New Publication - Cyanobacteria under simulated Red Dwarf star light: assessing exoplanet habitability.
Pubblicato il: 12.02.2021 12:00
Italian research group experimentally demonstrate that oxygenic photosynthesis is possible under simulated Red Dwarf light spectra (M7 type).
The study published in the journal “Life” (https://doi.org/10.3390/life11010010) has demonstrated for the first time that cyanobacteria are able to survive, grow and efficiently photosynthesize when exposed to the simulated spectrum of a Red Dwarf star. These types of stars are the most common in our Galaxy and a number of Earth-like planets have been discovered orbiting them. In the last years, scientists argued about the possibility to have oxygenic photosynthesis at work on these kinds of planets and thus to have the base for life development therin. The Red Dwarf stars are in fact quite different from our Sun: they can be up to 10 times less luminous and have a different emission spectrum, with major components in the Far-Red and Infrared lights (FR-IR) and only a fraction of the emission in the visible part of the light (VIS). The emission spectrum of the star is a fundamental constraint for performing oxygenic photosynthesis, as photosynthetic organisms mostly use VIS light to grow, with only few exceptions known between peculiar cyanobacteria species that are capable to also use FR light. To assess the habitability of exoplanets orbiting Red Dwarf stars, the research team build up an innovative laboratory simulator to expose different cyanobacteria species to a Red Dwarf star simulated irradiation (M7 type) and compare their responses to those under solar lights (G2) an FR light. The results showed that all the different cyanobacterial species tested, both able or unable to utilize FR light, were capable to grow when exposed for up to 10 days to the M-dwarf light spectrum and to photosynthesize almost optimally under the peculiar light spectrum. These findings open new prospective for the search for life outside the solar system. The study was performed thanks to an interdisciplinary collaboration between Prof. Nicoletta La Rocca of the Department of Biology (DiBio), Dr. Riccardo Claudi of the Astronomic Observatory/INAF (INAF/OAPD) and Dr. Luca Poletto of the Institute for photonics and nanotechnologies of CNR (IFN-CNR) in Padova.
Link: https://doi.org/10.3390/life11010010 “Super-Earths, M Dwarfs, and Photosynthetic Organisms: Habitability in the Lab”, di R. Claudi, E. Alei, M. Battistuzzi, L. Cocola, M. S. Erculiani, A. C. Pozzer, B. Salasnich, D. Simionato, V. Squicciarini, L. Poletto e N. La Rocca
Fundings: The research was co-funded by ASI - the Italian Space Agency - through the ”Life in Space” project (ASI N. 2019-3-U.0); by the Progetti Premiali scheme (Premiale WOW) of the Italian national Ministry of Education, University, and Research; by the Department of Biology of University of Padova and the Institute for Photonics and Nanotechnologies of CNR through intramural grants.