lundi 31 mai 2010

Un étudiant de 16 ans découvre des bactéries consommant du plastique

Comme quoi les découvertes les plus importantes, sont rarement l'affaire des 'experts'...


Boy discovers microbe that eats plastic

PhDs have been searching for a solution to the plastic waste problem, and this 16-year-old finds the answer.


Photo: Samuel Mann/Flickr
It's not your average science fair when the 16-year-old winner manages to solve a global waste crisis. But such was the case at last May's Canadian Science Fair in Waterloo, Ontario, where Daniel Burd, a high school student at Waterloo Collegiate Institute, presented his research on microorganisms that can rapidly biodegrade plastic.
NOTE: There are TWO high school students who discovered plastic-consuming microorganisms. The first was Daniel Burd. The second was Tseng I-Ching (last month), a high school student in Taiwan.
Daniel had a thought it seems even the most esteemed PhDs hadn't considered. Plastic, one of the most indestructible of manufactured materials, does in fact eventually decompose. It takes 1,000 years but decompose it does, which means there must be microorganisms out there to do the decomposing.
Could those microorganisms be bred to do the job faster?
That was Daniel's question, and he put to the test with a very simple and clever process of immersing ground plastic in a yeast solution that encourages microbial growth, and then isolating the most productive organisms.
The preliminary results were encouraging, so he kept at it, selecting out the most effective strains and interbreeding them. After several weeks of tweaking and optimizing temperatures Burd was achieved a 43 percent degradation of plastic in six weeks, an almost inconceivable accomplishment.
With 500 billion plastic bags manufactured each year and a Pacific Ocean Garbage Patch that grows more expansive by the day, a low-cost and nontoxic method for degrading plastic is the stuff of environmentalists' dreams and, I would hazard a guess, a pretty good start-up company as well.
NOTE to the comment below: Yes there are certainly methods for decomposing plastic, but most are chemical in nature not organic, requiring high temperatures and chemical additives to cause the plasticizers to vaporize, for instance this patenton PVC extraction. There have been several successful bacteria-based solutions developed at the Department of Biotechnology in Tottori, Japan as well as the Department of Microbiology at the National University of Ireland, but both apply only to styrene compounds.
It goes without saying that these discoveries need to be tested to ensure, for instance, that the byproducts of organic decomposition are not carcinogenic (as in the case with mammalian metabolism of styrene and benzene). The processing of plastics by these methods would also have to be contained in highly controlled environments. So, no, we're not talking about a magic panacea or a plastic-free paradise, but the innovative application of microorganisms to break down our most troublesome waste products is nevertheless a major scientific breakthrough.
NOTE: One of our readers pointed out a very interesting study in 2004 at the University of Wisconsin that isolated a fungus capable of biodegrading phenol-formaldehyde polymers previously thought to be non-biodegradable. Phenol polymers are produced at an annual rate of 2.2 million metric tons per year in the United States for many industrial and commercial applications including durable plastics.
COMMENTS: This story has generated a flurry of feedback since it was posted on June 12. Here's a compilation of the best and brightest comments.


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