Microbial community formation during dietary exposure to Fe3O4-urease nanoconjugates in silkworm (Bombyx mori): Principal fungi groups facilitate functional flux

The gut microbiota of the silkworm ( Bombyx mori ) is essential for metabolic processes, including digestion and immunity. Nonetheless, the role of specific gut fungi in optimizing nutrient recycling influenced by infiltrated biomaterials remains inadequately elucidated. This study investigates the potential mechanisms through which gut fungi affect the dynamics of nutrient absorption in silkworms. For this purpose, 5th instar silkworms were exposed to Fe 3 O 4 -urease nanoconjugates for 168 h following the utilization of high-throughput microbiome sequencing to identify shifts in principal fungal groups. The conditional fungi groups Mucoromycota and Basidiomycota significantly increased from 10.28 % to 47.16 % and 0.53 % to 2.63 % respectively ( p  < 0.05), while Ascomycota decreased from 86.57 % to 52.29 %, having no negative impact on the growth and sustainability of the host insect. Functional analysis using FunGuild showed enriched trophic nodes including pathotrophs, saprotrophs and symbiotrophs while functions of DEGs demonstrated an increased metabolic capacity associated with iron and heme binding, and lipase activity. This reveals significant restructuring of the gut fungi microbiota with specific fungal taxa exhibiting enhanced abundance and diversity correlated with the presence of Fe 3 O 4 -urease nanoconjugates, serving as a potential for engineered nanomaterials to promote the sustainability and development of sericulture.