Strain Y74^T was an isolate from the sandy soil in the town of Huatugou, Qinghai–Tibet Plateau, China. An analysis of this strain's phenotypic, chemotaxonomic, and genomic characteristics established the relationship of the isolate with the genus Planococcus. Strain Y74^T was able to grow between 4 and 42°C (with an optimum temperature of 28°C) at pH values of 6–8.5 and in 0%–7% (w/v) NaCl. The dominant quinones were MK‐8 and MK‐7. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, and an unknown phospholipid. The majority of the fatty acid content was anteiso‐C_15:0 (28.8%) followed by C_16:1 ω7c alcohol (20.9%) and iso‐C_14:0 (13.4%). The 16S rRNA gene sequence similarity analysis demonstrated a stable branch formed by strain Y74^T and Planococcus halotolerans SCU63^T (99.66%). The digital DNA–DNA hybridization between these two strains was 57.2%. The G + C content in the DNA of Y74^T was 44.5 mol%. In addition, the morphological, physiological, and chemotaxonomic pattern clearly differentiated the isolates from their known relatives. In conclusion, the strain Y74^T (=JCM 32826^T = CICC24461^T) represents a novel member of the genus Planococcus, for which the name Planococcus antioxidans sp. nov. is proposed. Strain Y74^T was found to have potent antioxidant activity via its hydrogen peroxide tolerance and its 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical‐scavenging activity. The DPPH radical‐scavenging activity was determined to be 40.2 ± 0.7%. The genomic analysis indicated that six peroxidases genes, one superoxide dismutase gene, and one dprA (DNA‐protecting protein) are present in the genome of Y74^T.

Mount Everest provides natural advantages to finding radiation-resistant extremophiles that are functionally mechanistic and possess commercial significance. (1) Background: Two bacterial strains, designated S5-59T and S8-45T, were isolated from moraine samples collected from the north slope of Mount Everest at altitudes of 5700m and 5100m above sea level. (2) Methods: The present study investigated the polyphasic features and genomic characteristics of S5-59^T and S8-45^T. (3) Results: The major fatty acids and the predominant respiratory menaquinone of S5-59^T and S8-45^T were summed as feature 3 (comprising C16:1 ω6c and/or C16:1 ω7c) and ubiquinone-10 (Q-10). Phylogenetic analyses based on 16S rRNA sequences and average nucleotide identity values among these two strains and their reference type strains were below the species demarcation thresholds of 98.65% and 95%. Strains S5-59^T and S8-45^T harbored great radiation resistance. The genomic analyses showed that DNA damage repair genes, such as mutL, mutS, radA, radC, recF, recN, etc., were present in the S5-59^T and S8-45^T strains. Additionally, strain S5-59^T possessed more genes related to DNA protection proteins. The pan-genome analysis and horizontal gene transfers revealed that strains of Sphingomonas had a consistently homologous genetic evolutionary radiation resistance. Moreover, enzymatic antioxidative proteins also served critical roles in converting ROS into harmless molecules that resulted in resistance to radiation. Further, pigments and carotenoids such as zeaxanthin and alkylresorcinols of the non-enzymatic antioxidative system were also predicted to protect them from radiation. (4) Conclusions: Type strains S5-59^T (=JCM 35564T =GDMCC 1.3193T) and S8-45^T (=JCM 34749T =GDMCC 1.2715T) represent two novel species of the genus Sphingomonas with the proposed name Sphingomonas qomolangmaensis sp. nov. and Sphingomonas glaciei sp. nov. The type strains, S5-59^T and S8-45^T, were assessed in a deeply genomic study of their radiation-resistant mechanisms and this thus resulted in a further understanding of their greater potential application for the development of anti-radiation protective drugs.

The sustainable development of arid regions is significantly constrained by the availability of water resources, which play a crucial role in this context. It is necessary to deeply investigate and analyze the hydrochemical characteristics and major ion sources. This study, which was based on data from 183 water samples collected from the Jinghe River Basin, provided a comprehensive analysis of the river water hydrochemistry. The results show that the average TDSs (total dissolved solids) was measured at 49.8 mg·L⁻¹. HCO₃⁻ (82.4%) and Ca²⁺ (77.1%) were the ions present in the highest abundances. The river water was classified as the HCO₃⁻-Ca²⁺ hydrochemical type. The Gibbs diagrams indicated that the ion composition was primarily influenced by rock weathering. Additionally, the Na-normalized molar ratio diagrams suggested that the chemical composition was primarily governed by the weathering and dissolution of silicate rocks, while the carbonate rock dissolution played a lesser role. This study demonstrates a critical aspect of water resources quality evaluation, which is of great significance for the sustainable development, utilization and environmental protection of regional water resources.