Spectroscopic Studies on the Puga Hot Spring Deposits, Ladakh, an Astrobiological Martian Analog Site in India

Abstract

Introduction and BackgroundThe habitability of any planetary body is governed by its ability to sustain conditions favorable to life on parts of its surface or in its interior on geological timescales (Cockell et al., 2016). Habitability (as defined by Cockell et al., 2016) is contingent on a number of factors, such as the presence of surficial or subterranean liquid water, existence of a redox energy source and the presence of a number of critical elements essential to life (Domagal-

Aquificae overcomes competition by archaeal thermophiles, and crowding by bacterial mesophiles, to dominate the boiling vent-water of a Trans-Himalayan sulfur-borax spring

“…The small archaeal genetic diversity was contributed by Crenarchaeota/Thermoproteota, followed by Euryarchaeota (1479 and 647 CDSs respectively); unclassified Archaea accounted for 183 CDSs (Tables S1 and S2). While the Crenarchaeota related CDSs were not classifiable further, the Euryarchaeota-affiliated CDSs were distributed over the classes Halobacteria (177), Thermococci (169), Archaeoglobi (83), Methanococci (60), Methanomicrobia (30), Methanobacteria (19) and Thermoplasmata (9); unclassified Euryarchaeota accounted for 100 CDSs (Tables S1 and S2). Most of the putatively eukaryotic CDSs detected exhibited highest sequence similarities with homologs from Opisthokonta, affiliated to either Fungi or Metazoa (Table S1).…”

“…Despite a considerable progress in our understanding of the geobiology of Trans-Himalayan sulfurborax springs, we still do not have any quantitative idea about the composition of the vent-water microbiomes of these astrobiologically significant hydrothermal systems [16,28,29]. Although we have a fair measure of the microbial diversity in terms of the variety of taxa present, we are completely unaware of the relative abundance of the individual taxa constituting the microbiome.…”

“…Despite a considerable progress in our basic awareness about the peculiar geobiology of Trans-Himalayan sulfur-borax hot springs, we still do not have any quantitative idea about the structural and functional dynamics of the vent-water microbiomes of these astrobiologically significant hydrothermal systems [16, 31, 32]. For instance, we have a fair measure of the microbial diversity in terms of the variety of taxa present, but we are completely uninformed about the relative abundance and temporal consistency of the individual taxa constituting the microbiome, the thermal adaptations of the native microorganisms (especially the phylogenetic relatives of mesophilic bacteria present), and the mutual interactions of the various components of the microbiome.…”