Influence of osmotic stress on desiccation and irradiation tolerance of (hyper)-thermophilic microorganisms

Abstract

This study examined the influence of prior salt adaptation on the survival rate of (hyper)-thermophilic bacteria and archaea after desiccation and UV or ionizing irradiation treatment. Survival rates after desiccation of Hydrogenothermus marinus and Archaeoglobus fulgidus increased considerably when the cells were cultivated at higher salt concentrations before drying. By doubling the concentration of NaCl, a 30 times higher survival rate of H. marinus after desiccation was observed. Under salt stress, the compatible solute diglycerol phosphate in A. fulgidus and glucosylglycerate in H. marinus accumulated in the cytoplasm. Several different compatible solutes were added as protectants to A. fulgidus and H. marinus before desiccation treatment. Some of these had similar effects as intracellularly produced compatible solutes. The survival rates of H. marinus and A. fulgidus after exposure to UV-C (254 nm) or ionizing X-ray/gamma radiation were irrespective of the salt-induced synthesis or the addition of compatible solutes.

High Tolerance of Hydrogenothermus marinus to Sodium Perchlorate

“…Previous studies showed that H. marinus is very tolerant to high salinity. The addition of NaCl (up to 1.2 M) during growth leads to formation and accumulation of compatible solutes and an elevation of desiccation tolerance in H. marinus (Beblo-Vranesevic et al, 2017). For some halotolerant strains, an influence of the counter ions can be neglected (Al Soudi et al, 2017).…”

“…In general, H. marinus unites some properties which are of essential importance when discussing the past and present habitability of Mars: the organisms can only grow at low oxygen concentrations (down to 0.5 vol % O 2 , Stöhr et al, 2001), the Martian atmosphere contains today an average oxygen concentration of 0.13% (Horneck, 2000); the cells are able to grow in the presence of Martian concentrations of perchlorates in combination with an exceptional desiccation tolerance (Beblo et al, 2009); they are tolerant to salt concentrations up to 1.2 M (Stöhr et al, 2001; Beblo-Vranesevic et al, 2017); the organism shows survival after exposure to UV-C and ionizing radiation (Beblo et al, 2011). The radiation dose rate of ionizing radiation on the surface of Mars was measured and calculated to be up to 0.21 mGy per day (Hassler et al, 2014; Matthiä et al, 2016) and is therefore significantly lower than in the applied experiments.…”

“…Because of its desiccation tolerance, the deep-branching microaerophilic bacterium Hydrogenothermus marinus proved to be a promising model organism in many respects. H. marinus exhibits a unique tolerance to desiccation and to exposure to elevated salt concentrations (Beblo et al, 2009; Beblo-Vranesevic et al, 2017). Therefore, it was hypothesized that this organism would survive and grow in the presence of perchlorates.…”

The role of compatible solutes in desiccation resistance of Acinetobacter baumannii

“…However, when the mutant was grown in mineral medium and dried in water, survival rates were similar to the wild type (Figure 7), indicating that production of the compatible solutes mannitol and trehalose is not beneficial under these conditions. We hypothesized that the solutes could be required when bacteria were dried in a moderate salt concentration, as evaporation of the water increases the concentration, which might lead to the need for protective solutes as in other bacteria (Beblo-Vranesevic, Galinski, Rachel, Huber, & Rettberg, 2017;Bonaterra, Camps, & Montesinos, 2005;Reina-Bueno et al, 2012;Welsh & Herbert, 1999). Yet, drying in saline instead of water did not affect dying of the wild type nor of the mutant (data not shown).…”

Introductory Chapter: A Brief Overview of Archaeal Applications

“…Potential applications of Archaea were subdivided into four ields (commercial enzymes and/or molecules (stars), environment (circles), food (triangles) and health (squares)) based on the reference(s) listed following each species. Thirty eight (n=38) archaeal species were integrated into the above phylogenetic tree (one DPANN species (white color), 21 Euryarchaeota species (dark grey color), 16 TACK species (light grey color)): Acidianus hospitalis W1 (NC_015518) [34,35], Acidilobus saccharovorans 345-15 (NC_014374) [36,37], Aeropyrum camini JCM 12091 (NC_121692) [38], Aeropyrum pernix K1 (NC_000854) [39], Archaeoglobus fulgidus DSM 4304 (NC_000917) [40,41], Caldivirga maquilingensis IC-167 (NC_009954) [42], Desulfurococcus fermentans DSM 16532 (NC_018001) [43], Desulfurococcus mobilis DSM 2161 (NC_014961) [44], Ferroglobus placidus DSM 10642 (NC_013849) [45], Fervidicoccus fontis Kam940 (NC_017461) [46], Halobacterium salinarum R1 (NC_010364) [47], Halobacterium sp. NRC-1 (NC_002607) [48], Haloferax mediterranei ATCC 33500 (NC_017941) [49], Halogeometricum borinquense DSM 11551 (NC_014729) [50], Halorhabdus utahensis JCM 11049 (NC_013158) [51], Halostagnicola larsenii XH-48 (NZ_CP007055) [52], Haloterrigena turkmenica DSM 5511 (NC_013743) [53], Metallosphaera cuprina Ar-4 (NC_015435) [54], Metallosphaera sedula DSM 5348 (NC_009440) [55], Methanocaldococcus jannaschii DSM 2661 (NC_000909) [27,56], Methanotorris igneus DSM 5666 (NC_015562) [57], Natrialba magadii ATCC 43099 (NC_013922) [58], Nanoarchaeum equitans Kin4-M (NC_005213) [59,60], Pyrobaculum aerophilum IM2 (NC_041958) [61,62], Pyrobaculum calidifontis JCM 11548 (NC_009073) [63], Pyrobaculum sp.…”