Skip to main content
Sister Publication Links
  • Sustainable Plastics
  • Rubber News
Subscribe
  • Sign Up Free
  • Login
  • Subscribe
  • News
    • Processor News
    • Suppliers
    • More News
    • Digital Edition
    • End Markets
    • Special Reports
    • Newsletters
    • Resin pricing news
    • Videos
    • Injection Molding
    • Blow Molding
    • Film & Sheet
    • Pipe/Profile/Tubing
    • Rotomolding
    • Thermoforming
    • Recycling
    • Machinery
    • Materials
    • Molds/Tooling
    • Product news
    • Design
    • K Show
    • Mergers & Acquisitions
    • Sustainability
    • Public Policy
    • Material Insights Videos
    • Numbers that Matter
    • Automotive
    • Packaging
    • Medical
    • Consumer Products
    • Construction
    • Processor of the Year
    • Best Places to Work
    • Women Breaking the Mold
    • Rising Stars
    • Diversity
    • Most Interesting Social Media Accounts in Plastics
  • Opinion
    • The Plastics Blog
    • Kickstart
    • One Good Resin
    • Pellets and Politics
    • All Things Data
    • Viewpoint
    • From Pillar to Post
    • Perspective
    • Mailbag
    • Fake Plastic Trees
  • Shop Floor
    • Blending
    • Compounding
    • Drying
    • Injection Molding
    • Purging
    • Robotics
    • Size Reduction
    • Structural Foam
    • Tooling
    • Training
  • Events
    • K Show Livestream
    • Plastics News Events
    • Industry Events
    • Injection Molding & Design Expo
    • Livestreams/Webinars
    • Editorial Livestreams
    • Ask the Expert
    • Plastics News Events Library
    • Processor of the Year submissions
    • Plastics News Executive Forum
    • Injection Molding & Design Expo
    • Plastics News Caps & Closures
    • Women Breaking the Mold Networking Forum
    • Plastics in Automotive
    • PN Live: Mergers and Acquisitions
    • Polymer Points Live
    • Numbers that Matter Live
    • Plastics in Politics Live
    • Sustainable Plastics Live
    • Plastics Caps & Closures Library
    • Plastics in Healthcare Library
    • Women Breaking the Mold Networking Forum Library
  • Rankings & Data
    • Injection Molders
    • Blow Molders
    • Film Sheet
    • Thermoformers
    • Pipe Profile Tubing
    • Rotomolders
    • Mold/Toolmakers
    • LSR Processors
    • Recyclers
    • Compounders - List
    • Association - List
    • Plastic Lumber - List
    • All
  • Directory
  • Resin Prices
    • Commodity TPs
    • High Temp TPs
    • ETPs
    • Thermosets
    • Recycled Plastics
    • Historic Commodity Thermoplastics
    • Historic High Temp Thermoplastics
    • Historic Engineering Thermoplastics
    • Historic Thermosets
    • Historic Recycled Plastics
  • Custom
    • Sponsored Content
    • LS Mtron Sponsored Content
    • Conair Sponsored Content
    • KraussMaffei Sponsored Content
    • ENGEL Sponsored Content
    • White Papers
    • Classifieds
    • Place an Ad
    • Sign up for Early Classified
MENU
Breadcrumb
  1. Home
  2. News
October 01, 2015 02:00 AM

Hungry mealworms may be the future of EPS recycling

Catherine Kavanaugh
Staff Writer
  • Tweet
  • Share
  • Share
  • Email
  • More
    Reprints Print
    Yu Yang/Stanford University
    A Stanford University study shows that mealworms can digest expanded polystyrene and excrete a product that may be suitable for crop planting.

    Outlawed in some U.S. cities as unrecyclable waste and controversial almost everywhere, the plastic foam carryout food container could become a new part of the mealworm's diet — and solve a major garbage problem in the process.

    Larvae of the darkling beetle will not only feed on expanded polystyrene, but microorganisms in their guts biodegrade it internally. And then, they poop out a seemingly safe product that may be suitable as soil for crops. Talk about waste disposal.

    The promising trash-to-food chain is unfolding in a laboratory at Stanford University, where a research team is the first to provide detailed evidence of bacterial degradation of plastic in an animal's gut.

    “It's actually astonishing to see the worms eating their way through the polystyrene,” Craig Criddle, a Stanford professor of civil and environmental engineering, said in a telephone interview. “It is surprising.”

    Another surprise is that the PS doesn't seem to be toxic to the insects, which also are getting potatoes and food scraps for a nutritious balanced diet.

    “They're fine with a little bit of the good stuff on the side,” Criddle said.

    He is supervising the study at Stanford, which is being led by senior researcher Wei-Min Wu in collaboration with colleagues in China. The study is still in its early stages, but Wu described in an email the high hopes he has for its implications: “to find a way to remediate current plastic pollution.”

    Gut reactions

    Wu is building on research initiated at the Beihang University in China, where researchers observed waxworms, the larvae of Indian mealmoths, break down polyethylene in the form of plastic bags thanks to microorganisms in their guts. Wu said he decided to study EPS because it is commonly used for coffee cups and Americans throw away some 2.5 billion of those each year. The findings to date also are significant because EPS “has been considered basically non-biodegradable and it causes pollution problems in soil, rivers, lakes and oceans,” Wu said.

    In the Stanford study, 100 mealworms ate 34-39 milligrams of EPS — the equivalent weight of a small pill — each day. Microbes in the guts of the baby bugs broke down the plastic and converted some of it into carbon dioxide and some of it into biodegradable fragments, which were excreted like tiny rabbit droppings within 24 hours.

    So far, that excreted waste appears safe to use as soil, according to the researchers.

    “Our findings have opened a new door to solve the global plastic pollution problem,” Wu said in a Sept. 29 news release.

    But first, many other questions need to be answered about the microbes and their role in the processing of the plastic.

    “The insects do some of the work because they're chewing up the material,” Criddle said. “Then the microbes take it to an even smaller scale by breaking it down with enzymes and that effectively is recycling the material at a molecular scale. In the near term we'd like to find out what the enzymes are and understand the conditions under which they are operating.”

    When the microbes are grown outside the insect, they still break down the polystyrene but not at as high of a rate, Criddle said.

    “The rate of degradation seems to happen faster inside these worms,” he said. “Something is occurring inside the insect.”

    Eating away

    A lot of questions about how the mealworms process plastics and what that could mean for the polluted planet are eating away at the researchers.

    “If we learn more about new enzymes or new processes, how can we engineer them in way that helps get rid of the problem,” Criddle asked. “…There are many issues with [EPS] and these other plastics so we need to find solutions to these problems for many reasons. Landfills are filling up. There's ocean debris.”

    Scientists could be at the forefront of engineering more powerful enzymes to degrade plastic or guiding manufacturers to design polymers that don't accumulate in the environment or food chains.

    “This is early stage research,” Criddle said. “We don't know where it will go.”

    The researchers at Stanford and in China plan to study whether the microorganisms in mealworms and other insects could biodegrade other plastics, such as polypropylene, mircobeads and bioplastics. Wu said they also begin looking for a marine equivalent of the mealworm.

    The long-term ripple effect is exciting, Criddle said, but he doesn't want to raise hopes too high.

    “We're human beings. We have those hopes, too,” he said. “We don't want to raise expectations to a level where we can't meet them. We want to be realistic about what's possible this science. We just don't know; there's a lot we don't know right now.”

    RECOMMENDED FOR YOU
    ACI Plastics unwraps new Michigan film recycling plant
    Letter
    to the
    Editor

    Do you have an opinion about this story? Do you have some thoughts you'd like to share with our readers? Plastics News would love to hear from you. Email your letter to Editor at [email protected]

    Most Popular
    1
    PVC feedstock in train derailment prompts evacuation in Ohio
    2
    Material Insights: Resin prices rise, nonmarket correction for PE
    3
    Illinois AG sues 14 firms over PFAS contamination
    4
    Prices on the rise for PP, PVC
    5
    This is the year the reality of plastics EPR arrives in the US
    SIGN UP FOR OUR FREE NEWSLETTERS
    EMAIL ADDRESS

    Please enter a valid email address.

    Please enter your email address.

    Please verify captcha.

    Please select at least one newsletter to subscribe.

    Get our newsletters

    Staying current is easy with Plastics News delivered straight to your inbox, free of charge.

    Subscribe today

    Subscribe to Plastics News

    Subscribe now
    Connect with Us
    • LinkedIn
    • Facebook
    • Twitter
    • Instagram

    Plastics News covers the business of the global plastics industry. We report news, gather data and deliver timely information that provides our readers with a competitive advantage.

    Contact Us

    1155 Gratiot Avenue
    Detroit MI 48207-2997

    Customer Service:
    877-320-1723

    Resources
    • About
    • Staff
    • Editorial Calendar
    • Media Kit
    • Data Store
    • Digital Edition
    • Custom Content
    • People
    • Contact
    • Careers
    • Sitemap
    Related Crain Publications
    • Sustainable Plastics
    • Rubber News
    • Tire Business
    • Urethanes Technology
    Legal
    • Terms and Conditions
    • Privacy Policy
    • Privacy Request
    Copyright © 1996-2023. Crain Communications, Inc. All Rights Reserved.
    • News
      • Processor News
        • Injection Molding
        • Blow Molding
        • Film & Sheet
        • Pipe/Profile/Tubing
        • Rotomolding
        • Thermoforming
        • Recycling
      • Suppliers
        • Machinery
        • Materials
        • Molds/Tooling
        • Product news
        • Design
      • More News
        • K Show
        • Mergers & Acquisitions
        • Sustainability
        • Public Policy
        • Material Insights Videos
        • Numbers that Matter
      • Digital Edition
      • End Markets
        • Automotive
        • Packaging
        • Medical
        • Consumer Products
        • Construction
      • Special Reports
        • Processor of the Year
        • Best Places to Work
        • Women Breaking the Mold
        • Rising Stars
        • Diversity
        • Most Interesting Social Media Accounts in Plastics
      • Newsletters
      • Resin pricing news
      • Videos
    • Opinion
      • The Plastics Blog
      • Kickstart
      • One Good Resin
      • Pellets and Politics
      • All Things Data
      • Viewpoint
      • From Pillar to Post
      • Perspective
      • Mailbag
      • Fake Plastic Trees
    • Shop Floor
      • Blending
      • Compounding
      • Drying
      • Injection Molding
      • Purging
      • Robotics
      • Size Reduction
      • Structural Foam
      • Tooling
      • Training
    • Events
      • K Show Livestream
      • Plastics News Events
        • Plastics News Executive Forum
        • Injection Molding & Design Expo
        • Plastics News Caps & Closures
        • Women Breaking the Mold Networking Forum
        • Plastics in Automotive
      • Industry Events
      • Injection Molding & Design Expo
      • Livestreams/Webinars
        • PN Live: Mergers and Acquisitions
      • Editorial Livestreams
        • Polymer Points Live
        • Numbers that Matter Live
        • Plastics in Politics Live
        • Sustainable Plastics Live
      • Ask the Expert
      • Plastics News Events Library
        • Plastics Caps & Closures Library
        • Plastics in Healthcare Library
        • Women Breaking the Mold Networking Forum Library
      • Processor of the Year submissions
    • Rankings & Data
      • Injection Molders
      • Blow Molders
      • Film Sheet
      • Thermoformers
      • Pipe Profile Tubing
      • Rotomolders
      • Mold/Toolmakers
      • LSR Processors
      • Recyclers
      • Compounders - List
      • Association - List
      • Plastic Lumber - List
      • All
    • Directory
    • Resin Prices
      • Commodity TPs
        • Historic Commodity Thermoplastics
      • High Temp TPs
        • Historic High Temp Thermoplastics
      • ETPs
        • Historic Engineering Thermoplastics
      • Thermosets
        • Historic Thermosets
      • Recycled Plastics
        • Historic Recycled Plastics
    • Custom
      • Sponsored Content
      • LS Mtron Sponsored Content
      • Conair Sponsored Content
      • KraussMaffei Sponsored Content
      • ENGEL Sponsored Content
      • White Papers
      • Classifieds
        • Place an Ad
        • Sign up for Early Classified