FIG. 6.

Mass spectra of the methyl esters of the unlabeled (a) and deuterated (b) 2-Me-15:0 fatty acids recovered from cultures of strain AK-01 grown on unlabeled and perdeuterated pentadecane, respectively. Chemical structures of the fatty acids represented by the mass spectra are shown as insets. Interpretation of the mass spectra shows that there are three deuterium atoms, located on C-2 and the 2-methyl group of the deuterated 2-Me-15:0 fatty acid. The locations of all three deuterium atoms on the 2-methyl group as shown in Fig. 6b represent one possible arrangement.