Fatty Acids of Extractable and Bound Lipids of Rhodomicrobium vannielii

Cells of Rhodomicrobium vannielii grown at 29 C in a lactate-containing medium were extracted at room temperature with organic solvents. The extractable fraction contained the bulk of the simple lipid (1.87% of cell dry weight) and complex lipids (phospholipids, 4.2%; sulfolipid, 0.01%), coenzyme Q (0.09%), and pigments (carotenoids 1.2%; bacteriochlorophyll, 1.9%). The cell residue contained the bound lipids (nonpolar fatty acid fraction, 1.86%; polar hydroxy fatty acids, 0.49%). The residue also contained poly-beta-hydroxybutyric acid (0.2%), which was extracted in boiling chloroform. In both the simple and complex lipids, vaccenic acid (11-octadecenoic acid) was the largest single component (approximately 90% in each fraction). The fatty acids of the bound lipid contained 35% vaccenic acid, even- and odd-numbered saturated and unsaturated straight-chain fatty acids, cyclopropane-, branched-, and alpha- and beta-hydroxy fatty acids. The extractable lipids contained only straight-chain saturated and unsaturated even-numbered fatty acids. Nearly 60% of hydroxy fatty acid fraction was alpha-hydroxydodecanoic acid (24%) and beta-hydroxydodecanoic acid (34.5%). Coenzyme Q was crystallized and identified as Q(9) on the basis of melting point and chromatographic properties. Q(10) had been previously reported.