Sensitive cells of Rhodotorula araucariae treated with killer toxin pr
oduced by two strains of the red basidiomycetous yeast Sporidiobolus p
araroseus were stained with methylene blue and released UV absorbing m
aterial into the growth medium. They also behaved as permeabilized cel
ls in a high-frequency field. All these phenomena indicate permeabiliz
ation of the sensitive cells.