We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Biodegradation of aged polyethylene (PE) and polystyrene (PS) microplastics by yellow mealworms (Tenebrio molitor larvae)
Summary
Yellow mealworm larvae were able to consume and biodegrade both fresh and aged polyethylene film and polystyrene foam over a 35-day period. While aged plastics slightly slowed larval growth, the worms still broke down the plastic with help from their gut bacteria, confirmed by chemical analysis showing structural changes in the consumed plastic. This biological approach to plastic degradation could help reduce the amount of plastic waste that eventually breaks down into microplastics in the environment.
Globally, over 287 million tons of plastic are disposed in landfills, rivers, and oceans or are burned every year. The results are devastating to our ecosystems, wildlife and human health. One promising remedy is the yellow mealworm (Tenebrio molitor larvae), which has proved capable of degrading microplastics (MPs). This paper presents a new investigation into the biodegradation of aged polyethylene (PE) film and polystyrene (PS) foam by the Tenebrio molitor larvae. After a 35 - day feeding period, both pristine and aged MPs can be consumed by larvae. Even with some inhibitions in larvae growth due to the limited nutrient supply of aged MPs, when compared with pristine MPs, the aged MPs were depolymerized more efficiently in gut microbiota based on gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) analysis. With the change in surface chemical properties, the metabolic intermediates of aged MPs contained more oxygen-containing functional groups and shortened long-chain alkane, which was confirmed by gas chromatography and mass spectrometry (GC-MS). High-throughput sequencing revealed that the richness and diversity of gut microbes were restricted in the MPs-fed group. Although MPs had a negative effect on the relative abundance of the two dominant bacteria Enterococcaceae and Lactobacillaceae, the aged MPs may promote the relative abundance of Enterobacteriaceae and Streptococcaceae. Redundancy analysis (RDA) further verified that the aged MPs are effectively biodegraded by yellow mealworm. This work provides new insights into insect-mediated mechanisms of aged MP degradation and promising strategies for MP sustainable and efficient solutions.