Bacterial and fungal diversity in the gut of polystyrene-fed Alphitobius diaperinus (Insecta: Coleoptera)

The use of plastics burgeoned in the last decades to become an essential component of our society. An environment friendly method to dispose of plastic waste is not available yet, to the outcome that these accumulate in landfills or are scattered as microplastics. New researches reported that some coleopteran species are able to destroy plastics thanks to their chewing mouthparts and the metabolic activity of their gut microbiota. This study shows that the lesser mealworm Alphitobius diaperinus is capable of feeding on, and apparently degrading, polystyrene. The gut microbiota of polystyrene-fed larvae was characterized using an NGS metagenomic approach, targeting both bacteria and fungi. Several microbe taxa emerged as differentially abundant between treatment and control groups (Cronobacter, Kocuria and Pseudomonas as bacteria, Aspergillus, Hyphodermella, Trichoderma as fungi). Some of them have been found in association with plastic compounds and/or have been proposed to be capable of plastic degradation. This research supports the notion that, although synthetic molecules, unlike most natural compounds, do not generally enter the natural food chain to be degraded by the environmental microbiota, some microbial communities may be able to decompose plastics. We speculate that, once identified, such communities may open to the possibility of devising bioreactors for plastic degradation.