The Lipid Composition of Bacillus Cereus as Influenced by the Presence of Alcohols in the Culture Medium

Cells of Bacillus cereus grown in an alcohol-free medium (control cells) had a lipid content of 2.6 ± 0.4%, on a dry weight basis. About half of the lipids consisted of phosphatides, including phosphatidyl ethanolamine (40%), phosphatidyl glycerol (28%), lecithin (6%), lyso compounds (10%), and three acidic phosphatides of unknown structure. The fatty acids of the total lipids were predominantly saturated, the major components being branched-chain C13, C15, and C17acids. The neutral lipids consisted mostly of diglycerides, with a small amount of triglycerides. Five to ten per cent of the lipids was obtained as unsaponifiable material, consisting chiefly of long-chain (n-C16and n-C18) alcohols, and having traces of long-chain aldehydes (derived from plasmalogens).Cells grown in the presence of alcohols usually had a higher phosphatide content, a correspondingly lower non-phosphatide content, and a higher non-saponifiable content than control cells. Total lipid content or relative proportions of the phosphatide components in alcohol-grown cells did not differ significantly from those of control cells.