PPlastics are easy to throw away, but hard to get rid of. Unlike biodegradable materials, bacteria and fungi have not evolved the ability to break them down, causing plastic waste to languish for decades and eventually end up in our oceans. AND everywhere more. Now that may change.
According to new research published in ISME MagazineMarine bacteria are beginning to produce enzymes that can break down polyethylene terephthalate (PET), one of the most common plastics. Researchers from institutions in Saudi Arabia and Spain used artificial intelligence and genetic information from a variety of ocean bacteria to identify a pattern of genetic sequence they call the M5 motif, which encodes functional PETases—enzymes that break down PET plastic.
“The M5 motif acts as a fingerprint that tells us when PETase may be functional and capable of degrading PET plastic,” team co-leader Carlos Duarte said in the report. statement. “His discovery helps us understand how these enzymes evolved from other hydrocarbon-degrading enzymes.”
Duarte and his co-authors confirmed that the M5 motif is what distinguishes real PETases from their counterparts in laboratory experiments. The M5 motif was present in nearly 80 percent of the water samples tested, indicating that the likelihood of bacteria developing the ability to feed on plastic is widespread. They reported that bacteria producing functional PETases were found at depths of 3,200 to 6,500 feet and on the ocean surface in areas with high levels of plastic pollution.
Read more: “Will humanity be able to stop the flow of plastic?“
This is good news. With more than 150 million tons of plastic waste in the oceans since 1950, there is plenty of potential food for enterprising bacteria to break it down, according to a study. Meanwhile, the authors say the discovery could help create synthetic PETases for use in recycling.
But the plastic crisis is multifaceted. It is unlikely that the evolution of plastic-degrading microbes will occur at a pace that can keep pace with humanity's production and consumption of plastic.
A report A report released earlier this year, authored by an international team of health researchers, economists and others, estimated that plastic-related health problems cost the world $1.5 trillion annually. “First and foremost, I would like to see some kind of cap or restriction on the global production of new plastics,” Philip Landrigan, lead author of this report and director of the Program on Global Public Health and the Common Good at Boston College and its Global Observatory on Planetary Health, said Nautilus in August. “Even if we stopped production completely today—which of course we won’t—there are 8 billion tons of plastic waste, large and small, circulating in the biosphere.”
These new discoveries offer some ray of hope that the planet's microbes are beginning to adapt to this huge amount of waste and at least begin the process of breaking down some of it.
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Main image: Maxim Safanyuk / Shutterstock
