Characterization of surface n-alkanes and fatty acids of the epiphytic lichen Xanthoria parietina, its photobiont a green alga Trebouxia sp., and its mycobiont, from the Jerusalem hills

Surface alkanes and fatty acids from the thalli of the lichen Xanthoria parietina , its photobiont Trebouxia sp., and its mycobiont were analysed by GC-MS. The green alga Trebouxia sp. synthesized mainly unsaturated fatty acids such as (Z,Z,Z )-9,12,15-18 : 3 (Z,Z )-9,12-18 : 2 and (Z )-9-18 : 1, and light alkanes C-8 -C-15 (up to 83% of total n -alkanes). However, the mycobiont contained mainly saturated fatty acids such as hexadecanoic (16 : 0) and octadecanoic acid (18 : 0), and also very long-chain n -alkanes C-22 -C-34 . Dehydroabietic acid was found in both lichen and mycobiont. The occurrence of different amounts of n -alkanes and fatty acids in the photobionts and mycobionts of X. parietina was shown for the first time. Lichens collected from different locations in the Jerusalem hills contained n -alkanes ranging in concentration from 187 to 211 mg.(g dry wt)(-1) ; n -alkane concentrations in the photobiont and mycobiont were 17-24 and 215-262 mg.(g dry wt)(-1) , respectively.