Cellular fatty acid composition of cyanobacteria assigned to subsection II, order Pleurocapsales

The cellular fatty acid composition of five of the six genera of unicellular cyanobacteria in subsection II, Pleurocapsales (Dermocarpa, Xenococcus, Dermocarpella, Myxosarcina and the Pleurocapsa assemblage) contained high proportions of saturated straight-chain fatty acids (26-41% of the total) and unsaturated straight chains (40-67%). Isomers of 16:1 were the main monounsaturated acid component (11-59%). Polyunsaturated acids were present at trace levels (0-1% or less) in Xenococcus and Myxosarcina, at concentrations of less than 7% in Dermocarpa, Dermocarpella, Pleurocapsa and CCMP 1489, and at high concentrations (35% or more) in Chroococcidiopsis. Chroococcidiopsis was also different in terms of the percentage of 16:1 isomers (10-12%) compared to other genera (30-59%), and in terms of total 16-carbon and 18-carbon fatty acids. In general, the composition and heterogeneity of fatty acids in the order Pleurocapsales was similar to that reported for the unicellular cyanobacteria of subsection I, order Chroococcales.