Mycocinogeny in the genus Bullera: taxonomic specificity of sensitivity to the mycocin produced by Bullera sinensis.

A strain of Bullera sinensis that secretes a fungicidal thermolabile and protease-sensitive toxin was found. Its killer phenotype was cureless. Ascomycetous, ustilaginaceous yeasts and the members of the Sporidiales are insensitive to the B. sinensis killer toxin. The mycocin acts against tremellaceous yeasts only, except for Cystofilobasidium, Fellomyces and Trichosporon spp. The genera Mrakia, Bullera, Cryptococcus and Udeniomyces are heterogeneous in sensitivity pattern. The different responses of some anamorphic species to this mycocin are often consistent with the origin of the strains and the differences in sexual, chemotaxonomic and physiological characteristics between them.