of what's called an enzyme.

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Now, enzymes are simply compounds[br]that exist in all living things.

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There are many different types of enzymes,

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but basically, they make[br]processes go forward,

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such as the digestion of food into energy.

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For instance, we humans[br]have an enzyme called an amylase

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that helps us digest[br]complex starches, such as bread,

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into small chunks of sugar[br]that we can then use for energy.

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Now, my bacteria have[br]a special enzyme called a lipase

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that binds to big, tough,[br]durable PET plastic

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and helps break it[br]into small chunks of sugar

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that my bacteria can then use for energy.

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So basically,

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PET plastic goes from being[br]a big, tough, long-lasting pollutant

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to a tasty meal for my bacteria.

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Sounds pretty cool, right?

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And I think, given the current scope[br]of our plastic pollution problem,

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I think it sounds pretty useful.

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The statistics I shared with you

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on just how much plastic waste[br]has accumulated on our planet

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are daunting.

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They're scary.

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And I think they highlight

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that while reducing, reusing[br]and recycling are important,

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they alone are not going to be enough[br]to solve this problem.

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And this is where I think bacteria[br]might be able to help us out.

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But I do understand[br]why the concept of bacterial help

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might make some people a little nervous.

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After all, if plastic is everywhere[br]and these bacteria eat plastic,

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isn't there a risk of these bacteria[br]getting out in the environment

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and wreaking havoc?

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Well, the short answer is no,[br]and I'll tell you why.

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These bacteria are already[br]in the environment.

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The bacteria in my research[br]are not genetically modified frankenbugs.

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These are naturally occurring bacteria

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that have simply adapted[br]to their plastic-polluted environment

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and evolved the incredibly gnarly[br]ability to eat PET plastic.

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So the process of bacteria eating plastic[br]is actually a natural one.

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But it's an incredibly slow process.

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And there remains a lot of work to be done

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to figure out how to speed up[br]this process to a useful pace.

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My research is currently[br]looking at ways of doing this

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through a series of UV[br]or ultraviolet pretreatments.

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Which basically means[br]we blast PET plastic with sunlight.

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We do this because sunlight[br]acts a bit like tenderizer on a stake,

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turning the big, tough,[br]durable bonds in PET plastic

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a bit softer and a bit easier[br]for my bacteria to chew on.

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Ultimately, what my research hopes to do

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is create an industrial-scale[br]contained carbon-free system,

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similar to a compost heap

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where these bacteria can thrive[br]in a contained system,

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where their sole food source[br]is PET plastic waste.

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Imagine one day being able to dispose[br]of all of your plastic waste

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in a bin at the curb

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that you knew was bound for a dedicated[br]bacteria-powered plastic waste facility.

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I think with some hard work[br]this is an achievable reality.

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Plastic-eating bacteria is not a cure-all.

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But given the current statistics,[br]it's clear that we humans,

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we could use a little help[br]with this problem.

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Because people,

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we possess a pressing problem[br]of plastic pollution.

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And bacteria might be[br]a really important part of the solution.

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Thank you.

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(Applause)