Lipid metabolism of rumen ciliates and bacteria. I. Uptake of fatty acids by Isotricha prostoma and Entodinium simplex.

Washed suspensions of the ruminal ciliates, Isotricha prostoma and Entodinium simplex, concentrated C(14)-labeled oleic, palmitic, stearic, and linoleic acids within the cells during short incubation periods. Radioautographs demonstrated that oleic acid-1-C(14) was hydrogenated to stearic acid by I. prostoma, and Warburg manometric data showed that the sodium salts of oleic, valeric, caproic, and acetic acids, and methyl myristate, methyl laurate, and the triglyceride tributyrin stimulated fermentation of I. prostoma. The total lipid and free fatty acid contents of I. prostoma were determined.