Yamadazyma oleae f.a. sp. nov. and Yamadazyma molendinolei f.a. sp. nov., two novel ascomycetous yeast species isolated from olive oil mills in Italy, and reassignment of 11 Candida species to the genus Yamadazyma

Three yeast strains were isolated from an olive paste sample (CBS 18661) and two samples of olive oil (CBS 18662 and CBS 18660) were collected in two different mills in Verona province, Italy. The sequence comparison of the D1/D2 domains of the LSU rRNA gene and the internal transcribed space (ITS) regions indicated that these strains belonged to the genus Yamadazyma. Phylogenetic analysis of concatenated sequences of the ITS regions and the D1/D2 domains indicated that they represented members of two distinct species. Strain CBS 18661 and CBS 18662 showed sequence divergence of 2.7–2.8% (13–15 nucleotide substitutions) in the D1/D2 domains from the holotype of Yamadazyma luoyangensis, Yamadazyma ovata, Yamadazyma siamensis and Candida kanchanaburiensis and 5.9–6.2% identities (36–38 nucleotide substitutions) in the ITS regions from Yamadazyma akitaenisis and Yamadazyma nakazawae. Strain CBS 18660 showed sequence divergence of 0.75–1.1% (4–6 nucleotide substitutions) from Y. ovata, Candida trypodendri and Candida insectorum and 3.2–4.1% (18–24 nucleotide substitutions) in the ITS regions from Yamadazyma dushanensis, Yamadazyma terventina, Yamadazyma mexicana and C. trypodendri. The strains CBS 18661T (PP391581-PP375117) and CBS 18662 (PP391582-PP375118) are named Yamadazyma oleae f.a. sp. nov., whereas CBS 18660T (PP149061-PP130150) is assigned as Yamadazyma molendinolei f.a. sp. nov. The MycoBank numbers are MB 854683 and MB 854684, respectively. In addition, 11 Candida species belonging to the Yamadazyma clade have been reassigned to the genus Yamadazyma with the proposal of the following new combinations: Yamadazyma aaseri comb. nov., Yamadazyma conglobata comb. nov., Yamadazyma dendronema comb. nov., Yamadazyma diddensiae comb. nov., Yamadazyma germanica comb. nov., Yamadazyma insectorum comb. nov., Yamadazyma kanchanaburiensis comb. nov., Yamadazyma naeodendra comb. nov., Yamadazyma pseudoaaseri comb. nov., Yamadazyma trypodendri comb. nov. and Yamadazyma vaughaniae comb. nov.