[Fatty acid composition and phospholipid pattern in auxotrophs for unsaturated fatty acids (author's transl)]

The relationship between fatty acid composition and phospholipid pattern has been studied in Escherichia coli auxotrophs for unsaturated fatty acids. 1. The presence of a regulatory mechanism which enables the organism to maintain a given fluidity of the lipids has been corroborated using exogenous fatty acids which cause dramatic changes in fatty acid composition. 2. The fatty composition of phosphatidic acid is different from that of the other classes of phospholipids. 3. Changes in fatty acid composition are concomittant with the alteration of the phospholipid pattern. The ratio of phosphatidylglycerol to diphosphatidylglycerol is particularly sensitive to the physical characteristics of the exogenous unsaturated fatty acid. The relative increase in diphosphatidylglycerol is associated with membrane alterations.