Since its widespread use in the 1950s, plastic has been known to cause environmental concerns and a potential threat to human health. From 1950 - 2017, around 9.2 billion tonnes of plastic were produced, and according to the UN Environment Programme, 7 billion tonnes of it ended up in landfills or dumped.
Today, our planet faces a global plastics crisis, and an immediate solution is needed for proper management and resource recovery of plastic products. Several approaches and strategies have been employed to utilize the beneficial use of plastics without creating environmental waste challenges.
Seeking the Help of Microorganisms
A group of researchers from the Swiss Federal Institute for Forest, Snow, and Landscape Research WSL has discovered a type of bacteria and fungi that can deteriorate plastic materials at cool temperatures.
Scientists are already familiar with several microbes that can eat up plastic. However, most known microbes need at least 30 degrees Celsius to decompose. This temperature requirement leads to more energy- and financially-intensive recycling process. A new microbe decomposed plastics as cold as 15 degrees Celsius.
In this study, the researchers buried plastic in soil from the Alps and Greenland. Over several months, they observed the growth of bacteria and fungi on the plastic materials. The discovered microbes were taken one year after the plastic pieces were buried. They underwent further testing in the laboratory to determine their ability to degrade various types of plastics. Nineteen strains of cold-adapted microbes were found to produce enzymes that help them break down some plastics. However, they can only decompose biodegradable plastics, and none of the microbes can degrade plastic polyethylene (PE) materials.
If this process is expanded to industry, it could make the decomposition process more efficient. This discovery can open up a new perspective for plastic recycling as it could be the key to helping reduce much of the plastic waste on Earth. However, scientists believe that a lot of work still needs to be done.
Research co-author Beat Frey reported, "The next big challenge will be to identify the plastic-degrading enzymes produced by the microbes and to optimize the process to obtain large amounts of enzymes."
READ ALSO : Newly invented bacteria eats plastic
A Different Kind of Appetite
Most bacteria prefer to eat sugar which they break down to provide energy for their growth. However, some bacteria strains have an appetite for complex waste from plants and plastic products.
An example of this is Comamonas testosterone is found to digest synthetic laundry detergents, and scientists studied their ability to break down compounds from plastic products and woody waste from plants known as fibrin.
In Japan, scientists discovered the bacteria Ideonella sakaiensis at a bottle recycling facility in Osaka. This type of bacteria was found to decompose plastic products made from polyethylene terephthalate (PET).
Still, these types of plastic-eating bacteria cannot digest the materials fast enough to reduce the tens of millions of tons of waste disposed of in the environment every year. Scientists believe that large-scale commercial use of these organisms might still be years away, and they are looking for the practicality of releasing them into the environment as a potential solution to the global plastic waste challenge.
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