Science TED Conferences

A local bacteria to solve a local problem: Miranda Wang and Jeanny Yao at TED2013

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Photo: James Duncan Davidson

Photo: James Duncan Davidson

Miranda Wang and Jeanny Yao were the winners in British Columbia of the 2012 Sanofi BioGENEius Challenge Canada. After a visit to a Vancouver waste station, Wang and Yao were blown away by the enormous amount of waste in plastic. Plastic is very hard to sort for recycling — all types have a similar density. Says Wang, “Plastics are useful, but the downside of this convenience is that plastics cause serious problems like the destruction of ecosystems.”

So Wang and Yao decided to see if there was a way to break them down … with bacteria! It’s a cool idea, but difficult. They made a proposal in grade 12: Find a bacteria from local river to metabolize phthalates. Phthalates are a component of plastic, but they’re not well bonded, so they easily pollute and are found in products like babies’ toys, cosmetics, food wraps. In fact, the EPA has classified them as a top-priority pollutant.

Wang and Yao figured that if there were places along the local river that were contaminated, then maybe bacteria have evolved to degrade them. So they met a professor who gave them lab space and set to work. They collected samples from three sites, and enriched cultures with phthalates as the only food source. And they discovered that “bacteria can do it” — several local species had indeed evolved to metabolize phthalates. They DNA-sequenced the bacteria, and found several that were not previously associated with phthalate degradation. That’s a real discovery.

Most interestingly, Wang says, “We found the most efficient degraders came from the local landfill.” Nature was indeed evolving ways of dealing with the problem, one that we could someday use. Yao finishes by noting, “We weren’t the first ones to break down phthalates, but we were the first ones to look into our local river and find a possible solution to a local problem.”