Fatty acid composition of the tropical lichenTeloschistes flavicansand its cultivated symbionts

Abstract

Fatty acid components, in both the free and combined form of the intact tropical lichen Teloschistes flavicans, and its isolated photobiont and mycobiont, were analyzed by GC-MS of derived methyl esters. Its rDNA analysis confirmed that the isolated cultured symbionts belong to the genera Trebouxia and Teloschistes, respectively. The fatty acid composition of the lichen did not correspond to those found in the isolated symbionts, suggesting that the fatty acid metabolism is markedly influenced by the symbiosis. Differences in the fatty acid composition in the lichen were observed during the summer (27 degrees C), when the main fatty acids were saturated and in the winter (22 degrees C) when an increase of unsaturated fatty acids occurred. Similar differences of composition were also observed for the cultured mycobiont at different temperatures. The increase in the unsaturation level at low temperatures would maintain the membrane fluidity. Our results are the first on the fatty acids of a tropical lichen and suggest that it is sensitive to small temperature variations, which influences its saturated and unsaturated fatty acid composition.

Culture studies on the mycobiont isolated from Parmotrema reticulatum (Taylor) Choisy: metabolite production under different conditions

“…Similar results were also reported for the mycobionts of Parmotrema eciliatum and Flavoparmelia exornata cultured on MY10 (Bertoni et al 2000). The production of triacylglycerides with or without additional primary fatty acids has also been reported for other lichen mycobionts in culture under different conditions (Adler et al 2004;Molina et al 2003;Reis et al 2005). These results indicate that fatty acids and acylglycerides commonly accumulate when mycobionts are grown under conditions that cannot drive the metabolism to the synthesis of lichen phenolics.…”

“…However, they also frequently biosynthesise different polyketides than those of the natural lichen, or primary triacylglycerides and fatty acids (Ahmadjian 1993;Huneck and Yoshimura 1996;Adler et al 2004;Molina et al 2003;Reis et al 2005). The obtained results are often difficult to interpret and factors favoring the production of lichen substances in culture have not been specified for several decades (Stocker-Wörgötter 2008).…”

Bioproduction of Depsidones for Pharmaceutical Purposes

“…Aposymbiotically grown mycobionts can also produce these secondary metabolites in culture. However, they also frequently biosynthesize different polyketides than those of the natural lichen, or primary triacylglycerides and fatty acids (Adler et al 2004;Molina et al 2003;Reis et al 2005). The obtained results are often difficult to interpret and factors favoring the production of lichen substances in culture have not been specified for several decades (Stocker-Wörgötter 2008).…”

Short-term monitoring of aridland lichen cover and biomass using photography and fatty acids

“…Gugger et al, 2002) or to determine biochemical changes in response to environmental cues (Bychek and Bychek, 1996;Reis et al, 2005), and to compare fatty acid composition of bionts in isolation and engaged in symbiosis (Reis et al, 2005). Though the technique is frequently used to characterize soil microbial communities at a coarse taxonomic scale (DeForest et al, 2004;Zak et al, 1996), it has not been applied as a biomass indicator or as a community profile for lichens or other BSC organisms.…”