Marine microbes biodegrade and consume polyurethane foam

Plastics, which are already ubiquitous around the world, pose a major challenge to human health and the environment. Evidence of plastic pollution can be found globally, from grocery bags in the deep sea to microplastics in food supplies and even in human blood.

Polyurethane foam biodegrades after 1 month in a seawater tank. Image Credit: Daniel Zhen, Algenesis Inc.

To solve the growing problem of plastic pollution, researchers at University of California, San Diego They have created new biodegradable polymers that are intended to replace traditionally used plastics.

An interdisciplinary team of researchers led by UCSD biologist Steven Mayfield and chemists Michael Burkart and Robert “Skip” Pomeroy recently demonstrated that polyurethane foams dissolve in seawater after they demonstrated for the first time the biodegradation of the material in ground compost.

The results have been published in college ecology magazine.

Scientists are trying to tackle the problem of plastic pollution, which is currently being referred to as a global environmental disaster. In 2010, scientists predicted that 8 billion kilograms of plastic will enter the ocean annually, and that this number will increase sharply by 2025.

Plastic waste disturbs marine ecosystems once it enters the water, moves to strategic areas, and forms garbage eddies like the Great Pacific Garbage Patch, which is more than 1.6 million kilometers in length.2.

These plastics never degrade; Instead, they are broken down into smaller pieces to become microplastics, which linger in the environment for centuries.

Scientists at the University of San Diego conducted experiments with biodegradable polyurethane materials at the Ellen Browning Scripps Memorial Pier and Scripps Experimental Aquarium under the direction of Samantha Clements, study co-author and a marine biologist and science diver at the Scripps Institution of Oceanography.

The location of the pier gave the researchers access to and a unique opportunity to test the material in the near-shore environment, which is where rogue plastics are most likely to end up.

The scientists discovered that various marine organisms colonized the polyurethane foam and biodegraded the material into starting chemicals.

These primary chemicals were ingested by these microbes in the ocean environment. Research data indicates that microbes, a mixture of fungi and bacteria, thrive throughout the natural marine environment.

Improper disposal of plastic in the ocean degrades into microplastic particles and has become a massive environmental problem. We have shown that it is entirely possible to make high-performance plastic products that can also degrade in the ocean.

Stephen Mayfield, Professor, College of Biological Sciences, Director of the California Center for Algae Biotechnology

“The plastic shouldn’t go into the ocean in the first place, but if it does, that substance becomes food for microorganisms and not plastic waste and microplastics that are harmful to aquatic life,Mayfield continued.

High-heeled shoes, the most popular shoes all over the world, and other shoes account for a large portion of the plastic garbage that is dumped in landfills and oceans around the world.

The project brought together professionals in polymers, synthetic chemistry, biology, marine sciences and other fields to test and analyze polyurethane materials created at UCSD over the past eight years.

Foam samples were subjected to tidal and wave dynamics, and chemical and physical changes were monitored using electron microscopy and infrared spectroscopy.

The results showed that the material began to deteriorate within four weeks. The scientists then discovered microbes from six marine sites in San Diego that could degrade and consume polyurethane.

There is no single system that can address these global environmental problems but we have developed an integrated solution that works on land – and now we also know of biodegradation in the ocean. I was surprised to see how many organisms colonize on these foams in the ocean. It becomes something like a microbial coral.

Stephen Mayfield, Professor, College of Biological Sciences, Director of the California Center for Algae Biotechnology

Co-authors are Natasha Gunawan, Marissa Tesman, Daniel Zinn, Lindsey Johnson, Payton Evans, Samantha Clements, Robert Pomeroy, Michael Burkhart, Ryan Simkowski and Stephen Mayfield. The study was supported by a US Department of Energy grant (DE-SC0019986) to Algenesis Inc.

magazine reference

Gunawan, N.R., and others. (2022) Biodegradation of renewable polyurethane foam occurs in marine environments through depolymerization by marine microorganisms.. college ecology. doi.org/10.1016/j.scitotenv.2022.158761.

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