Branched alkanes and other apolar compounds produced by the cyanobacteriumMicrocoleus vaginatus from the Negev Desert

Gas chromatography-mass spectrometry on serially coupled capillary columns with different polarity of stationary phases showed that the soil cyanobact erium Microcoleus vaginatus from the Negev desert produces an unusual mixtu re of 4 normal and more than 60 branched alkanes, as well as a number of fa tty acids, cyclic and unsaturated hydrocarbons, aldehydes, alcohols, and ke tones. The dominant compounds were heptadecane (12%), 7-methylheptadecane ( 7.8%), hexadecanoic acid (6.5%), (Z)-9-hexadecenoic acid (5.6%), 4-ethyl-2, 2,6,6-tetramethylheptane (2.8 %), (Z)-9-octadecenoic acid (2.8%), and 4-met hyl-5-propylnonane (2.7%).