Description of project

 

The term extremophile describes an organism that exists under extreme physical or geochemical conditions, which usually do nor permit survival. In alpine regions such habitats are found on exposed rocky surfaces at high altitude, where several stress factors like increased UV-VIS radiation, vast temperature differences or a limited water and nutrient supply create a hostile environment. Yet, a few specialized organisms like green algae and cyanobacteria are able to survive. 

Tintenstrich 1 Tintenstrich 2
 Epilithic "Tintenstrich" cyanobacteria (Ötztal, Tirol)
 Epilithic Gloeocapsa sp. (field sample)

Despite these highly relevant ecological aspects little is known about the respective organisms. Most of them were identified taxonomically, but data about their secondary metabolites, their bioactivity or defence mechanisms in response to external stress is missing. Our project will overcome this lack of information by, for the first time, systematically studying changes in the metabolic patterns of alpine high altitude green algae and cyanobacteria exposed to elevated UVA and UVB radiation. Special focus will be put not only on the identification of respective compounds, but also on the fact whether these metabolites show bioactivity (anti-inflammatory, skin protection) as well (see workflow). Initially, from a selection of different green algae and cyanobacteria the pharmacologically most active ones will be selected after exposure of the specimens using the ORAC assay. They will be cultivated in larger scale, so that suitable analytical procedures for monitoring UV-stress induced compounds can be developed and bioactive constituents identified by chromatographic and spectroscopic methods. With references at hand further in-depth investigations will follow, targeting questions like when these protective agents are formed (sun simulation experiments) and how their bioactivity can be explained mechanistically (pharmacological studies using e.g. keratinocyte viability, ROS).

Our study joins aspects of ecology with phytochemistry, analytical sciences and pharmacology in a unique way. By investigating metabolites of organisms that hardly have been screened their relation can be studied on a chemosystematic level, their mechanisms of UV-protection investigated, and novel natural products with promising bioactivities explored. This will create a stable foundation for further research on alpine extremophil microorganisms, a group that largely has been overlooked by science till date.