Scientists have identified a bacterium in a plastic landfill that can degrade polyurethane. This could be a step towards large-scale recycling of plastic waste, which is now difficult to recycle. However, according to experts, the industrial use of the bacteria will not be possible soon.
Scientists have discovered a bacterium that feeds on toxic plastic. She not only decomposes it, but also uses it for food.
She was found in a garbage dump where plastic is taken. It is the first bacteria to degrade polyurethane. Millions of tons of plastic are produced each year and are used to make sports shoes, diapers, kitchen sponges and foam insulation. But mostly it is not disposed of, but sent to a landfill, because it is very difficult to recycle plastic.
When plastic decomposes, toxic and carcinogenic substances are formed that kill most bacteria, but a recently discovered strain is resistant to such effects. Scientists have identified the type of microorganism and some of its key characteristics, but they still have a lot of work to be done before this bacteria can be used to process large quantities of plastic waste.
“This discovery was an important step towards recycling polyurethane products that are difficult to process,” said research team member Hermann Heipieper of the Helmholtz Society's Environmental Research Center in Germany. It may take 10 years before the bacteria can be used commercially, he said, during which time it is imperative to reduce the use of plastic, which is difficult to recycle, and to reduce the amount of plastic in the environment.
Since the 1950s, the world has produced more than eight billion tons of plastic, and most of it today pollutes land and the world's oceans, and is also buried in landfills. Scientists say plastic can poison the natural environment forever.
These studies are published in the journal Frontiers in Microbiology. In the course of its conduct, scientists have identified a new strain of the bacteria Pseudomonas aeruginosa (Pseudomonas). This type of bacteria is able to survive in extremely unfavorable conditions of high temperatures and acidic environment.
Scientists in the lab fed her the key chemicals in polyurethane. “We found that the bacteria uses these substances as their sole source of carbon, nitrogen and energy,” said Hypeper.
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Previously, different types of fungus were used to decompose polyurethane, but in industry the bacteria are much easier to use. Hypiper said the next step will be to identify genes for enzymes produced by bacteria that break down polyurethane.
Scientists said that in 2018, they accidentally created a mutant enzyme that degrades plastic terephthalate bottles. This made it possible for the first time to engage in the processing of such containers. This new work was praised by Professor John McGeehan, Director of the Center for Enzyme Innovation at the University of Portsmouth in England.
“The decomposition of certain polyurethanes can lead to the release of toxic substances, which must be handled with great care. This research team has discovered a strain that can deal with some of these substances, he said. - There is still a lot of work to be done, but this is a wonderful and necessary study showing that one must turn to nature in search of valuable biocatalysts. Understanding and mastering such natural processes will open the door to innovative solutions to the problems of disposal and recycling."
Hypeper said: “When there is a huge amount of plastic in the environment, it means there will be a lot of carbon and that it will be used as food in the process of evolution. Bacteria are abundant and they evolve very quickly."
“But that in no way means that the work of microbiologists will completely solve the problem,” he continued. "The main thing is not to throw away plastic or pollute the environment with it."
Previous studies have also shown that some fungi can degrade PET plastic, and the larvae of the moth (wax moth) used to feed the fish eat plastic bags.
Damian Carrington