Using the fusion of auxotrophic mutant protoplasts, improved Tńchosporon cutaneum hybrids have been obtained. They revealed better, from 15% to 50%, ability to hydrolizę cellulose, and higher, from 23% to 31%, production of biomass in the model medium. They enriched the medium containing a corn coffee extract and not preadapted for yeast cultivation with protein by about 15%.