Taxonomic Identification of Two Novel Genera and Four Novel Species of Lipolytic Floral-Associated Yeasts

Floral yeasts are generally recognized to exhibit high metabolic activities. We isolated 437 yeast strains from 45 flower samples collected from different plants in the Beijing Olympic Forest Park, a unique urban ecosystem harboring diverse plants, which facilitated a thorough survey of floral yeast diversity. Based on a sequence analysis of the D1/D2 domain of the large subunit ribosomal RNA gene (LSU rRNA) and the internal transcribed spacer region (ITS), these strains were assigned to 69 species, with Filobasidium magnum, Starmerella bombicola, Teunia globosa, Aureobasidium pini, and Kwoniella ovata being the dominant taxa. Ten representative strains were characterized comprehensively and identified as two novel genera and four novel species. Integrating the molecular data, genome information, and phenotypic/physiological traits, the ten novel yeast strains were described as six novel yeast taxa, including two novel species of two novel genera, Fanglaniella lipolytica gen. nov. sp. nov., Polychromogenomyces tardus gen. nov. sp. nov., and four novel species as Pseudotremella jasmini sp. nov., Teunia pruni sp. nov., Kurtzmanomyces yulaniae sp. nov., and Trigonosporomyces otomorphus sp. nov. Furthermore, qualitative profiling of the lipolytic activity across all six novel taxa was conducted using Tween 20 and Tween 80 plate culture assays, and the lipolytic functional genes were subsequently predicted. Our findings highlighted the high diversity of flower-inhabitant yeast strains and the potential lipolytic activity of floral yeasts.