Our oceans already contain a lot of plastic, and scientists have found an enzyme that enables bacteria to break it down and digest it.
Researchers at King Abdullah University of Science and Technology have conducted a new study that demonstrates the prevalence of these bacteria and the mechanism by which they degrade PET, or polyethylene terephthalate, a common plastic used in polyester, packaging, and other products.
Nearly 80 per cent of the 415 ocean samples examined in the study, published in ISME Journal, contained PETase, an enzyme that breaks down PET, which was identified by the M5 motif.
Carlos Duarte, a marine ecologist who co-led the study, said, "The M5 motif acts like a fingerprint that tells us when a PETase is likely to be functional, able to break down PET plastic. Its discovery helps us understand how these enzymes evolved from other hydrocarbon-degrading enzymes. In the ocean, where carbon is scarce, microbes seem to have fine-tuned these enzymes to make use of this new, human-made carbon source: plastic."
According to him, these enzymes are an evolutionary reaction to the plastic debris that has been washing up in the ocean since the 1950s. Since its introduction more than 70 years ago, plastic litter has been accumulating both on land and at sea and worries about its effects on ocean ecosystems have grown along with it.
Plastic pollution has an impact on human health in addition to causing problems for the environment and our planet. Everything from our food and water to our blood and brains contains microplastics, which increase the risk of several illnesses like asthma and cardiovascular disease.
Scientists were unsure of the prevalence of these enzymes and did not think PET could be broken down naturally until 2016. These discoveries give us great hope for both the disposal of plastic waste and the tons of plastic debris that are currently floating in our oceans.
"The range of PET-degrading enzymes spontaneously evolved in the deep sea provides models to be optimized in the lab for use in efficiently degrading plastics in treatment plants and, eventually, at home," Duarte said.
PETase enzymes may offer a solution to the issues plastic causes after use, but the manufacturing of these products also puts people and the environment at serious risk. Protecting individuals, communities, and the environment still depends on lowering the production and consumption of plastic and disposing of it according to best practices.
