Ogataea (Hansenula) polymorpha and related yeasts were studied to clarify their taxonomy and phylogenetic relationships. The molecular analyses based on ribosomal DNA sequences revealed that (1) ATCC 14755, type strain of Pichia angusta, is phylogenetically distinguished from the majority of O. polymorpha strains including ATCC 34438(T) (=NRRL Y-5445(T)=CBS 4732(T)), type of the species; (2) Ogataea thermophila is conspecific to O. polymorpha; and (3) two of the strains, ATCC 26012 and ATCC 58401, are a novel Candida species closely related to O. polymorpha. The conclusions were also supported by physiological characteristics and other taxonomic features of these strains. Therefore, we propose here two novel species, Ogataea angusta comb. nov. (ATCC 14755(T)=CBS 7073(T)=NRRL Y-2214(T)) and Candida parapolymorpha sp. nov. (ATCC 26012(T)=NRRL Y-7560(T)), and conclude that O. thermophila is a synonym of O. polymorpha.
https://www.ncbi.nlm.nih.gov/pubmed/20491937