VOLATILE ORGANIC-CHEMICALS OF A SHORE-DWELLING CYANOBACTERIAL MAT COMMUNITY

The main components of a cyanobacterial mat community of a hypersaline lake shore consist of edaphic, mat-forming strains (ecophenes), and littoral strains of Oscillatoria animalis Agardh and O. subbrevis Schmidle, other microorganisms associated with these cyanobacteria, several species of Bembidion (Carabidae: Coleoptera), and two halophytic flowering plants: Puccinellia nuttalliana (salt meadow grass) and Salicornia europaea rubra (samphire). The volatile organic compounds of this community are a blend of those emitted by each of these components such as the C-17 alka(e)nes, geosmin, 2-methylisoborneol, beta-cyclocitral, beta-ionone, dimethyl sulfide, and dimethyl trisulfide of cyanobacteria and associated microorganisms; alcohols, esters, and aldehydes usually associated with flowering plants; and possibly some insect-derived esters, particularly isopropyl tetradecanoate. The dominant compounds were: C-11, C-13, C-15, and C-17 alka(e)nes, methyl esters Of C-16 and C18:2 acids, isopropyl tetradecanoate, heptanal, 3-octanone and 2-nonanone, the acyclic terpene linalool, and the alcohols 1-heptanol, 1-hexanol, 1-octanol, 3-hexen-1-ol, and 2-octen-1-ol. It is concluded that this community may be distinguished from related communities by its repertoire of volatile organic compounds.