Lipid requirements for axenic cultivation of Entamoeba histolytica.

Fatty acids, cholesterol and glucose present in axenic medium are utilized by growing Entamoeba histolytica but the amoeba is unable to synthesize cholesterol from [U —14 C — ] glucose although the label is incorporated into the fatty acids and non-saponifiable fractions of the organism. Exogenously-added sonicated dispersions of cholesterol, β-sitosterol, lanosterol, lecithin and lauric, palmitic, linoleic and stearic acids are ingested by the amoebae with subsequent loss in amoeboid movement. After a few hours the movement is regained. Cholesterol, lecithin and the fatty acids stimulate amoebic multiplication but are unable to replace serum in the medium either singly or in combination.