Biodegradation of Polystyrene by Tenebrio molitor, Galleria mellonella, and Zophobas atratus Larvae and Comparison of Their Degradation Effects.

Shan Jiang,Zhanyong Wang,Tingting Su,Jingjing Zhao

doi:10.3390/polym13203539

Shan Jiang, Zhanyong Wang + Show 2 more

Open Access

https://doi.org/10.3390/polym13203539

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Abstract

Plastic waste pollution and its difficult degradation process have aroused widespread concern. Research has demonstrated that the larvae of Tenebrio molitor (yellow mealworm), Galleria mellonella (greater wax moth), and Zophobas atratus (superworm) possess a biodegradation ability for polystyrene (PS) within the gut microbiota of these organisms. In this study, the difference in PS degradation and the changes of the gut microbiota were compared before and after feeding PS. The results showed that superworm had the strongest PS consumption capacity and the highest survival rate during the 30 d experiment period. They all could degrade PS to different degrees. Superworm showed the highest ability to degrade PS into low-molecular-weight substances, while yellow mealworm depolymerized PS strongly by destroying the benzene ring. The changes of the intestinal microbiome caused by feeding PS showed that after ingesting PS, there was a decrease in community diversity in superworm and yellow mealworm, but an increase in greater wax moth. Meanwhile, Enterococcus and Enterobacteriaceae, found in all three species’ larvae upon 20 d of PS feeding, might play an important role in PS degradation. The results will provide more accurate PS degradation comparative data of the three species’ larvae and theoretical guidance for further research on the efficient PS biodegradations.

Highlights

IntroductionThe convenience of using plastics by humans has led to the release of a large amount of plastic waste into the environment
Accepted: 12 October 2021It is generally believed that petroleum-based plastics, including polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polypropylene (PP), etc., are widely used due to their light weight, high strength, waterproof capacity, corrosion resistance, and low cost [1].The convenience of using plastics by humans has led to the release of a large amount of plastic waste into the environment
The biodegradation of PS and the changes of the intestinal microbial diversity occurred in the insect guts, which may be closely related to these changed intestinal microorganisms

Summary

Introduction

The convenience of using plastics by humans has led to the release of a large amount of plastic waste into the environment. These waste plastics have stable chemical properties, making it extremely difficult to naturally degrade them in the environment [2,3]. They lead to the pollution of the soil, atmosphere, and water to different degrees. Some of the traditional methods of disposing of waste plastic include incineration, landfill, or chemical recycling, which cannot fundamentally solve the problem of environmental pollution. More and more insect larvae have been found to possess the ability to feed on, degrade, and mineralize plastics, such as Tenebrio molitor L., Galleria mellonella L., Zophobas atratus Fab., Tenebrio obscurus Fab., Plodia interpunctella Htibner, Tribolium castaneum Herbst, Lasioderma

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