[Biomass accumulation by polyploid forms of Candida guilliermondii yeasts].

Under the action of a mitotic poison (acenaphthene), the haploid culture of Candida guilliermondii assimilating n-alkanes yielded a polyploid form whose cells were four times larger, on the average, than in the haploid culture. When the pure culture was grown under stationary conditions in media with glucose, the economical coefficient, i. e.

[Direct selection of Aspergillus terricola variants having different toxicity on a culture of fibroblasts].

A direct method is proposed to select less toxic mutants of Aspergillus terricola on a culture of fibroblasts. The conidia are first irradiated with UV, and then are used to grow colonies on the glass surface of tubes or flasks containing medium 199. The cells of fibroblasts are added thereupon and the two cultures are being grown together for 24--48 hours.