Saccharomycopsis yichangensis sp. nov., a Novel Predacious Yeast Species Isolated From Soil.

Abstract

Two yeast strains belonging to the ascomycetous yeast genus Saccharomycopsis were isolated from soil collected from a forest in Wufeng Tujia Autonomous County, Yichang, Hubei province, China. Phylogenetic analyzes of the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit rRNA gene showed that they closely related to S. fermentans and S. babjevae but differed from S. fermentans by 17 (3.09%, 15 substitutions and two gaps) and 30 (4.85%, 22 substitutions and eight gaps) mismatches, and from S. babjevae by 13 (2.39%, eight substitutions and five gaps) and 21 (3.46%, 14 substitutions and seven gaps) mismatches in the D1/D2 domain and ITS region, respectively. A phylogenomic analysis based on 1260 single-copy orthologs confirmed the close relationship of the new Chinese strains with S. fermentans and S. babjevae. The whole genome average nucleotide identity (ANI) values of the new strains with the two species are 85.7% and 86.9%, respectively. The results suggest that the two strains represent a novel species, for which the name Saccharomycopsis yichangensis sp. nov. (holotype strain CGMCC 2.7390) is proposed. The Fungal Names number is FN 572295. The novel yeast is homothallic and produces asci containing four spheroidal ascospores with an equatorial or subequatorial ledge. This species can prey on cells of Jamesozyma jinghongensis, Meyerozyma carpophila and Saccharomyces cerevisiae through invasive infection pegs.