Inability of Pythium Aphanidermatum and Phytophthora palmivora to Incorporate Acetate into Digitonin-Precipitable Sterols

Abstract

In-corporation of acetate-2-Cl4 into lipids of Pythium aphanidermatum. Phytophthora palmivora. Achlya flagellata. and Rhizopus stolonifer was studied. The first 2 fungi were unable to incorporate acetate into compounds precipitable with digitonin whether or not cholesterol was present in the medium; nor was there a digitonin precipitate when the nonsaponifiable lipid fraction from cultures grown on sterol-free medium was treated with digitonin. Cholesterol in the culture medium stimulated growth of the pythiaceous fungi but not of A. flagellata or R. stolonifer.