Phaffia rhodozyma is polyploid

Abstract

The ploidy of the red yeast Phaffia rhodozyma was evaluated using flow cytometric analyses of propidium iodide-stained cells and mutagenic inactivation kinetics. Our findings suggest that Phaffia rhodozyma is not haploid. Auxotrophic strains were generated at a high frequency following treatment of mutagenized cells with a combination of benomyl and ethyl acetate. Studies of an auxotrophic mutant using flow cytometry and UV inactivation indicated possible chromosome loss to an aneuploid state.