[Assimilation of n-alkanes with a varying length of the carbon chain by the yeast Candida guilliermondii]. / Assimiliatsiia n-alkanov razlichnoi dliny uglerodnoi tsepi drozhzhhami Candida guilliermondii.

Using radioactive tracers, the effect of n-alkanes with a varying length--C16-C25--of the carbon chain on the rate of yeast growth and the ratio of major chemicals in their biomass was studied. The change in the level of n-alkanes accumulated by the yeast during carbon starvation was determined. No differences in the rate of metabolization of 1-14C-octadecane, 1,2-3H-hexadecane, and 13-14C-pentacosane were found. During 3 hour incubation the cell losses of C25, C18 and C16 amounted to 35.0, 33.0 and 38.1 microgram alkane/mg yeast, respectively. The intensity of yeast growth in the accumulative culture on dispersed n-alkanes with different molecular weights was similar. The specific formation of CO2 during the lag-phase by the yeast cultivated C18 was larger than on C23 or C25. The lipid content in the yeast grown on C18 was 3 times greater than in those grown on C22. The difference was made by an increased content of triglycerides and waxes.

[Studies of the primary distribution kinetics of n-alkane oxidation products according to morphological components of the yeast cell]. / Issledovanie kinetiki pervichnogo raspredeleniia produktov okisleniia n-alkana po morfologicheskim komponentam drozhzhevoi kletki

Incorporation of 14C into various classes of lipids localized in the cell walls, large membranes, mitochondria and microsomes of yeast cells was studied during their incubation with 1-14C-octadecane. Cell structures were found to differ considerably by the kinetics and level of accumulation of 14C-components of the lipid fraction. Waxes and triglycerides prevail during primary accumulation of 14C-lipids in the large membranes and cell walls. Synthesis of these compounds is presumed to play an important role in the course of primary transformation of n-octadecane.

[Primary distribution of n-alkane through the structures of yeast cells]. / Pervichnoe raspredelenie n-alkana po strukturam drozhzhevykh kletok

When n-alkane enters the cells as a result of molecular sorption and diffusion, it is distributed within all membrane structures of the cell (microsomes, mitochondria, membranes, vacuoles, cytoplasmic membranes, and cell walls). Sorption of n-alkane by all these structures in vivo comes at equilibrium after incubation of the cells with n-alkane during 3-4 min. Accumulation of the hydrocarbon in the morphological fractions of the cell depends on its concentration in the incubation medium. Isotherms of the sorption are convex curves. Sorption power, maximum sorption capacity, affinity and strength of the bonds with the hydrocarbon differ among the membrane structures of the cell. The maximum capacity of sorption of n-alkane by the structures does not correlate with the content of lipids and phospholipids in the structures. Sorption of n-alkanes is presumed to depend on the structural organization of lipids in the morphological fractions.

[Isolation and characteristics of the cellular structures of Candida tropicalis]. / Vydelenie i kharakteristika kletochnykh struktur Candida tropicalis

Using the method of radioactive indicators, the specific content of proteins, lipids, total phosphorus, and lipid phosphorus was estimated in the morphological cell fractions of Candida tropicalis after growth in a liquid mineral medium containing n-octadecane as a source of carbon. The morphological cell fractions were produced by means of differential centrifuging. The following comparatively pure fractions were obtained simultaneously: soluble fraction, microsomes, mitochondria, large membranes, and cell walls.