Plastic is Good Eatin’ to some Bacteria!
Plastic can be biodegradable in the presence of a certain kind of bacteria. A microbiologist at the Kyoto Institute in Japan and his team of researchers found that a certain kind bacteria can feast on the most common form of plastic known as PET, a polymer widely used in plastic bottles, as its main source of energy.
At a recycling plant, Dr. Yoshida and his team collected 250 samples of PET debris and discovered a host of different microbes living among the trash. The researchers screened the microbes to identify those that appeared to dine on PET, and subsequent testing showed that a single, new species, Ideonella sakaiensis, was responsible for decomposing the polymer.
Around 56 million tons of PET were produced in 2013 alone, but only around half of the material is ever recycled. And the qualities that make PET attractive to companies — its durability and resistance to water — also make it a danger to the environment. PET takes a long time to biodegrade, and so it accumulates in landfills and the ocean. It’s thought that plastic bottles take 450 years to break down, and although some plastics do degrade quicker in the ocean, this just leads to more chemical pollution.
Dr. Yoshida said a colony of I. sakaiensis could completely degrade a low-grade plastic water bottle in six weeks. But, because most bottles are made of higher-grade PET, Yoshida said the plastic would need to be heated and cooled—cooking the bacteria’s dinner, in effect—to weaken it before bacteria could start eating.
A biotechnology professor, Uwe Bornscheue, said that the bacterium could in theory be added to landfills to speed decomposition. “The rate of degradation is rather slow, but it works,” he told a publication” adding, “this should be improved by further studies on this strain.”