Plastic-eating bacteria are more common than previously thought
The introduction of plastic waste into the environment poses a massive problem, also because the microparticles accumulate in numerous living things and thus enter the food chain. Fundamentally, new approaches to recycling are just as important here as the consideration of material recycling in the context of production and waste prevention. Existing loads must also be reduced. Plastic-eating bacteria could help here, and according to a recent study there are far more than previously thought.
"Plastics such as PET (polyethylene terephalate), from which bottles or packaging are made, are only recycled to a small extent, the majority are released into the environment," warn scientists from the University of Hamburg. Hope for an accelerated degradation aroused about two years ago the discovery of a bacterium that attacks and decomposes plastic. Researchers at the University of Hamburg have now been able to prove that there are far more plastic-eating bacteria than previously thought. Her study results were published in the specialist journal "Applied and Environmental Microbiology".
A plastic bottle has only decomposed after 450 years
In the environment, the plastics are broken down very slowly and accordingly there is an increasing accumulation, which also affects us humans via the food chain. It takes up to 450 years for a plastic bottle to dissolve, reports the University of Hamburg, citing the Federal Environment Agency. Plastic-eating bacteria could potentially accelerate this process.
Many types of bacteria are responsible for plastic degradation
The research team led by Prof. Dr. Wolfgang Streit from the Biozentrum Klein Flottbek at the University of Hamburg went in search of such bacteria and analyzed the genetic makeup of bacteria from different habitats on land and in the water. The evaluation using global databases showed "that many bacteria can be partly responsible for the breakdown of PET and that the bacteria involved are more diverse in their phylogenetic development than previously assumed," said the university.
In principle, degradation is very slow
As part of their study, the scientists examined the degradation products that are created in the bacteria when the plastic is degraded and the enzymes involved. According to their own statements, they discovered "several hundred novel enzymes, the so-called PET hydrolases", which obviously play a decisive role. "We were surprised that the types of bacteria involved are much more diverse than previously thought," emphasizes Prof. Streit. The characterization of four selected PET hydrolases now presented further the understanding of the degradation mechanisms. However, it was also confirmed that "the degradation of PET by the bacteria is in principle very slow"; the director of studies continues. (fp)