Evaluating Bioremediation Potential for Plastic Pollution with Wax Worms, Galleria mellonella

Abstract

Recently researchers have been seeking methods to address plastic pollution problems. These range from oceanic harvesters, to washing machine bags which limit fiber emissions, to bioremediators. In 2015, researchers determined that 100 Galleria mellonella (Wax Worms) were capable of consuming 92 mg of polyethylene in a 12 hour period. In order to assess Wax Worms’s potential as bioremediators, we ran pilot trials using 5 worms under low and high light conditions and exposed them to different forms of plastic such as; PVC (tubing), PET (water bottle), polypropylene (bottle cap), ethylene/vinyl acetate (inner liner bottle cap), and hydroxypropyl methyl cellulose (overhead projector sheet), as well as no plastic (control worms). Additional trials (including additional plastic types) are in progress with adjustments in conditions and worm abundance based on pilot study findings. FT-IR (Fourier Transform Infrared Spectroscopy) was used to verify both plastic and fecal polymer composition. Both worms and plastics were photodocumented before and during the experiment to assess signs of foraging (e.g., channeling, chewing) morphological changes in plastics. Fecal material was found to be nylon and azlon (casein) suggesting worms are processing plastic. Consumption of plastic varied across polymers, specifically more polypropylene, PET, and hydroxypropyl methyl cellulose was consumed compared to other types. Channeling was noted on several plastic pieces. Our lab experiment will serve as a baseline for future testing of the bioremediation potential of Wax Worms at addressing small-scale plastic pollution.