Biodegradation and Mineralization of Polystyrene by Plastic-Eating Mealworms: Part 1. Chemical and Physical Characterization and Isotopic Tests

Environ Sci Technol. 2015 Oct 20;49(20):12080-6. doi: 10.1021/acs.est.5b02661. Epub 2015 Oct 1.


Polystyrene (PS) is generally considered to be durable and resistant to biodegradation. Mealworms (the larvae of Tenebrio molitor Linnaeus) from different sources chew and eat Styrofoam, a common PS product. The Styrofoam was efficiently degraded in the larval gut within a retention time of less than 24 h. Fed with Styrofoam as the sole diet, the larvae lived as well as those fed with a normal diet (bran) over a period of 1 month. The analysis of fecula egested from Styrofoam-feeding larvae, using gel permeation chromatography (GPC), solid-state (13)C cross-polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR) spectroscopy, and thermogravimetric Fourier transform infrared (TG-FTIR) spectroscopy, substantiated that cleavage/depolymerization of long-chain PS molecules and the formation of depolymerized metabolites occurred in the larval gut. Within a 16 day test period, 47.7% of the ingested Styrofoam carbon was converted into CO2 and the residue (ca. 49.2%) was egested as fecula with a limited fraction incorporated into biomass (ca. 0.5%). Tests with α (13)C- or β (13)C-labeled PS confirmed that the (13)C-labeled PS was mineralized to (13)CO2 and incorporated into lipids. The discovery of the rapid biodegradation of PS in the larval gut reveals a new fate for plastic waste in the environment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biodegradation, Environmental*
  • Carbon / metabolism
  • Carbon Dioxide / metabolism
  • Carbon Isotopes / analysis
  • Carbon Isotopes / metabolism
  • Chromatography, Gel
  • Eating
  • Larva / metabolism
  • Lipids / chemistry
  • Magnetic Resonance Spectroscopy / methods
  • Plastics / metabolism
  • Polystyrenes / metabolism*
  • Spectroscopy, Fourier Transform Infrared / methods
  • Tenebrio / metabolism
  • Tenebrio / physiology*
  • Thermogravimetry


  • Carbon Isotopes
  • Lipids
  • Plastics
  • Polystyrenes
  • Carbon Dioxide
  • Carbon
  • styrofoam