Please use this identifier to cite or link to this item: http://dx.doi.org/10.14279/depositonce-6452
|Main Title:||Raman spectroscopic analysis of the calcium oxalate producing extremotolerant lichen Circinaria gyrosa|
Sánchez, Francisco Javier
Torre, R. de la
Vera, Jean Pierre Paul de
|Abstract:||In the context of astrobiological exposure and simulation experiments in the BIOMEX project, the lichen Circinaria gyrosa was investigated by Raman microspectroscopy. Owing to the symbiotic nature of lichens and their remarkable extremotolerance, C. gyrosa represents a valid model organism in recent and current astrobiological research. Biogenic compounds of C. gyrosa were studied that may serve as biomarkers in Raman assisted remote sensing missions, e.g. ExoMars. The surface as well as different internal layers of C. gyrosa have been characterized and data on the detectability and distribution of β-carotene, chitin and calcium oxalate monohydrate (whewellite) are presented in this study. Raman microspectroscopy was applied on natural samples and thin sections. Although calcium oxalates can also be formed by rare geological processes it may serve as a suitable biomarker for astrobiological investigations. In the model organism C. gyrosa, it forms extracellular crystalline deposits embedded in the intra-medullary space and its function is assumed to balance water uptake and gas exchange during the rare, moist to wet environmental periods that are physiologically favourable. This is a factor that was repeatedly demonstrated to be essential for extremotolerant lichens and other organisms. Depending on the decomposition processes of whewellite under extraterrestrial environmental conditions, it may not only serve as a biomarker of recent life, but also of past and fossilized organisms.|
|DDC Class:||570 Biowissenschaften; Biologie|
|Sponsor/Funder:||BMWi, 50WB1153, Analysen zur Stabilität und Degradation biogener Substanzen sowie zum Resistenzpotential der Fleche Buellia frigida unter simulierten Marsbedingungen und nach Exposition im LEO-Weltraum|
|Journal Title:||International journal of astrobiology|
|Publisher:||Cambridge University Press|
|Notes:||Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.|
This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
|Appears in Collections:||FG Terahertztechnologie » Publications|
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