Zygosaccharomyces seidelii sp. nov. a new yeast species from the Maldives, and a revisit of the single-strain species debate.

Zygosaccharomyces seidelii, a new species in the genus Zygosaccharomyces is described. The description of the species is based on a single strain that was isolated from flowers collected on the Maldives. On this occasion, the description of yeast species from single strains was revisited. Sequence analysis of the D1/D2 domain of the nuclear large subunit rRNA gene revealed that Z. seidelii is closely related to Z. gambellarensis. Both species differ by 2.6% (one indel of 7 bp and 9 substitutions) in the D1/D2 domain, 71 substitutions and 23 indels in the ITS1-5.8S-ITS2 (ITS) region and by several physiological tests. Two divergent copies of the ITS region were detected in Z. seidelii. Asexual and sexual reproduction as well as the physiological properties of Z. seidelii fit well in the genus Zygosaccharomyces. (Holotype strain: CBS 16021, Isotype strain: CLIB 3343; MycoBank no.: MB830900).