Scientists: Some types of bacteria eat plastic

European molecular biologists have demonstrated that microbes of the species Rhodococcus ruber are able to break down polyethylene and use the formed hydrocarbon molecules for their life.

A study was published on the subject in the Marine Pollution Bulletin.

“For the first time, we were able to show that microbes can digest plastic, which breaks down into carbon dioxide and other molecules,” said Mike Guderian, a researcher at the Royal Netherlands Marine Institute. Our colleagues have shown in the past that these bacteria can accelerate the degradation of materials, plastics, but we have demonstrated for the first time that these organisms use polymer degradation products in their life.

It is noteworthy that the accumulation of a large amount of plastic waste in the natural environment and in landfills is forcing scientists to look for chemical and biological methods to get rid of them. For example, European biologists have recently discovered that wax moth larvae can eat and digest various forms of polyethylene, while their Japanese colleagues have discovered microbes that can degrade dacron, the material most commonly used in the manufacture of bottles and other plastic utensils.

Goodrian and his colleagues have been studying for years how marine microbes of the species Rhodococcus interact with plastic and how these microbes are able to form films on the surface of microparticles made of polyethylene and other artificial polymeric materials floating in the world’s oceans. These membranes, as recently discovered by oceanologists, accelerate the decomposition of plastic.

European molecular biologists are interested in what exactly happens when bacterial membranes come into contact with microplastics. To answer this question, the researchers prepared polyethylene molecules that contain many of the 13 heavy carbon atoms. Scientists used its particles to track whether biodegradable plastic got into microbes and whether microbes used polyethylene degradation products in their lives.

The researchers placed particles of polyethylene, treated with ultraviolet light to simulate their long stay in water, in a container with colonies of Rhodococcus ruber microbes and observed the change in the carbon-13 content in the microbes and their secretions. Subsequent observations showed that carbon-13 is present both in carbon dioxide molecules produced by microbes and in various components of cell membranes.

This indicates, according to scientists, that Rhodococcus ruber actively decomposes plastic and uses its components in its life. According to current scientists, these microbes could destroy up to 1.2% of the total mass of polyethylene that enters the oceans annually, if environmental conditions were suitable for them.

According to Goodrian and his colleagues, the scientists plan to follow the decomposition of plastic by colonies of Rhodococcus ruber in natural environmental conditions in the near future. The scientists concluded that understanding this is critical to estimating how much plastic has been destroyed by ocean bacteria since the middle of the last century.

Source: TASS