Calibration and validation of an experimental setup to study by remote sensing cyanobacteria responses under exo-Earth simulated environments

Recently, through space and ground-based observations, more than 3800 new exoplanets[1] have been discovered, many of which are terrestrial-like planets and could be therefore habitable. Due to the great distances separating us from these planets, any study regarding their habitability must be made through remote sensing techniques or in laboratory, by means of environmental condition simulations. Thanks to the collaboration between INAF, CNR-IFN and the department of Biology of Padova, a Star Light Simulator (SLS) and an Atmosphere Simulator Chamber (ASC) have been built. Using these devices, we study oxygenic photosynthetic microorganisms under simulated environmental conditions of terrestrial-like exoplanets orbiting M-type stars, to understand if they could maintain their oxygenic photosynthetic activity and furthermore impact on primeval atmospheres lacking oxygen. Testing these conditions requires light, temperature, pressure and atmospheric composition conditions that can be extremely different from terrestrial ones and imposes us to seal the ASC and assess the physiological responses of the cultures only at the beginning and at the end of the experiments. To overcome this issue, here we present a novel experimental setup to follow by remote sensing the growth and photosynthetic activity of oxygenic photosynthetic microorganisms by means of reflectivity, spectroscopic and fluorescence measurements, respectively. [1]: https://exoplanets.nasa.gov/