LIPIDS OF MARINE BACTERIUM FLEXIBACTER-POLYMORPHUS

The total fatty acid composition of a marine bacterium representative of the genus Flexibacter was reported. F. polymorphus is unusual in containing a high proportion of the polyunsaturated acid C20:5.omega.3 while the level of branched fatty acids is low. The membrane flexibility necessary for its gliding motility is a function of the polyunsaturated fatty acid composition. Biosynthetic precursors to the C20:5 acid are present which are characteristic of an O-dependent pathway. The fatty acid composition of the structural lipids is influenced by changes in the culture medium. Na2S inhibits production of the C20:5 acid at levels much lower than that at which it is known to inhibit growth. The intracellular granules observable in F. polymorphus do not contain S, unlike Beggiatoa sp., but instead probably contain lipids.