Exploring the Tenebrio molitor gut microbiota response to LDPE and PET: putative genetic indicators and...

Insect gut microbiomes are recognized as potential reservoirs of enzymatic activities relevant to plastic metabolism. Here, we investigated the taxonomic and functional dynamics of the Tenebrio molitor gut microbiota under dietary exposure to low-density polyethylene (LDPE) and polyethylene terephthalate (PET) using 16S rRNA sequencing and shotgun metagenomics. Significant compositional shifts were detected at the ASV level, with plastic-fed cohorts showing enrichment of taxa implicated in xenobiotic metabolism. Predicted functional changes suggested altered abundance of pathways related to aromatic compound processing and redox homeostasis. Metagenomic assembly and functional annotation, performed through a reproducible open-source workflow, revealed several putative proteins with distant homology to enzymes such as phthalate dioxygenases, urethanases, and polyhydroxyalkanoate depolymerases. A metagenome-assembled genome (MAG) assigned to Enterococcus accounted for most recovered protein-coding sequences. Although gene-level comparisons did not show statistically significant differences, Gene Set Enrichment Analysis (GSEA) highlighted ABC transporter signatures and stress-response ATPases under plastic-exposed conditions. Overall, this exploratory study reveals microbial shifts and putative genetic indicators of metabolic potential within the T. molitor gut, providing a reproducible analytical framework for future investigations into the microbial role in plastic bioconversion.