[ti:New Plastic-Eating Substance May Help Fight Against Pollution] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.24]Scientists in Britain and the United States have designed a substance that eats plastic. [00:08.93]They believe that, in the future, it could help reduce pollution. [00:16.04]The enzyme is able to break down polyethylene terephthalate, or PET. [00:24.64]This form of plastic was patented in the 1940s. [00:30.04]It is now used in millions of metric tons of plastic bottles. [00:36.60]PET plastics can remain in the environment for hundreds of years. [00:43.44]The plastics pollute large areas of land and water around the world. [00:50.13]Researchers from Britain's University of Portsmouth and the U.S. Department [00:56.90]of Energy's National Renewable Energy Laboratory made the discovery. [01:03.32]They did so while examining the structure of a natural enzyme [01:08.48]that is thought to have evolved in a waste recycling center in Japan. [01:14.64]John McGeehan, a professor at Portsmouth, co-led the work. [01:20.88]He said the researchers found that the natural enzyme [01:25.28]was helping a bacteria break down PET plastic. [01:31.00]So, the researchers decided to make small changes [01:35.68]to its structure by adding some amino acids. [01:40.88]This led to a valuable change in the enzyme's actions. [01:46.40]It made the enzyme's plastic-eating abilities work more quickly. [01:52.76]"We've made an improved version of the enzyme [01:56.51]better than the natural one already," McGeehan told the Reuters news service. [02:03.08]He added that it may be possible for them [02:06.28]to make more improvements to it in the future. [02:09.88]The journal Proceedings of the National Academy of Sciences [02:16.02]published the team's findings earlier this month. [02:19.60]The team is now trying to make it possible for the enzyme [02:25.17]to be able to break down much larger amounts of PET plastics. [02:32.16]McGeehan said, "It's well within the possibility that, in the coming years, [02:38.04]we will see an industrially viable process to turn PET, and potentially other (plastics), [02:46.72]back into their original building blocks so that they can be sustainably recycled." [02:54.04]Independent scientists not directly involved [02:57.72]with the research said the discovery was interesting. [03:02.32]But they warned that the enzyme's development [03:05.64]as a possible solution for pollution was still in the early stages. [03:11.92]Oliver Jones is a chemistry expert at the Royal Melbourne Institute of Technology University. [03:20.32]He told Reuters that enzymes are not harmful to humans and other animals. [03:26.96]They easily break down in natural conditions. [03:31.32]Also, extremely small organisms can produce them in large amounts. [03:38.56]"There is strong potential to use enzyme technology to help with society's growing waste problem [03:46.12]by breaking down some of the most commonly used plastics," Jones said. [03:53.16]Douglas Kell is a professor of biological science at Manchester University. [03:59.92]He said further rounds of work "should be expected to improve the enzyme yet further." [04:07.84]He added that the discovery brings the goal of creating manmade, [04:13.24]sustainably recyclable chemical substances much closer to reality. [04:19.52]I'm -Pete Musto. 更多听力请访问51VOA.COM