Abstract
Experimental data on genetic molecular classification and identification of the yeast genus Zygowilliopsis are summarized. The genus is represented by at least five biological species and three varieties: Z. californica: var. californica, var. dimennae, and var. fukushimae. Biogeography, ecology and killer activity of Z. californica yeasts is considered. Heterogeneity of the taxonomic genus Barnettozyma Kurtzman et al. (2008) and the necessity for its revision are discussed.