1 00:00:01,542 --> 00:00:05,351 Plastics: you know about them, you may not love them, 2 00:00:05,375 --> 00:00:09,000 but chances are you use them every single day. 3 00:00:10,167 --> 00:00:12,893 By 2050, researchers estimate 4 00:00:12,917 --> 00:00:15,958 that there will be more plastic in the ocean than fish. 5 00:00:17,000 --> 00:00:18,893 Despite our best efforts, 6 00:00:18,917 --> 00:00:24,625 only nine percent of all plastic we use winds up being recycled. 7 00:00:25,417 --> 00:00:26,934 And even worse, 8 00:00:26,958 --> 00:00:29,851 plastic is incredibly tough and durable 9 00:00:29,875 --> 00:00:31,393 and researchers estimate 10 00:00:31,417 --> 00:00:35,518 that it can take anywhere from 500 to 5,000 years 11 00:00:35,542 --> 00:00:37,726 to fully break down. 12 00:00:37,750 --> 00:00:43,268 It leaches harmful chemical contaminants into our oceans, our soil, 13 00:00:43,292 --> 00:00:47,833 our food, our water, and into us. 14 00:00:48,958 --> 00:00:52,601 So how did we wind up with so much plastic waste? 15 00:00:52,625 --> 00:00:54,643 Well, it's simple. 16 00:00:54,667 --> 00:01:00,333 Plastic is cheap, durable, adaptable, and it's everywhere. 17 00:01:00,833 --> 00:01:02,184 But the good news is 18 00:01:02,208 --> 00:01:06,809 there's something else that's cheap, durable, adaptable and everywhere. 19 00:01:06,833 --> 00:01:10,184 And my research shows it may even be able to help us 20 00:01:10,208 --> 00:01:12,333 with our plastic pollution problem. 21 00:01:13,417 --> 00:01:15,875 I'm talking about bacteria. 22 00:01:16,750 --> 00:01:21,643 Bacteria are microscopic living beings invisible to the naked eye 23 00:01:21,667 --> 00:01:23,351 that live everywhere, 24 00:01:23,375 --> 00:01:26,601 in all sorts of diverse and extreme environments, 25 00:01:26,625 --> 00:01:30,226 from the human gut, to soil, to skin, 26 00:01:30,250 --> 00:01:34,768 to vents in the ocean floor, reaching temperatures of 700 degrees Fahrenheit. 27 00:01:34,792 --> 00:01:37,059 Bacteria live everywhere, 28 00:01:37,083 --> 00:01:40,268 in all sorts of diverse and extreme environments. 29 00:01:40,292 --> 00:01:44,833 And as such, they have to get pretty creative with their food sources. 30 00:01:46,000 --> 00:01:48,101 There's also a lot of them. 31 00:01:48,125 --> 00:01:53,184 Researchers estimate that there are roughly five million trillion trillion -- 32 00:01:53,208 --> 00:01:58,542 that's a five with 30 zeros after it -- bacteria on the planet. 33 00:01:59,625 --> 00:02:02,976 Now, considering that we humans produce 34 00:02:03,000 --> 00:02:07,393 300 million tons of new plastic each year, 35 00:02:07,417 --> 00:02:09,934 I'd say that our plastic numbers 36 00:02:09,958 --> 00:02:12,667 are looking pretty comparable to bacteria's. 37 00:02:13,833 --> 00:02:16,309 So, after noticing this 38 00:02:16,333 --> 00:02:18,643 and after learning about all of the creative ways 39 00:02:18,667 --> 00:02:20,684 that bacteria find food, 40 00:02:20,708 --> 00:02:22,893 I started to think: 41 00:02:22,917 --> 00:02:25,809 could bacteria in plastic-polluted environments 42 00:02:25,833 --> 00:02:29,250 have figured out how to use plastic for food? 43 00:02:30,375 --> 00:02:35,309 Well, this is the question that I decided to pursue a couple of years ago. 44 00:02:35,333 --> 00:02:37,351 Now, fortunately for me, 45 00:02:37,375 --> 00:02:40,518 I'm from one of the most polluted cities in America, 46 00:02:40,542 --> 00:02:42,393 Houston, Texas. 47 00:02:42,417 --> 00:02:43,601 (Laughs) 48 00:02:43,625 --> 00:02:44,893 In my hometown alone, 49 00:02:44,917 --> 00:02:48,792 there are seven EPA-designated Superfund sites. 50 00:02:50,208 --> 00:02:52,768 These are sites that are so polluted, 51 00:02:52,792 --> 00:02:56,917 that the government has deemed their cleanup a national priority. 52 00:02:58,250 --> 00:03:01,309 So I decided to trek around to these sites 53 00:03:01,333 --> 00:03:04,684 and collect soil samples teeming with bacteria. 54 00:03:04,708 --> 00:03:07,018 I started toying with a protocol, 55 00:03:07,042 --> 00:03:10,101 which is fancy science talk for a recipe. 56 00:03:10,125 --> 00:03:14,309 And what I was trying to cook up was a carbon-free media, 57 00:03:14,333 --> 00:03:17,101 or a food-free environment. 58 00:03:17,125 --> 00:03:19,934 An environment without the usual carbons, or food, 59 00:03:19,958 --> 00:03:23,000 that bacteria, like us humans, need to live. 60 00:03:24,083 --> 00:03:25,351 Now, in this environment, 61 00:03:25,375 --> 00:03:29,208 I would provide my bacteria with a sole carbon, or food, source. 62 00:03:30,042 --> 00:03:34,393 I would feed my bacteria polyethylene terephthalate, 63 00:03:34,417 --> 00:03:36,708 or PET plastic. 64 00:03:37,917 --> 00:03:42,934 PET plastic is the most widely produced plastic in the world. 65 00:03:42,958 --> 00:03:46,018 It's used in all sorts of food and drink containers, 66 00:03:46,042 --> 00:03:50,018 with the most notorious example being plastic water bottles, 67 00:03:50,042 --> 00:03:55,708 of which we humans currently go through at a rate of one million per minute. 68 00:03:58,042 --> 00:04:00,268 So, what I would be doing, 69 00:04:00,292 --> 00:04:05,184 is essentially putting my bacteria on a forced diet of PET plastic 70 00:04:05,208 --> 00:04:09,750 and seeing which, if any, might survive or, hopefully, thrive. 71 00:04:11,000 --> 00:04:13,518 See, this type of experiment would act as a screen 72 00:04:13,542 --> 00:04:17,517 for bacteria that had adapted to their plastic-polluted environment 73 00:04:17,541 --> 00:04:22,208 and evolved the incredibly cool ability to eat PET plastic. 74 00:04:23,167 --> 00:04:24,809 And using this screen, 75 00:04:24,833 --> 00:04:28,500 I was able to find some bacteria that had done just that. 76 00:04:29,375 --> 00:04:34,125 These bacteria had figured out how to eat PET plastic. 77 00:04:36,583 --> 00:04:38,750 So how do these bacteria do this? 78 00:04:39,583 --> 00:04:42,351 Well, it's actually pretty simple. 79 00:04:42,375 --> 00:04:46,434 Just as we humans digest carbon or food into chunks of sugar 80 00:04:46,458 --> 00:04:48,309 that we then use for energy, 81 00:04:48,333 --> 00:04:50,250 so too do my bacteria. 82 00:04:51,375 --> 00:04:55,726 My bacteria, however, have figured out how to do this digestion process 83 00:04:55,750 --> 00:04:58,875 to big, tough, durable PET plastic. 84 00:05:00,292 --> 00:05:03,059 Now, to do this, my bacteria use a special version 85 00:05:03,083 --> 00:05:05,143 of what's called an enzyme. 86 00:05:05,167 --> 00:05:09,476 Now, enzymes are simply compounds that exist in all living things. 87 00:05:09,500 --> 00:05:11,518 There are many different types of enzymes, 88 00:05:11,542 --> 00:05:14,684 but basically, they make processes go forward, 89 00:05:14,708 --> 00:05:17,375 such as the digestion of food into energy. 90 00:05:18,417 --> 00:05:21,851 For instance, we humans have an enzyme called an amylase 91 00:05:21,875 --> 00:05:25,518 that helps us digest complex starches, such as bread, 92 00:05:25,542 --> 00:05:28,958 into small chunks of sugar that we can then use for energy. 93 00:05:30,042 --> 00:05:33,934 Now, my bacteria have a special enzyme called a lipase 94 00:05:33,958 --> 00:05:37,643 that binds to big, tough, durable PET plastic 95 00:05:37,667 --> 00:05:40,351 and helps break it into small chunks of sugar 96 00:05:40,375 --> 00:05:43,083 that my bacteria can then use for energy. 97 00:05:44,250 --> 00:05:45,518 So basically, 98 00:05:45,542 --> 00:05:50,184 PET plastic goes from being a big, tough, long-lasting pollutant 99 00:05:50,208 --> 00:05:52,542 to a tasty meal for my bacteria. 100 00:05:54,958 --> 00:05:56,667 Sounds pretty cool, right? 101 00:05:58,458 --> 00:06:03,059 And I think, given the current scope of our plastic pollution problem, 102 00:06:03,083 --> 00:06:04,917 I think it sounds pretty useful. 103 00:06:06,250 --> 00:06:08,018 The statistics I shared with you 104 00:06:08,042 --> 00:06:12,393 on just how much plastic waste has accumulated on our planet 105 00:06:12,417 --> 00:06:13,934 are daunting. 106 00:06:13,958 --> 00:06:15,643 They're scary. 107 00:06:15,667 --> 00:06:17,143 And I think they highlight 108 00:06:17,167 --> 00:06:21,476 that while reducing, reusing and recycling are important, 109 00:06:21,500 --> 00:06:25,167 they alone are not going to be enough to solve this problem. 110 00:06:26,417 --> 00:06:30,875 And this is where I think bacteria might be able to help us out. 111 00:06:31,750 --> 00:06:35,518 But I do understand why the concept of bacterial help 112 00:06:35,542 --> 00:06:38,476 might make some people a little nervous. 113 00:06:38,500 --> 00:06:44,059 After all, if plastic is everywhere and these bacteria eat plastic, 114 00:06:44,083 --> 00:06:47,268 isn't there a risk of these bacteria getting out in the environment 115 00:06:47,292 --> 00:06:48,625 and wreaking havoc? 116 00:06:50,292 --> 00:06:54,143 Well, the short answer is no, and I'll tell you why. 117 00:06:54,167 --> 00:06:57,542 These bacteria are already in the environment. 118 00:06:58,375 --> 00:07:02,625 The bacteria in my research are not genetically modified frankenbugs. 119 00:07:04,250 --> 00:07:06,559 These are naturally occurring bacteria 120 00:07:06,583 --> 00:07:10,351 that have simply adapted to their plastic-polluted environment 121 00:07:10,375 --> 00:07:15,083 and evolved the incredibly gnarly ability to eat PET plastic. 122 00:07:16,167 --> 00:07:21,601 So the process of bacteria eating plastic is actually a natural one. 123 00:07:21,625 --> 00:07:24,434 But it's an incredibly slow process. 124 00:07:24,458 --> 00:07:26,934 And there remains a lot of work to be done 125 00:07:26,958 --> 00:07:30,833 to figure out how to speed up this process to a useful pace. 126 00:07:32,000 --> 00:07:34,726 My research is currently looking at ways of doing this 127 00:07:34,750 --> 00:07:38,851 through a series of UV, or ultraviolet, pretreatments, 128 00:07:38,875 --> 00:07:42,750 which basically means we blast PET plastic with sunlight. 129 00:07:44,292 --> 00:07:48,893 We do this because sunlight acts a bit like tenderizer on a steak, 130 00:07:48,917 --> 00:07:52,893 turning the big, tough, durable bonds in PET plastic 131 00:07:52,917 --> 00:07:56,875 a bit softer and a bit easier for my bacteria to chew on. 132 00:07:58,208 --> 00:08:00,684 Ultimately, what my research hopes to do 133 00:08:00,708 --> 00:08:05,309 is create an industrial-scale contained carbon-free system, 134 00:08:05,333 --> 00:08:07,559 similar to a compost heap, 135 00:08:07,583 --> 00:08:11,184 where these bacteria can thrive in a contained system, 136 00:08:11,208 --> 00:08:15,375 where their sole food source is PET plastic waste. 137 00:08:16,458 --> 00:08:21,143 Imagine one day being able to dispose of all of your plastic waste 138 00:08:21,167 --> 00:08:22,601 in a bin at the curb 139 00:08:22,625 --> 00:08:28,375 that you knew was bound for a dedicated bacteria-powered plastic waste facility. 140 00:08:29,542 --> 00:08:34,332 I think with some hard work this is an achievable reality. 141 00:08:35,250 --> 00:08:38,643 Plastic-eating bacteria is not a cure-all. 142 00:08:38,667 --> 00:08:42,933 But given the current statistics, it's clear that we humans, 143 00:08:42,957 --> 00:08:45,458 we could use a little help with this problem. 144 00:08:46,292 --> 00:08:47,559 Because people, 145 00:08:47,583 --> 00:08:51,268 we possess a pressing problem of plastic pollution. 146 00:08:51,292 --> 00:08:55,726 And bacteria might be a really important part of the solution. 147 00:08:55,750 --> 00:08:57,018 Thank you. 148 00:08:57,042 --> 00:09:00,000 (Applause)