Influências e alterações no perfil metabólico de Alphitobius diaperinus (Coleoptera:Tenebrionidae) na sua utilização como biodegradador de poliestireno

Abstract

The world production of plastics has increased very quickly in the last 50 years, with emphasis on the Chinese production, responsible for ¼ of the world production. To date, no environmentally friendly method is available to dispose of plastic waste, which accumulates in landfills or is scattered as microplastics. In this context, biodegradation emerges as a sustainable alternative, as it consists in the mineralization of these materials through submission to microbial metabolism. Current research has reported that some coleopteran species are able to degrade plastics with the aid of their chewing mouthparts and the metabolic activity of their intestinal microbiota. This study shows that Alphitobius diaperinus is able to feed on and apparently degrade polystyrene. The metabolic profile of larvae fed with poultry feed, subjected to absolute fasting and fed with polystyrene were characterized through a metabolic approach where the steps of the analysis of the metabolic profile involved sample preparation, extraction of substances from the tissue of the living organism, derivatization of extracted substances, injection into the chromatograph, processing and identification of substances, statistical analysis and interpretation of results. Along with this, the larval length, dry weight and integrity of the digestive tract were included. A total of 50 metabolites were found and among them the metabolites of the polyalcohol, nitrogen and amino acid classes in A. diaperinus larvae submitted to fasting and in the Polystyrene (PS) diet had a significant increase in relation to larvae fed with ration for birds. Showing that even if they were able to chew/crush polystyrene, the metabolism of larvae fed with PS is very similar to that of larvae in fasting condition. Despite this, this research supports the notion that while synthetic molecules, unlike most natural compounds, do not generally enter the natural food chain to be degraded by environmental microbiota, some species of alternative plastic degraders may be able to decompose plastics. Due to the results found, A diaperinus, although it does not decompose all the PS, can be used as its initial degrader. From this it appears that the present study will contribute in the long term to provide adequate, sustainable and profitable management of these post-consumer materials.