Identification of Salda lake archaeal composition by MinION sequencer to demonstrate possible microbial assemblance between martian environment and planet earth

Discovery of microbial life on another planet is crucial for demonstrating the existence of life precursors in space. According to data collected by the National Aeronautics and Space Administration (NASA), Lake Salda on Earth is an analogue for the Jezero crater, Mars. The study examines archaeal components of Lake Salda, which could provide clues to possible biosignatures on Martian surface. Archaea are considered the most primitive microorganisms. Amplicon sequencing employed to analyze archaeal species present in Lake Salda using MinION device from Oxford Nanopore Technologies. This research represents the first application of the MinION sequencer for analyzing archaeal community of the Lake. The samples collected during summer 2021, from sediments, biofilm, microbial mats, water filters, and moss, categorized based on their sampling location and composition. The findings indicated that the samples primarily consist of four superphyla of archaea: Thaumarchaeota (now referred to as Nitrososphaerota), Aigarchaeota, Crenarchaeota (now referred to as Thermoproteota), and Korarchaeota (collectively known as TACK), Euryarchaeota, Candidatus Thermoplasmatota, Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota (DPANN). The largest diversity was observed in sediment samples, whereas microbial mat samples exhibited the lowest diversity. No significant differences in diversity were observed among the samples based on location. Archaeal species identified in Lake Salda play significant role in biogeochemical cycles. Furthermore, optimal growth conditions for most of the identified species do not align with the environmental characteristics of Lake Salda. Understanding how these species adapt to suboptimal conditions and the mechanisms underlying this adaptation provides valuable insights into evolutionary biology and astrobiology.