Fungal community structure in bees: influence of biome and host species

Abstract

Understanding the ecological relationship between fungi and insects is essential for elucidating interactions in biodiverse regions such as South American biomes. This study aimed to evaluate the influence of biome, host species, and microhabitat on the community structure of yeasts (using culture-dependent methods) and fungi (culture-independent methods) in bees and to identify the functional characteristics of isolated strains. Samples were collected from the body, hive, honey, and beebread of bees from the genera Trigona, Scaptotrigona, Tetragona, Apis, Meliponas, and Tetragonisca in the Pantanal, Amazon, and Cerrado biomes. We isolated 176 strains representing 46 yeast species, predominantly from the genera Starmerella (44.32%), Hanseniaspora (5.16%), and Wickerhamiella (4.38%). Starmerella etchellsii (32%) was the most abundant species, while Aureobasidium leucospermi (< 0.01%) was the least abundant. Only S. etchellsii and S. apicola (11%) were present in all bee species. The composition and abundance of yeasts were significantly influenced by biome and host species (PERMANOVA, p < 0.05). Alpha diversity varied significantly among microhabitats (Dunn’s p < 0.05), bee species, and biomes (Duncan p < 0.05). Culture-independent methods identified 234 Ascomycota ASVs, 18 Basidiomycota ASVs, and 1 Mucoromycete ASV across 90 genera and 108 species. Saccharomycetales accounted for approximately 72% of the fungal abundance, with S. apicola (14.64%) and S. meliponinorum (11.21%) being the most abundant. Additionally, barcoding identified 100 ASVs of plants associated with bees, grouped into 22 families and 24 species, predominantly Asteraceae, Anacardiacea, Elaeocarpaceae, and Solanaceae. The functional characteristics of the yeasts showed potential for industrial applications, varying according to the strain.