| Popis: |
The oleaginous yeast Apiotrichum curvatum was grown on various lipids as carbon sources. When commercial animal and vegetable oils were used as substrates, the yeast triglyceride had a fatty acid profile similar to that of the substrate oil, but the glyceride structures were altered. Saturated free fatty acids with less than 14 carbons could not be used as carbon sources by the yeast. An emulsion of palmitic acid was well utilized by the yeast, but it was extensively desaturated before being deposited in the yeast triglyceride. Stearic and arachidic acid emulsions gave very limited and no growth, respectively. Oleic acid supported very good yeast growth; eicosenoic acid supported limited growth; erucic acid gave very poor growth. The yeast grew on petroselinic acid and deposited it extensively in its triglyceride. When supplemented with 1000 ppm butylated hydroxyanisole, linoleic and linolenic acids showed excellent growth and lipid accumulation. The yeast deposited ricinoleic acid, eleostearic and vernolic acids in its triglyceride when the yeast was grown on triglycerides containing these fatty acids, but the yeast triglyceride contained less of these conjugated and oxygenated acids than were found in the substrate oils. When crambe oil was used as a carbon source for the yeast, fatty acids with 20 or more carbons were concentrated in the residual substrate oil while those with 16 and 18 carbons were almost completely utilized. When cholesterol was incorporated in the growth medium, the yeast incorporated very little of it into its depot fats. |
