Plasmenylethanolamine: growth factor for cholesterol-reducing Eubacterium

A plasmalogen, plasmenylethanolamine, is required for in vitro growth of strains of Eubacterium which convert cholesterol to coprostanol. Plasmenyl-ethanolamine was isolated from calf brain by selective saponification of lipid fractions separated by thin-layer or column chromatography. Cholesterol-containing thioglycolate broth plus purified plasmenylethanolamine or its 2-lyso derivative supported growth of Eubacterium ATCC 21408 and a cholesterol-reducing Eubacterium isolated from baboon feces. Plasmenylethanolamine obtained from commercial sources also supported growth of these organisms, but none of a number of other pure lipids would support growth. Metabolism of the alkenyl ether group of plasmenylethanolamine occurred during growth.