Surprising study shows microbes are evolving to degrade plastic on land and oceans

By : Dr. Franyi Sarmiento, Ph.D., Inspenet, March 30, 2022.

New research from a team at Chalmers University of Technology in Sweden revealed that there are 30,000 different enzymes developed by microorganisms that can break down up to 10 types of everyday plastics.

The researchers analyzed environmental DNA samples obtained from hundreds of ocean and land locations around the world, using computer models to detect microbial enzymes with the potential to break down plastics.

It turned out that some of the places with the most enzymes were the most polluted areas, such as the Mediterranean Sea and the South Pacific Ocean.

“Using our models, we found multiple lines of evidence supporting the fact that the global microbiome’s plastic degradation potential correlates strongly with measurements of environmental plastic pollution, a significant demonstration of how the environment is responding to pressures. that we are exerting on him,” Aleksej Zelezniak, an author of the study, told New Atlas.

Other noteworthy findings are that the enzymes are distributed both on land and in the oceans, and higher concentrations of degrading enzymes were found in deeper ocean areas, indicating a connection between higher concentrations of microplastics that have been observed at these depths.

“Currently, very little is known about these plastic-degrading enzymes, and we did not expect to find such a large number of them in so many different microbes and environmental habitats. This is a surprising discovery that really illustrates the magnitude of the problem”, explained Jan Zrimec, another of the authors.

Around eight million tons are dumped into the ocean each year, this has given microbes a considerable window to develop certain evolutionary responses to survive in the midst of so much garbage.

Soil samples were collected from 169 locations in 38 countries and 11 habitats, yielding 18,000 plastic-degrading enzymes. The scientists concluded that enzyme counts were higher in soil samples than in ocean samples because soils contain more plastics with phthalate additives, which the new enzymes attack.

According to the research, nearly 60% of the enzymes found did not fit into any known enzyme class, necessitating further investigation.

“The next step would be to test the most promising candidate enzymes in the lab to closely investigate their properties and the rate of plastic degradation they can achieve,” added Zelezniak. “From there, we could design microbial communities with specific degradation functions for specific polymers.”

The research was published in the mBio journal at https://journals.asm.org/doi/10.1128/mBio.02155-21

Source : https://www.lr21.com.uy/tecnologia/1454389-microbios-de-la-tierra-y-el-oceano-estan-evolucionando-para-degradar-el-plastico

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