Two new species of the methanol assimilating ascosporic yeast genus Komagataella are described. Komagataella populi sp. nov. (NRRL YB-455, CBS 12362, type strain, MycoBank accession number = 564110) was isolated from an exudate on a cottonwood tree (Populus deltoides), Peoria, Illinois, USA, and Komagataella ulmi sp. nov. (NRRL YB-407, CBS 12361, type strain, MycoBank accession number = 564111) was isolated from the exudate on an elm tree (Ulmus americana), also growing in Peoria, Illinois. The species were resolved from divergence in gene sequences for domains D1/D2 LSU rRNA, ITS1-5.8S-ITS2, mitochondrial small subunit rRNA, RNA polymerase subunit 1 and translation elongation factor-1α. Species of Komagataella assimilate few carbon compounds and are unlikely to be resolved from differences in standard growth and fermentation tests. For this reason, separation of species is dependent on gene sequence analysis.
Keywords: Komagataella; Methanol yeasts; New ascosporic yeasts.