Posts Tagged ‘enzyme’

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Scientists investigate whether a “superworm” can help solve our styrofoam problem.

It’s no secret that plastic has become a huge challenge for our poor old planet. Concerned people are finding solutions where they can. Ploggers of India (and other countries) pick plastic off the ground when they go jogging. Plastic Free Hackney is a UK town that aims to do without. Artists turn plastic waste into sculptures.

In today’s story, we learn about scientists testing a “superworm” that might be able to break down a particular kind of plastic, styrofoam.

Pranshu Verma reports at the Washington Post, “A plump larva the length of a paper clip can survive on the material that makes Styrofoam. The organism, commonly called a ‘superworm,’ could transform the way waste managers dispose of one of the most common components in landfills, researchers said, potentially slowing a mounting garbage crisis that is exacerbating climate change.

“In a paper released [in June] in the journal of Microbial Genomics, scientists from the University of Queensland in Brisbane, Australia, showed that the larvae of a darkling beetle, called zophobas morio, can survive solely on polystyrene, commonly called Styrofoam.

“The findings come amid a flurry of research on ways bacteria and other organisms can consume plastic materials, like Styrofoam and drinking bottles.

“Now, the researchers will study the enzymes that allow the superworm to digest Styrofoam, as they look to find a way to transform the finding into a commercial product. Industrial adoption offers a tantalizing scenario for waste managers: A natural way to dispose and recycle the Styrofoam trash that accounts for as much as 30 percent of landfill space worldwide. …

“The material is dense and takes up a lot of space, making it expensive to store at waste management facilities, industry experts said. The cups, plates and other materials made from it are also often contaminated with food and drink, making it hard to recycle. Polystyrene fills landfills, where it can often take 500 years to break down and decompose, researchers have found. …

“In 2015, researchers from Stanford University revealed that mealworms could also survive on Styrofoam. The next year, Japanese scientists found bacteria that could eat plastic bottles. In April, researchers from the University of Texas found an enzyme which could digest polyethylene terephthalate, a plastic resin found in clothes, liquid and food containers. …

“[The Microbial Genomics study’s coauthor Christian Rinke] said he was excited by his research results but noted it will take time to develop into an industrial solution, estimating somewhere between five to 10 years.

“To conduct the study, his research team in Australia fed the superworms three separate diets. One group was given a ‘healthy’ solution of bran. The second was given polystyrene. The third was put on a starvation diet.

“Ninety percent of the larvae that ate bran became beetles, compared with roughly 66 percent from the group given polystyrene and 10 percent from those forced to starve. This indicated to researchers that superworms have enzymes in their gut that can effectively digest Styrofoam.

“Next, the scientists will study those enzymes to see how well they can digest polystyrene on a large scale — modifying them if necessary to become more effective. ‘We want to not have gigantic superworm farms,’ he said. ‘Rather, we want to focus on the enzyme.’

“If the research proves successful, Rinke said waste managers could collect and grind Styrofoam materials and put them into a liquid solution made with the superworm enzyme. The solution would ideally dispose of the Styrofoam or digest it in a way that allows new plastic products to be created, thereby reducing the need for new plastic materials, Rinke said.

“ ‘If you can go all the way to the end,’ he said, ‘the idea is to use the system and come up with a biological solution to recycle plastic.’

“Despite the findings from Rinke and others, there are reasons that none have successfully translated into industry applications over the past decade, researchers said. Andrew Ellington, a professor of molecular biosciences at the University of Texas at Austin, said it has been difficult to find a plastic-digesting organism or enzyme that can operate in industrial conditions, which often process trash in very hot environments or through the use of organic solvents. … He suggested an alternative solution.

“ ‘I believe that we will be able to offer up, in the not-so-distant future, worm-based composting kits so that individuals can do this themselves,’ he said.

“Jeremy O’Brien, the director of applied research at the Solid Waste Association of North America, said there are other business challenges in putting this type of solution into use. As envisioned, the solution would require waste managers to collect Styrofoam separately from other trash, he said, which makes it cost-prohibitive.

“O’Brien also said it remains unclear what kind of organic waste the enzyme process would generate, and he worries it could harm the microorganisms landfills already use to process trash and reduce odors. He added that a more desirable and cost-effective solution would be to take Styrofoam in landfills and condense them enough so that they can be turned into new plastics.”

More at the Post, here. What do you think of this? Is breaking plastic down to enzymes enough to keep us safe?

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