Positional distribution of fatty acids in phospholipids from Bacillus subtilis

Abstract

The distribution of fatty acids between the 1- and 2-positions of phosphatidyl-glycerol and phosphatidylethanolamine of Bacillus subtilis (ATCC 7059) has been determined using phospholipase A, thin-layer chromatography and gas-liquid chromatography. Fatty acids present in the organism are normal-C 14 and C 16, iso-C 14, -C 15, -C 16, and -C 17, and anteiso-C 15 and -C 17, in addition to some minor fatty acids. A greatly increased synthesis of normal-C 15 and -C 17, fatty acids and synthesis of anteiso-C 14, and C 16 can be achieved by the addition of propionate and 3-methylpentanoate, respectively, to the standard culture medium. The positional distribution of the fatty acids in the phospholipids is summarized by the following generalizations: 1. 1. In all cases the 1-position of the phospholipids is largely occupied by iso-C 17, and anteiso-C 17, fatty acids, whereas the 2-position is mostly occupied by anteiso-C 15 fatty acid. 2. 2. Both chain length and terminal carbon skeleton affect positioning of fatty acids, the former being more influential than the latter. The preference towards the 1-position is as follows : longer chain length > shorter chain length, and normal >iso > anteiso series.