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Fiber optic sensors for monitoring scale deposition in geothermal brine and hot spring water should be safe, easily fabricated, and readily disposable. These desired features already have been enhanced in plastic optical fibers (POFs) and U-shaped sensors for other applications. The present work reports a U-shaped POF sensor for CaCO 3 scale deposition. The sensors were easily fabricated by thermally bending the bulk POF without removing the cladding. At the bend, the percentage of total internal reflection between the water and the POF surface is affected by the high refractive index of the CaCO 3 deposit. The optical responses of the U-shaped sensor to CaCO 3 formation were investigated in a mixture of calcium chloride dehydrate and sodium hydrogen carbonate using a white-light source and a spectroscopic detector. The sensor was responsive to CaCO 3 formation on the sensor surface and was especially sensitive at small bending radii. The sensitivity was further enhanced by increasing the number of bends. Finally, the U-shaped POF sensor was applied to the monitoring of CaCO 3 scale deposition in hot spring water sampled at Matsushiro, Japan., (© 2022. The Author(s), under exclusive licence to The Japan Society for Analytical Chemistry.)

Background: Empirical evidences for efficacy of hot spring (HS) water in inflammatory skin disorders have not been substantiated with sufficient, immunological "hard evidence". Mageumsan HS water, characterized by its weakly-alkaline properties and low total dissolved solids content, has been known to alleviate various immune-inflammatory skin diseases, including atopic dermatitis (AD)., Objective: The trial attempted to quantitatively analyze in vitro expression levels of chemical mediators in cutaneous inflammation from HaCaT cell line treated with Mageumsan HS, and suggest the likely mode of action through which it exerts the apparent anti-inflammatory effects in AD., Methods: Using membrane-based human antibody array kit, customized to include 30 different, keratinocyte-derived mediator proteins, their expression levels (including interleukin [IL]-1, IL-6, IL-8, thymic stromal lymphopoietin, thymus and activation-regulated chemokine, and granulocyte macrophage colony-stimulating factor) were assessed in vitro . Selected key proteins were further quantified with enzyme-linked immunosorbent assay., Results: There was a clear pattern of overall suppression of the mediators, especially those noted for their pro-inflammatory role in AD (monocyte chemoattractant protein [MCP]-1, regulated on activation, normal T cell expressed and secreted, cutaneous T-cell-attracting chemokine, Eotaxin, and macrophage inflammatory protein-1α, etc.). Also, reduced expression of involucrin and cytokeratin 1 was also reduced in the HS-treated group., Conclusion: The present study has shown that Mageumsan HS water may exert its effects on inflammatory skin disorders through regulation of proinflammatory cytokines. These evidences are to be supported with further future investigations to elucidate immunological mechanism behind these beneficial effects of HS water in the chronically inflamed skin of AD., Competing Interests: CONFLICTS OF INTEREST: The authors have nothing to disclose.

Several factors influence bacteria biodiversity in hot springs. The impact of biotic and abiotic pathways on travertine deposition plays a key role in microbial ecology and in the final composition of the waterborne microbiota. The metabolism of some bacterial groups such as photoautotrophs or lithoautotrophs influences water chemistry, favoring carbonate precipitation processes. The role of microbial mats in mineral precipitation processes is not fully clarified. For the first time, a comprehensive metagenomic analysis has been undertaken in the historical Bullicame hot spring. Bacterial biodiversity was characterized and biomineralization activities were assigned to different genera. A higher biodiversity in mat samples compared to water samples was observed: Shannon index of 3.34 and 0.86, respectively. Based on the functional assignment of each Operational Taxonomic Unit, the bacteria involved in biologically- induced mineralization are prevalent in mat and released in the water. According to the principle that each geothermal water specimen has distinctive physic-chemical characteristics, our results suggest new interacting bio-actions within these ecosystems. The saturation index and the chemical composition, as the high concentration of sulfur species and HCO3, can be linked to create a selective environment where pioneer communities are able to live and shape the ecosystem.

Background: In Tunisia, the use of hot spring waters for both health and recreation is a tradition dating back to Roman times. In fact, thermal baths, usually called "Hammam" are recommended as a therapeutic and prophylactic measure against many types of illness and toxicity. While the chemical concentration of thermal water is admittedly associated with its therapeutic effects, the inclusion in spa waters of efficient bioproduct additives produced by photosynthetic microorganisms and that act against oxidative stress may comprise a significant supplementary value for thermal centers. The aim of this study was to investigate the antioxidant potential of the Tunisian thermophilic cyanobacterium Leptolyngbya sp. and to determine its phytochemical constituents and phenolic profile., Methods: BME (Biomass Methanolic Extract), CME (Capsular polysaccharides Methanolic Extract) and RME (Releasing polysaccharides Methanolic Extract) of Leptolyngbya sp. were examined for their antioxidant activities by means of DPPH, hydroxyl radical scavenging and ferrous ion chelating assays. Their total phenols, flavonoids, carotenoids, Mycosporine-like amino acids (MAAs) and vitamin C contents, as well as their phenolic profiles were also determined., Results: BME has the highest content of phenols (139 ± 1.2 mg/g), flavonoids (34.9 ± 0.32 mg CEQ/g), carotenoids (2.03 ± 0.56 mg/g) and vitamin C (15.7 ± 1.55 mg/g), while the highest MAAs content (0.42 ± 0.03 mg/g) was observed in CME. BME presented both the highest DPPH and hydroxyl radical scavenging ability with an IC 50 of 0.07 and 0.38 mg/ml, respectively. The highest ferrous chelating capacity was detected in CME with an IC 50  = 0.59 mg/ml. Phenolic profiles revealed the presence of 25 phenolic compounds with the existence of hydroxytyrosol, oleuropein, resveratrol and pinoresinol., Conclusion: The study demonstrated that the cyanobacterium Leptolyngbya sp. possesses abundant natural antioxidant products which may have prophylactic and therapeutic effects on many types of illness and toxicity. The present findings not only explain and reinforce the rationale behind traditional therapeutic practices in Tunisia in the exploitation of the country's hot springs, but support the addition of Leptolyngbya to thermal waters as a means to enhance the value and reputation of the curative nature of Tunisian thermal waters.

Strain L-47(T) of a novel bacterial species belonging to the genus Legionella was isolated from a sample of hot spring water from Tokyo, Japan. The 16S rRNA gene sequences (1477 bp) of this strain (accession number AB899895) had less than 95.0% identity with other Legionella species. The dominant fatty acids of strain L-47(T) were a15:0 (29.6%) and the major ubiquinone was Q-12 (71.1%). It had a guanine-plus-cytosine content of 41.5 mol%. The taxonomic description of Legionella thermalis sp. nov. is proposed to be type strain L-47(T) (JCM 30970(T)  = KCTC 42799(T))., (© 2016 The Societies and John Wiley & Sons Australia, Ltd.)