Science Snippet: Breaking Down Biodegradability

Have you ever noticed plastic utensils or paper plates labeled as “biodegradable” and wondered what that meant? Materials are biodegradable when microorganisms such as bacteria can break them down into their building blocks. Biodegradable Plastics Plastic is everywhere: Milk jugs, grocery bags, and takeout containers are just a few examples. There are many types of plastic, but they’re all made up of long chains of repeating subunits called polymers. These polymers are designed to be durable and resistant to factors like heat, sunlight, and water, which makes them useful in a variety of situations. Together, the enzymes PETase and MHETase break down the plastic polyethylene terephthalate (PET) into its two subunits: ethylene glycol (EG) and terephthalic acid (TPA). These enzymes are produced by a species of bacteria first found growing on plastic bottles in a recycling facility.Credit: David S. Goodsell and the RCSB Protein Data Bank. Traditional plastics take hundreds of years to break down naturally and end up in landfills and waterways. There, they pose a danger to wildlife who unknowingly ingest them, potentially blocking or tearing parts of their digestive systems and causing other issues. And sometimes, traditional plastic debris breaks down into tiny particles called microplastics that humans and other organisms can inhale or ingest. We don’t know how microplastics affect human health yet, but scientists are working to design new types of plastic...
Source: Biomedical Beat Blog - National Institute of General Medical Sciences - Category: Research Authors: Tags: Chemistry, Biochemistry and Pharmacology STEM Education Bacteria Science Snippet Source Type: blogs