AUTHOR=de Paula Gabriela Toninato , Melo Weilan Gomes da Paixão , Castro Ivan de , Menezes Cristiano , Paludo Camila Raquel , Rosa Carlos Augusto , Pupo Mônica Tallarico 

TITLE=Further evidences of an emerging stingless bee-yeast symbiosis

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1221724

DOI=10.3389/fmicb.2023.1221724

ISSN=1664-302X

ABSTRACT=<p>Symbiotic interactions between microorganisms and social insects have been described as crucial for the maintenance of these multitrophic systems, as observed for the stingless bee <italic>Scaptotrigona depilis</italic> and the yeast <italic>Zygosaccharomyces</italic> sp. SDBC30G1. The larvae of <italic>S. depilis</italic> ingest fungal filaments of <italic>Zygosaccharomyces</italic> sp. SDBC30G1 to obtain ergosterol, which is the precursor for the biosynthesis of ecdysteroids that modulate insect metamorphosis. In this work, we find a similar insect-microbe interaction in other species of stingless bees. We analyzed brood cell samples from 19 species of stingless bees collected in Brazil. The osmophilic yeast <italic>Zygosaccharomyces</italic> spp. was isolated from eight bee species, namely <italic>Scaptotrigona bipunctata</italic>, <italic>S. postica</italic>, <italic>S. tubiba</italic>, <italic>Tetragona clavipes</italic>, <italic>Melipona quadrifasciata</italic>, <italic>M. fasciculata</italic>, <italic>M. bicolor</italic>, and <italic>Partamona helleri</italic>. These yeasts form pseudohyphae and also accumulate ergosterol in lipid droplets, similar to the pattern observed for <italic>S. depilis</italic>. The phylogenetic analyses including various <italic>Zygosaccharomyces</italic> revealed that strains isolated from the brood cells formed a branch separated from the previously described <italic>Zygosaccharomyces</italic> species, suggesting that they are new species of this genus and reinforcing the symbiotic interaction with the host insects.</p>