oa Cyanobacterial Aromatic Carotenoids

Contrary to common perceptions, cyanobacteria can be the source of aromatic carotenoids preserved in sediments. Their distribution patterns differ, somewhat, from those produced by the phototrophic sulfur bacteria and are distinguished by the presence of C38 and C39 compounds which are diagenetic products of mono- and dicarboxylic acid precursors. Cyanobacterial aromatic carotenoids are most in evidence in samples from lacustrine environments and their existence likely explains some of the carbon isotopic variability of carotenoid assemblages previously thought to be derived from Chlorobi.