Are plasticizing bacteria a solution to environmental problems?

Plastic-eating bacteria are more widespread than previously thought

The introduction of plastic waste into the environment is a massive problem, also because the microparticles in numerous organisms suffice and thus enter the food chain. As a matter of principle, new approaches to recycling are just as much in demand here, as is the consideration of material recycling as part of production and waste prevention. Existing loads must also be reduced. This could help plasticizing bacteria, of which, according to a recent study, there is much more than previously thought.

"Plastics such as PET (polyethylene terephthalate), from which bottles or packaging are made, are only recycled to a small extent, the majority are released into the environment," say scientists at the University of Hamburg. Hope for accelerated degradation sparked the discovery of a bacterium that attacks and decomposes plastic about two years ago. Now, researchers from the University of Hamburg were able to prove that far more plastic-eating bacteria exist than previously thought. Their study results were published in the journal "Applied and Environmental Microbiology".

Plastic waste is a massive environmental problem. Plastic-eating bacteria degrade plastics and could reduce stress. (Image: kranidi / fotolia.com)

A plastic bottle is only decomposed after 450 years

In the environment, the plastics are degraded only very slowly and accordingly there is an increasing enrichment, which affects us humans through the food chain. It takes up to 450 years for a plastic bottle to dissolve, reports the University of Hamburg, citing the Federal Environmental Agency. Plastic-eating bacteria could potentially accelerate this process.

Many types of bacteria responsible for plastic degradation

The research team around Prof. Dr. med. Wolfgang Streit from the Biozentrum Klein Flottbek at the University of Hamburg has gone on the search for such bacteria and analyzed the genetic material of bacteria from different habitats on land and in the water. The evaluation with the aid of global databases showed "that many bacteria can be jointly responsible for the degradation of PET and that the bacteria involved are more diverse in their phylogenetic development than previously assumed," the University's announcement said.

Degradation takes place very slowly

As part of their study, the scientists investigated the degradation products that are formed in the bacteria during degradation of the plastic and the enzymes involved. They discovered "several hundred novel enzymes, the so-called PET hydrolases", which obviously play a crucial role. "We were surprised that the bacterial species involved are much more diverse than previously assumed," emphasizes Prof. Streit. The now presented characterization of four selected PET hydrolases extends the understanding of the degradation mechanisms. However, it has also been confirmed "that the degradation of PET by the bacteria is in principle very slow"; the study director continues. (Fp)