Genomic Analysis of Haloarchaea from Diverse Environments, including Permian Halite, Reveals Diversity of Ultraviolet Radiation Survival and DNA Photolyase Gene Variants

• Published in: Microorganisms (Basel) Vol. 11; no. 3; p. 607
• Main Authors: Nag, Sagorika, DasSarma, Priya, Crowley, David J, Hamawi, Rafael, Tepper, Samantha, Anton, Brian P, Guzmán, Daniel, DasSarma, Shiladitya
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 28-02-2023; MDPI
• Subjects: Adaptation (Physiology); Amino acids; archaea; Astrobiology; Biological diversity; Composition; Deoxyribonucleic acid; Deposits; DNA; Earth; Exposure; extremophiles; Flats (landforms); Genes; Genetic aspects; Genetic variation; Genomes; Genomic analysis; Halites; Haloarchaea; halophile; Halophilic bacteria; Irradiance; Lake sediments; Lakes; Mars surface; Microbial enzymes; Microbiological research; Microorganisms; Natural history; Permian; Photolyase; Phylogenetics; Physiological aspects; Physiology; Proteins; radiation; Rock-salt; Salt flats; solar radiation; stratosphere; Survival; Ultraviolet radiation; Bolivia; United States > US; solar radiation; halophile; radiation; stratosphere; extremophiles; archaea
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms11030607

Ultraviolet (UV) radiation responses of extremophilic and archaeal microorganisms are of interest from evolutionary, physiological, and astrobiological perspectives. Previous studies determined that the halophilic archaeon,
sp. NRC-1, which survives in multiple extremes, is highly tolerant of UV radiation. Here,
sp. NRC-1 UV tolerance was compared to taxonomically diverse Haloarchaea isolated from high-elevation salt flats, surface warm and cold hypersaline lakes, and subsurface Permian halite deposits.
/
spp. from subsurface halite deposits were the least tolerant after exposure to photoreactivating light. This finding was attributed to deviation of amino acid residues in key positions in the DNA photolyase enzyme or to the complete absence of the photolyase gene. Several
and
species from surface environments exposed to high solar irradiance were found to be the most UV tolerant, and
from lake sediment was of intermediate character. These results indicate that high UV tolerance is not a uniform character trait of Haloarchaea and is likely reflective of UV exposure experienced in their environment. This is the first report correlating natural UV tolerance to photolyase gene functionality among Haloarchaea and provides insights into their survival in ancient halite deposits and potentially on the surface of Mars.