Metagenomic Insights Into the Gut Bacteria of Greater Wax Moth <i>Galleria mellonella</i> Linnaeus (Pyralidae: Lepidoptera) Larvae Reared on Plastic‐Incorporated Diet

ABSTRACT Plastic accumulation is a major environmental concern, and understanding biological responses to plastic‐incorporated diets is essential for identifying their biodegradation potential. Larvae of the greater wax moth ( Galleria mellonella Linnaeus) can feed on polymers, although the microbiological mechanism behind this observation is not well understood. Larvae were cultured on an artificial diet with various polymers (high‐density polyethylene [HDPE], low‐density polyethylene [LDPE], polystyrene [PS], and polyvinyl chloride [PVC]), and their gut bacteria were profiled by 16S ribosomal RNA gene (V1–V9) sequencing on the Oxford Nanopore platform. Bioinformatics pipelines were used to analyze diversity, taxonomic composition, and predicted metabolic functions. Sequencing revealed that the bacterial community in the gut was dominated by the phylum Bacillota, with Mammaliicoccus sciuri accounting for more than 90% of the total reads across all diets. Despite this dominance, plastic‐incorporated diets promoted low‐abundance taxa, increasing richness while maintaining similar evenness compared to the control. Beta diversity revealed distinct clustering of plastic‐fed samples, indicating polymer‐specific microbial shifts. Functional predictions showed enrichment of pathways related to heterotrophic metabolism, hydrocarbon degradation, fatty acid oxidation, and stress response, particularly in the HDPE‐ and PVC‐fed groups. These results indicate that plastic‐incorporated diets drive compositional and functional restructuring of the gut microbiota, suggesting microbial adaptation toward hydrocarbon utilization that may underpin early‐stage plastic biodegradation. However, these findings are based on predictive functional analyses and should be considered as presumptive evidence of potential plastic biodegradation, requiring further experimental validation through physicochemical and enzymatic studies.