Desiccation of the Extreme Thermoacidophile Metallosphaera sedula Grown on Terrestrial and Extraterrestrial Materials

Abstract

Prokaryotes are among the most versatile organisms on Earth and their ability to adsorb metals for nutrient, energy, or protection purposes can be noted in many different environments on our planet. The extreme thermoacidophilic archaeon Metallosphaera sedula is a metal-mobilizing archaeon capable of redox transformations during chemolithoautotrophic growth on diverse metal-bearing compounds. Examining the interfaces of this extreme metallophilic archaeon with various metal-bearing substrates of terrestrial and extraterrestrial origin, we have detected its selective preservation after desiccation. Cultivated on specific metal-bearing materials, e.g., tungsten-bearing scheelite, tungsten-bearing polyoxometalate, multimetallic waste products, and the NWA 1172 meteorite, cells of M. sedula can be preserved after dehydration, and therefore can potentially serve as a microbial fingerprint of the presence and/or activity of metal-transforming microorganisms. Preservation of desiccated M. sedula cells reported in this study has a discriminatory character, depending on the content and nature of the metal-containing compound used for cultivation of this metallophilic microorganism. The achieved preservation of dehydrated M. sedula cells facilitates our survivability studies with this desiccated microorganism during future space exposure experiments and under simulated space environmental conditions.

Water–Sulfuric Acid Foam as a Possible Habitat for Hypothetical Microbial Community in the Cloud Layer of Venus

“…The drying of water bodies at the significant elevation of temperature undoubtedly was accompanied by a strong increase in salt concentrations. According to the data obtained, the clouds of Venus contain up to 75% sulfuric acid [2][3][4]17]. Under such extreme conditions, a strong selection for extreme acidophilic organisms might have occurred [23][24][25][26].…”

“…The discovery of an unknown compound within Venusian clouds, the UV absorption spectrum of which was similar to that of biomacromolecules, has significantly supported this habitability concept [13,14]. Recently, all the ideas related to hypothetical Venusian microorganisms and their possible biochemical properties were summarized [5,[15][16][17][18]. Astrobiologists consider Venusian clouds to be a habitable environment for extreme forms of life similar to extremophiles on Earth based on a habitability concept that includes: (1) the presence of a solvent needed for biochemical reactions, (2) appropriate physicochemical conditions, (3) available energy sources, and (4) biologically relevant elements C N P S O H [8,18].…”

Siderite and vivianite as energy sources for the extreme acidophilic bacterium Acidithiobacillus ferrooxidans in the context of mars habitability

“…Considering its status as a model organism for bacterial iron oxidation, later studies also used A. ferrooxidans to access the capacity of other substrates to sustain its growth, like carbonaceous chondrites and metallic meteorites 20 . Nevertheless, it is important to note that other chemolithoautotrophic organisms have also been explored in this context, such as the archaeon Metallosphaera sedula with ordinary chondrites 21 and Martian meteorites 22 as substrates.…”