Genomic Characterization of Aerobically Culturable Gut-Associated Bacteria and Yeasts Isolated from Pooled Larval Midguts of the Lesser Mealworm Alphitobius diaperinus (Coleoptera: Tenebrionidae)

Abstract

Simple Summary Advances in genome sequencing allow the identification of bacteria and yeasts with high taxonomic resolution, providing insights into microbial ecology, predicted metabolic potential, and functional roles beyond traditional morphology- or biochemistry-based methods. In this study, we investigated the culturable fraction of the gut microbiota derived from a single pooled sample of fifteen larvae of the lesser mealworm, Alphitobius diaperinus, a key pest in poultry production, under limited aerobic conditions. A total of twelve isolates were initially obtained (ten bacteria and two yeasts), but eight bacterial isolates were identical, so a single representative was selected. Using Illumina whole-genome sequencing, we identified three bacterial strains and two yeasts. Although this culturable fraction represents a minor proportion of the total gut community it offers a critical advantage over culture-independent approaches: these isolates can be maintained under laboratory conditions, enabling direct functional experiments, strain-level genomic resolution and biotechnological exploitation. No novel species were detected, yet our results reveal microorganisms with distinct functional profiles isolated in the larval gut. This work establishes a genome-resolved reference framework for the cultivable bacteria and yeasts isolates obtained from healthy A. diaperinus larvae in the present study and provides genomic resources for future ecological and functional investigations.