Uneven Culturable Yeast Communities Harbored by Two Sympatric Stingless Bee Species: Scaptotrigona depilis and Tetragona clavipes

Insects are essential partners for yeasts, playing a key role in their dispersal to new environments. Stingless bees (Apidae: Corbiculata: Meliponini) are social corbiculate bees which lack a functional sting. They are important pollinators in tropical and subtropical regions, foraging for nectar, pollen, and resins, thereby enriching their nests with plant-associated microbes, including yeasts. Here we assessed the yeast diversity associated with stingless bees and their provisions, by thoroughly sampling guts, brood cells, pollen, and honey pots, across seven different Meliponini species: Frieseomelitta varia, Melipona quadrifasciata, Scaptotrigona depilis, Scaptotrigona postica, Tetragona clavipes, Tetragonisca angustula, and Trigona cilipes. Yeast diversity was analyzed for the most extensively sampled bees, S. depilis and T. clavipes. Among the 20 yeast and yeast-like species recovered, we found a core dominant yeast community, primarily composed of Starmerella and Wickerhamiella yeasts, which are notorious to be associated with flowers and floricolous insects. Although the communities are dominated by specific yeast taxa with similar metabolic profiles, it differs among stingless bee species that occur in the same geographic area, as observed for S. depilis and T. clavipes. We suggest that yeast communities associated with stingless bees and their provisions contain overrepresented taxa and are shaped by host foraging choices.