Search

THE ''LIfe in Space'' project was funded in the wake of the Italian Space Agency's proposal for the development of a network of institutions and laboratories conceived to implement Italian participation in space astrobiology experiments. Of primary concern for this project is the study of the origin of life in the Universe, a focus that will promote investigation into prebiotic chemistry in various possible scenarios, whether in polar or nonpolar solvents (e.g., Titan's environment). Such results will link with study of the effects of simulated space conditions on possible chemical bio- signatures. The limits of life as we know it will be investigated in ground-based experiments with microorganisms that have already demonstrated their resistance to extreme environments on Earth and to real or simulated space conditions. The potential survival of microorganisms will also be examined with up-to-date molecular methods. The ability of some microorganisms to produce atmospheric and surface biosignatures when exposed to simulated conditions will be tested and compared with the possible existence of bio- signatures on potentially habitable exoplanets. Furthermore, the search for potentially habitable exoplanets, with space- based observational methods, will be optimized by way of dedicated climate models with the capacity to predict the detectability of atmospheric biosignatures for a broad range of planetary conditions. The project embraces the four most important topics in astrobiological research, as listed below, along with relevant contributions from the participating Italian institutions. Origins and evolution of organic compounds of biological significance in space (comets, asteroids, rocky planets, and moons); Prebiotic syntheses, origin of life, and early life; The limits of life and biological habitability: origin, evolution and adaptation of life in extreme environments on Earth and in space; Biomarkers for life detection in the Solar System and on exoplanets.

Photosynthetic organisms use sunlight as the primary source of energy to support their metabolism. In eukaryotes, reactions responsible of the conversion of light into chemical energy occur in specific organelles, the chloroplasts. In this study, we showed that mitochondria also have a seminal influence on cells' energy metabolism and on photosynthetic reactions. This is illustrated by the observation that the strong photosensitivity of

Bioindicators are organisms able to provide indirectly or directly information on the impact of pollutants in the environment. The content of heavy metals or other toxic compounds in these living organisms is of great interest to assess the level of contaminants. Leaves of the most common deciduous trees (Acer pseudoplatanus L., Betula pendula Roth, Carpinus betulus L., Cercis siliquastrum L., Ginkgo biloba L., Liquidambar styraciflua, Quercus robur L. and Tilia cordata Miller) and two invasive tree species Ailanthus altissima P. Mill. and Robinia pseudoacacia L., in the City of Bolzano (southern Alps in Northern Italy), were therefore studied to assess their suitability as bioindicators for the trace elements Cd, Cu, Mn, Pb, and Zn, mainly considered as traffic related elements. Leaves and soil samples were investigated, both from high-density traffic roads and control sites of minor traffic impact, such as parks. Our data reveal that Betula pendula has a considerable Zn accumulation potential compared to the other investigated tree species. The maximum value measured for Zn in a Betula specimen is 200 mg kg-1 dry weight. With regard to the soils, considering the geoaccumulation index, most of the analyzed soils belong to the first class, i. e. uncontaminated (Igeo ≤ 0) for all analyzed elements. Moreover, in several samples collected in high traffic areas, Cu and Zn show values within 1 < Igeo ≤ 2 (moderately contaminated). This allows to hypothesize a traffic-related origin for these elements. For this reason, B. pendula can be considered a potential heavy metal accumulator and therefore a good bioindicator for these urban pollutants. Since B. pendula is widely distributed in urban areas in Central and Northern Europe, it can be considered a species suitable for a systematic and comparative monitoring network. Bioindikatoren sind Organismen, die Informationen über die Auswirkungen von Schadstoffen in der Umwelt direkt oder indirekt bereitstellen. Den Gehalt von Schwermetallen und anderen toxischen Verbindungen in diesen Organismen zu bestimmen, ist von großem Interesse, um die Schadstoffbelastung der Umwelt zu bewerten. Daher wurden Blätter der häufigsten Laubbäume entlang der Straßen in der Stadt Bozen (S-Alpen in Norditalien) untersucht, namentlich von Acer pseudoplatanus L., Ailanthus altissima P. Mill., Betula pendula Roth, Carpinus betulus L., Cercis siliquastrum L., Ginkgo biloba L., Liquidambar styraciflua, Quercus robur L., Robinia pseudoacacia L. und Tilia cordata Miller, um deren Eignung als Bioindikatoren für die Spurenelemente Cd, Cu, Mn, Pb und Zn zu bewerten. Blätter und Bodenproben von Straßen mit hoher Verkehrsbelastung wurden mit denen mit geringer Verkehrsbelastung (z. B. Parks) verglichen. Unsere Daten belegen, dass Betula pendula ein erhebliches Akkumulationspotenzial von Zn im Vergleich zu den anderen untersuchten Baumarten hat. Der Maximalwert für Zn in einer Blattprobe der Birke beträgt 200 mg kg-1 Trockengewicht. Bezüglich des bodenkundlichen geoaccumulation index gehören die meisten der untersuchten Böden für alle analysierten Elemente zur ersten Klasse, das heißt „unbelastet“ (Igeo ≤ 0). Allerdings weisen Proben von stark verkehrsbelasteten Straßen Cu- und Zn-Werte von 1 < Igeo ≤ 2, d. h. „mäßig belastet“ auf. Dies lässt auf die Herkunft dieser Elemente aus dem Straßenverkehr schließen. Mit ihrer Eigenschaft Schwermetalle anzureichern, wurde die Birke (B. pendula) als ein potenzieller Bioindikator in Städten identifiziert. Da B. pendula in Stadtgebieten Mittel- und Nordeuropas weit verbreitet ist, scheint die Art für ein systematisches und vergleichendes Monitoring geeignet zu sein.