Hot Spring Water Research Articles

Aquificae overcomes competition by archaeal thermophiles, and crowding by bacterial mesophiles, to dominate the boiling vent-water of a Trans-Himalayan sulfur-borax spring.

Trans-Himalayan hot spring waters rich in boron, chlorine, sodium and sulfur (but poor in calcium and silicon) are known based on PCR-amplified 16S rRNA gene sequence data to harbor high diversities of infiltrating bacterial mesophiles. Yet, little is known about the community structure and functions, primary productivity, mutual interactions, and thermal adaptations of the microorganisms present in the steaming waters discharged by these geochemically peculiar spring systems. We revealed these aspects of a bacteria-dominated microbiome (microbial cell density ~8.5 × 104 mL-1; live:dead cell ratio 1.7) thriving in the boiling (85°C) fluid vented by a sulfur-borax spring called Lotus Pond, situated at 4436 m above the mean sea-level, in the Puga valley of eastern Ladakh, on the Changthang plateau. Assembly, annotation, and population-binning of >15-GB metagenomic sequence illuminated the numeral predominance of Aquificae. While members of this phylum accounted for 80% of all 16S rRNA-encoding reads within the metagenomic dataset, 14% of such reads were attributed to Proteobacteria. Post assembly, only 25% of all protein-coding genes identified were attributable to Aquificae, whereas 41% was ascribed to Proteobacteria. Annotation of metagenomic reads encoding 16S rRNAs, and/or PCR-amplified 16S rRNA genes, identified 163 bacterial genera, out of which 66 had been detected in past investigations of Lotus Pond's vent-water via 16S amplicon sequencing. Among these 66, Fervidobacterium, Halomonas, Hydrogenobacter, Paracoccus, Sulfurihydrogenibium, Tepidimonas, Thermus and Thiofaba (or their close phylogenomic relatives) were presently detected as metagenome-assembled genomes (MAGs). Remarkably, the Hydrogenobacter related MAG alone accounted for ~56% of the entire metagenome, even though only 15 out of the 66 genera consistently present in Lotus Pond's vent-water have strains growing in the laboratory at >45°C, reflecting the continued existence of the mesophiles in the ecosystem. Furthermore, the metagenome was replete with genes crucial for thermal adaptation in the context of Lotus Pond's geochemistry and topography. In terms of sequence similarity, a majority of those genes were attributable to phylogenetic relatives of mesophilic bacteria, while functionally they rendered functions such as encoding heat shock proteins, molecular chaperones, and chaperonin complexes; proteins controlling/modulating/inhibiting DNA gyrase; universal stress proteins; methionine sulfoxide reductases; fatty acid desaturases; different toxin-antitoxin systems; enzymes protecting against oxidative damage; proteins conferring flagellar structure/function, chemotaxis, cell adhesion/aggregation, biofilm formation, and quorum sensing. The Lotus Pond Aquificae not only dominated the microbiome numerically but also acted potentially as the main primary producers of the ecosystem, with chemolithotrophic sulfur oxidation (Sox) being the fundamental bioenergetic mechanism, and reductive tricarboxylic acid (rTCA) cycle the predominant carbon fixation pathway. The Lotus Pond metagenome contained several genes directly or indirectly related to virulence functions, biosynthesis of secondary metabolites including antibiotics, antibiotic resistance, and multi-drug efflux pumping. A large proportion of these genes being attributable to Aquificae, and Proteobacteria (very few were ascribed to Archaea), it could be worth exploring in the future whether antibiosis helped the Aquificae overcome niche overlap with other thermophiles (especially those belonging to Archaea), besides exacerbating the bioenergetic costs of thermal endurance for the mesophilic intruders of the ecosystem.

Effect of an 8-week hot spring water exercise program on body composition, knee isokinetic muscle function, range of motion, and the Korean Western Ontario and Mcmaster Universities index in middle-age females with osteoarthritis in Republic of Korea: experiment study

Effect of an 8-week hot spring water exercise program on body composition, knee isokinetic muscle function, range of motion, and the Korean Western Ontario and Mcmaster Universities index in middle-age females with osteoarthritis in Republic of Korea: experiment study

Coaggregation Occurs between a Piliated Unicellular Cyanobacterium, Thermosynechococcus, and a Filamentous Bacterium, Chloroflexus aggregans.

Cyanobacteria are widely distributed in natural environments including geothermal areas. A unicellular cyanobacterium, Thermosynechococcus, in a deeply branching lineage, develops thick microbial mats with other bacteria, such as filamentous anoxygenic photosynthetic bacteria in the genus Chloroflexus, in slightly alkaline hot-spring water at ~55 °C. However, Thermosynechococcus strains do not form cell aggregates under axenic conditions, and the cells are dispersed well in the culture. In this study, Thermosynechococcus sp. NK55a and Chloroflexus aggregans NBF, isolated from Nakabusa Hot Springs (Nagano, Japan), were mixed in an inorganic medium and incubated at 50 °C under incandescent light. Small cell aggregates were detected after 4 h incubation, the size of cell aggregates increased, and densely packed cell aggregates (100-200 µm in diameter) developed. Scanning electron microscopy analysis of cell aggregates found that C. aggregans filaments were connected with Thermosynechococcus sp. cells via pili-like fibers. Co-cultivation of C. aggregans with a pili-less mutant of Thermosynechococcus sp. did not form tight cell aggregates. Cell aggregate formation was observed under illumination with 740 nm LED, which was utilized only by C. aggregans. These results suggested that Chloroflexus filaments gather together via gliding motility, and piliated cyanobacterial cells cross-link filamentous cells to form densely packed cell aggregates.

Fiber Optic-Based Portable Sensor for Rapid Evaluation and In Situ Real-Time Sensing of Scale Formation in Geothermal Water

The formation of scale in hot springs and geothermal brines can be detected quickly and easily using optical fiber-based scale sensors. This paper describes the development of a portable sensor for the in situ detection of scale in geothermal water. This sensor was used to detect the formation of calcium carbonate and silica scale and to assess the effectiveness of their inhibitors. The performance of the sensor was evaluated using calcium carbonate scale. In laboratory experiments using both the newly developed sensor and a conventional nonportable sensor, the strength of the transmitted signal was found to decrease significantly as the amount of scale increased. It was considered that this sensor can accurately evaluate only scale formation without being affected by turbidity. The scale that was deposited on each material (optical fiber core, glass plate, polyvinyl chloride (PVC), and SUS304) was observed using a shape analysis laser microscope. Based on these observations, we concluded that this sensor could be used to predict the amount of scale deposited in real time. In situ evaluation of the sensor was conducted at a blowout carbonated hot spring on Rishiri Island, which is located off the coast of Hokkaido, Japan. The results obtained from experiments using hot spring water showed a similar sensor response within a comparable time range as those obtained from the laboratory experiments. The results of this study thus demonstrate that this novel portable scale sensor is suitable for use in geothermal power plants and investigating effectiveness of inhibiters under different conditions.

Harnessing a thermo-active and alkaline lipase from novel strain of Brevibacillus borstelensis gp-1, for application in biodiesel synthesis

A novel thermo-active and alkaliphilic strain of Gp-1, isolated from hot water springs of Ganeshpuri, Maharashtra, India, identified as Brevibacillus borstelensis based on 16SrDNA characterization, with accession no. MT292327, at NCBI database. Statistical optimization of lipase production was done using Plackett-Burman algorithm and response surface methodology. Fermentative production of Gp-1 lipase was followed by partial purification, with 24.10 fold purification. Gp-1 lipase has molecular mass of 31 kDa, as determined by SDS-PAGE. Gp-1 lipase exhibited maximal specific activity at pH 10 and 55 °C, with stability up to 70 °C. Kinetic parameters analysis revealed Gp-1 lipase has Km and Vmax values of 1.544 mM and 31.25 μM/mg. min, and specificity constant of 281.13 sec-1, with pNP caprylate as the base suited substrate. Gp-1 lipase was found to be retain more than 90% activity in presence of various organic solvents, and various commercial detergent formulations. The Gp-1 lipase was also tested for transesterification reactions, which revealed successful transesterification of coconut oil, olive oil and waste cooking oil, and conversion in esters. Hence, Gp-1 lipase stands out as a prospective candidate in biodiesel synthesis, a green energy alternative.

Fluid upwelling and alluvial controls on spring localization: An example from Sri Lanka

In water-scarce regions, perennial springs can be a valuable source of drinking water. However, to identify unreported springs and shallow water upwelling zones, it is essential to understand the factors that control spring localization. In a crystalline basement, as in Sri Lanka, without a sedimentary cover, faults and fractures provide the only far-reaching fluid pathways and springs commonly emerge at fault/fracture intersections. While surveying cold and hot water springs in Sri Lanka, it was observed that all springs probed were located at the edge of alluvium. In order to gain insight into this relationship, we performed a topographic and geomorphological analysis was conducted utilizing remote sensing, geological and soil maps, and geological mapping in the field. The results of our analysis of 27 springs indicate that their localization is controlled by fault intersections, non-permeable clay in the alluvium and laterite, and the chemically weathered surface of the bedrock. Furthermore, the constant discharge rates observed over the years and isotope analysis suggest that the springs are part of a tens-of-kilometer-wide regional groundwater system. Based on these results, we propose a conceptual model in which water rises at fault intersections from depth until it reaches the base of the alluvium where up to several meters thick clay with low to zero permeability further inhibits vertical flow forcing the water to spread laterally. Along the alluvium clay boundary with the more permeable weathered bedrock, the water continues its path to the surface. The localization of springs differs from that of fault intersection by tens of meters, with the potential for mixing between shallow and deep groundwater. This observed effect of alluvium and their contact boundaries on spring localization has not been reported for Sri Lanka. Consequently, discharge rates may be significantly increased if the fault intersections are specifically targeted by shallow drilling.

Plant growth promotion activities of Bacillus spp. isolated from Jakrem hot water spring of Meghalaya, North East India

The study aims to investigate plant growth promotion (PGP) activities of thermophilic bacteria isolated from the Jakrem hot spring in Meghalaya, North-East India, and determine their effect on Brassica juncea's growth. The bacteria were isolated by a culture-dependent approach following a serial dilution method in a nutrient agar medium. All the isolates were determined for PGP attributes such as indole acetic acid, phosphate solubilization, hydrolytic enzymes, and siderophore production. The potent bacterial isolates were characterized by 16S rDNA sequencing and phylogenetic analysis. Altogether, 53 bacterial isolates were obtained, most belonging to the genus Bacillus. Of the total isolates, 37.7% exhibited both PGP and hydrolytic enzyme activities. Three isolates, namely JAB1, JAB8, and JAB100, showed promising PGP and were identified as Bacillus velezensis, B. proteolyticus, and Bacillus sp., respectively. The PGP attributes of these isolates were determined in vivo on B. juncea, and their effects were measured in terms of shoot and root length biomass and biochemical contents. It was observed that combined inoculation of all three isolates significantly enhanced the growth and development of B. juncea, evident by increased shoot and root length, fresh and dry weight, and higher levels of protein, phenol, flavonoid, and chlorophyll content compared to the control. In conclusion, the study highlights the potential application of thermophilic Bacillus spp. from hot springs as bioinoculants to enhance crop productivity in sustainable agricultural practices.

Origin of Groundwater in Kawung Carang Cold Spring, Sumbang District, Banyumas Regency, Central Java

Abstract The occurrence of several springs around Slamet Volcano raised questions regarding their origin. Many studies have been conducted to understand the origin of hot spring water around Slamet Volcano. Meanwhile, there has not been any research on the origin and hydrogeological system of cold spring water around Slamet Volcano. Kawung Carang Spring is one of cold spring water that occurs on the southern flank of Slamet Volcano. It is situated in a quaternary volcanic deposit of Mt. Slamet formation. Field observation was conducted to identify local geological conditions and hydrogeological systems in the research area. Isotopic analysis was performed to help understand how to delineate the recharge area. This study used a physical-chemical analysis of Kawung Carang cold spring water and the ratio of deuterium (2H) and 18O stable isotopes to interpret its groundwater origin. The results of the analysis informed that the origin of Kawung Carang spring water was local meteoric water. The hydrogeological system was an unconfined aquifer that consisted of a lahar deposit on the top of a volcanic breccia layer. The physical-chemical characteristic of groundwater around the Kawung Carang cold spring shows low electric conductivity (EC) and total dissolved solids (TDS) values. EC and TDS values of groundwater vary from 92 to 253 µS/cm and 46 to 126 mg/L indicating that groundwater has a short time in water-rock interaction process and comes from shallow depth aquifer. Furthermore, the signature of stable isotopes of δ18O and δ2H shows the elevation of the Kawung Carang cold spring recharge area ranges from 386.08 to 441.37 meters above sea level in the northwestern part of the research area.

Thermal Culture as National Heritage Among the Algerian Population Case Study Hammam Debagh Guelma

The thermal culture in Algeria dates back to antiquity, the Romans were among the first to know the therapeuticbenefits of hot water springs in the region, Guelma is one of the Algerian cities which have natural hot springs, overfor centuries the thermal tradition has been perpetuated and has been integrated into the local medical culture. Theprofessional objective is to undertake an in-depth analysis of the thermal culture at Hammam Debagh, Guelma,capitalizing on its rich ancient heritage, and the attractiveness of the public in search of medical care, relaxation andleisure, thus highlighting the importance continues this age-old practice for health and well-being. A thoroughunderstanding of this tradition will help strengthen its attractiveness and promote its potential as a therapeutic andtourism resource.

GIS-based AHP model for selecting the best direct use scenarios for medium to low enthalpy geothermal resources with hot springs in central and Western Kenya

Medium to low enthalpy geothermal resources (MLEGRs) in various Eastern African countries, Djibouti, Ethiopia, Kenya, Uganda, Tanzania, Rwanda, and Malawi, have received little attention from policymakers in the energy sector. Policymakers from these countries prioritize developing high-enthalpy resources for electric power production. Hence, many MLEGRs remain unused since they are assumed to pose higher risks of drilling unproductive deep wells. Besides, funding institutions prioritize high-enthalpy geothermal resources. Some MLEGRs have warm-to-hot springs with considerable flow rates and chemical constituents with varying concentrations. This study introduces a novel approach, using hydrogeochemical analysis of hot spring waters and a GIS-based AHP model, to select the best direct use scenarios for the warm/hot springs emanating from MLEGRs in central and western Kenya. The model is validated by contemporary commercial usage of the hot springs and similar studies in the study area. The stable isotope analysis revealed that the hydrothermal systems in Kenya are majorly recharged by meteoric water. In contrast, Kenya Rift Valley endorheic lakes, such as Lake Naivasha, Lake Nakuru, Lake Magadi, Lake Baringo, Lake Bogoria, and Lake Turkana, partly recharge some. Hence, they pose low risks of drying up during development and exploitation for thermal energy. The over 150 hot springs in Kenya produce warm to hot water with a thermal capacity of over 275 MWt. Hence, by harnessing the hot spring resources, Kenya can raise its direct use capacity from the current 18.5 MWt to about 100–200 MWt without drilling shallow or deep wells. The hot springs best suited for domestic use and aquacultural pond heating were selected as Narosura, Majimoto, Olchorro, Kipsegon, Kijabe, and Eburru. Those best suited for spas, bathing/ swimming pools, and volcanic geotourism were Lake Bogoria, Arus, Homa Hills, and Kariandusi. Overall, Lake Bogoria, Homa Hills, and Narosura hot springs were rated the best for direct use of hot springs.

Hydrochemical Characterization, Geothermometry, and Origin of Ain Al-Harrah Hot Spring and Its Relationship to Al-Lith Geothermal System, Saudi Arabia.

The Al-Lith geothermal field in western Saudi Arabia is a characteristic medium-high enthalpy geothermal system, exhibiting features associated with tectonic activities linked to the Red Sea rifting. Ain Al-Harrah hot spring is located in the Al-Lith field, with discharge temperatures varying from 56 to 81 °C. The determination of water temperature and composition in a geothermal reservoir is critical to the design of utilization strategies, surface production facilities, and choice of materials. This research presents a comprehensive hydrochemical characterization of the Ain Al-Harrah hot spring and its relationship with the underlying geothermal system. This study was conducted in two main phases; first, the fieldwork involved the collection of water samples from the hot spring, measuring the temperature, pH, and electrical conductivity (EC) of the water. The second phase involved laboratory analyses of the collected samples, including major and trace element analyses, isotopic analysis, and geothermometry. The dominant hydrogeochemical processes in the region were determined by analyzing the hydrochemistry of the water samples. Thermal waters analyzed exhibited high concentrations of Na+ (410-463 mg/L), HCO3 - (64.48-90 mg/L), and Cl- (472.76-581.95 mg/L), intermediate levels of K+ (50.2-93.0 mg/L), and low levels of Mg2+ (1.27-2.04 mg/L). The total dissolved solids (TDS) concentration ranges between 1830 and 2055 mg/L. The hot spring is categorized as Na-HCO3 type facies that are moderately alkaline, with pH values ranging between 7.9 and 8.2. Analysis of trace element concentrations revealed that the hydrochemical processes were primarily governed by the abundance and solubility of trace elements in the rocks surrounding the hot spring, the pH, and the temperature of the hot spring water. The stable isotope data for δD (-12.36 to 15.21%) and δ18O (-2.84 to -3.38%) provided evidence that the thermal spring is of meteoric origin. Based on Na-K-Ca, K2/Mg, and quartz geothermometers, the temperature range of the reservoir was determined to be between 150 and 205 °C. The temperature range suggests a medium-to-high enthalpy geothermal system.

Natural radioactivity level in Yemen: A systematic review of radiological studies

This paper aimed to conduct a systematic review of 26 published articles from 13 different regions in the Republic of Yemen related to the study of natural radioactivity (NORM) and enhanced artificial radioactivity (TENORM). The study relied on the analysis of various sample types, including air, groundwater, surface water, hot spring water, soil, sand, rocks, building materials, and oil field samples. It also analyzed the study areas, the types of detectors employed, and the study's timeframe. The analytical results raised significant concerns regarding the high levels of radioactivity observed in many of the studied regions. Moreover, some regions indicated the absence of any prior radiological study, despite apparent effects on the population and the environment, which suggest the presence of potential radionuclide concentration. Based on this study, it is strongly recommended that researchers conduct further radiological studies in regions previously studied over extended periods and in areas where no prior radiological studies have been conducted to assess potential radionuclide concentration.

Sources, Fates, and Geochemical Cycling of Mercury in Geothermal Fields: Insights From Mercury Isotopes

AbstractGeothermal fields emit remarkable amounts of mercury (Hg) to the environment. To address the source, fate and geochemical cycling of Hg in geothermal fields, we investigated Hg concentrations and isotopic compositions of hot spring water and fumarole gases from Rehai and Dagejia in SW‐China. Elevated Hg concentrations in fumarole gases (10.0–167 ng m−3) and hot spring water (3.44–84.5 ng L−1) were observed, suggesting that both geothermal fields are of environmental concern. The variation in Δ199Hg (−0.06 to 0.23‰) and Δ200Hg (−0.09 to 0.19‰) in hot spring water supports Hg likely originating from endogenous volcanic degassing and/or rainwater. Negative and nearly zero Δ199Hg in fumarole gases (−0.32 to 0.03‰) supports volcanic degassing and background atmosphere origin. The ranges of δ202Hg in fumarole gases (−0.74 to 0.59‰) and hot spring water (−1.29 to 0.52‰) could reflect limited fluids boiling in geothermal fields. This study, thus, fills an important knowledge gap regarding Hg global cycling.

Utilization of Multi-Ionic Interaction of Yumoto Hot Springs for Enhancing the Moisturizing Properties of Hyaluronic Acid Sodium Salt

Hot spring (HS) waters manifest diverse positive effects on the skin due to their unique chemical compositions. Sodium hyaluronate acid (HA) comprises N-acetylglucosamine and D-glucuronic acid, and distinguishes itself with superior qualities in skin regeneration, providing moisturizing and anti-aging benefits. The combination of HA with HS water is widely applied across ophthalmology, pneumology, nutrition, and cosmetics. This study delved into the application of HA in cosmetology, with a focus on its interaction with HS water and its effects on moisture retention and promoting wound healing. In particular, with the alkaline pH levels of the Yumoto HS, HA molecules may undergo dissociation to be ionized resulting in a negatively charged polymer and interacting with positively charged ions in the HS water through electrostatic interactions. The shifted peaks in the FTIR result and zeta potential shifts to a less negative region in the case of HA-HS compared to HA-DI indicate an ionic interaction between HS water and HA. Moisture tests confirmed the sustained hydration when HA is dissolved in HS water, underscoring its potential to improve skin hydration at certain concentrations, specifically at 0.5% and 1%. Additionally, MTT assay results demonstrated that HS water stimulates the growth of fibroblast cells compared to distilled water, implying its potential beneficial effect in wound healing. These findings suggested the multifaceted benefits of HAHS in skincare, highlighting its role in enhancing skin hydration and potentially accelerating wound healing processes, thus presenting avenues for the development of advanced cosmeceutical formulations.

What are the growth kinetics and biochemical compositions of microalgae isolated from diverse aquatic ecosystems in Morocco, France, and Tunisia?

Thirty-six microalgae belonging to five taxonomic groups (Cyanobacteria, Chlorophyceae, Diatomophyceae, Euglenophyceae, and Eustigmatophyceae) were identified from six freshwater ecosystems in Morocco, two treatment stations in Etueffont landfill in France and three hot spring waters in Tunisia. Investigations on species growth kinetics and growth rates showed that the cyanobacterium Leptolyngbya gelatinosa exhibited both the highest biomass and growth rate with 4 g DW L-1 and 0.282 day-1, respectively. A significant protein production (more than 40% DW) was observed across the studied species. Cyanobacteria and chlorophytes stood out for their increased protein production with a maximum (66.63 ± 3.84% DW) attained by the cyanobacterium Leptolyngbya sp. Chlorophytes produced substantial amounts of carbohydrates (more than 20% DW). Euglenophytes including Phacus orbicularis and Euglena ehrenbergii along with the chlorophyte Graesiella sp. accumulated significant amounts of lipids (up to 31.12% DW).

Geochemical characteristics of hot springs in active fault zones within the northern Sichuan-Yunnan block: Geochemical evidence for tectonic activity

The geochemistry of the fluids is spatially closely related to faults and earthquakes that have been detected in the northern Sichuan-Yunnan (SC-YN) block. However, the processes and factors that control hydrothermal fluid circulation on a regional scale remain challenging. The geochemical circulation of the hot springs integrated with geological and geophysical data revealed the processes and controlling factors of the relationship between fluid circulation and tectonic activity. Our results showed that the hydrochemical type of the hot springs at the intersection of the Yushu-Ganzi fault (YS-GZF), Xianshuihe fault (XSHF) and Yunongxi fault (YNXF), Jinshajiang fault (JSJF) and Batang fault (BTF) as well as Ganzi-Litang fault (GZ-LTF) is composed of Na-HCO3 and Na-HCO3·Cl. It demonstrated higher reservoir temperature and circulation depth (5 − 7 km). The helium isotope (0.22 − 2.36 Ra) of the gas indicated that the mantle helium composition was up to 5 − 30 %. These hot springs may undergo water–rock-gas exchange reactions with deep fluids. Considering geological and geophysical background as well as previous studies, the geochemical characteristics of the hot spring at the intersections of faults in the north of the SC-YN block are thought to be controlled by the deep-driven upwelling lower crustal flows, mixing with shallow hot spring water and the temporal and spatial heterogeneity of the high strain fields, slip rates, and permeability of the fault intersections. Whereas, the transport of fluids in hot springs of fault may increase pore fluid pressure, and reduce the effective stress at the intersection of the fault zones, which can promote fault sliding and provoke seismic events as well as fault movements. It could result in the enhancement of regional tectonic activity. This study provides an important basis for seismic prediction with hot spring hydrochemistry stations.

Lipophilic bioactive compounds from thermophilic cyanobacterium Leptolyngbya sp. HNBGU-004: Implications for countering VRSA resistance

Extremophiles thrive in extreme conditions, showcasing rich and unexplored diversity. This resilience hints at the existence of novel biochemical pathways and unique bioactive compounds. In contrast, the issue of drug resistance and excessive misuse of antibiotics in various settings, such as healthcare, agriculture, and veterinary medicine, has contributed to the emergence and spread of drug-resistant microorganisms.In the present research, Leptolyngbya sp. HNBGU-004, was obtained from an extreme location, a hot water spring in the Garhwal Himalayan region of India. The lipophilic fraction derived from Leptolyngbya sp. HNBGU-004 exhibited significant inhibitory effects against vancomycin-resistant Staphylococcus aureus (VRSA), displaying a bactericidal concentration of 0.5 mg mL−1. Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis of the lipophilic extract unveiled the major constituents.Leptolyngbya sp. HNBGU-004 holds significant promise as a primary source of potent anti-vancomycin-resistant S. aureus components. These findings emphasize the importance of Leptolyngbya sp. HNBGU-004 as a foundational source for use as both a synergistic and alternative agent against VRSA.

An Autonomous Thermal Camera System for Monitoring Fumarole Activity.

The Kenyan part of the East African Rift System hosts several geothermal fields for energy production. Changes in the extraction rate of geothermal fluids and the amount of water re-injected into the system affect reservoir pressure and production capacity over time. Understanding the balance of production, natural processes and the response of the geothermal system requires long-term monitoring. The presence of a geothermal system at depth is often accompanied by surface manifestations, such as hot water springs and fumaroles, which have the potential for monitoring subsurface activity. Two thermal camera timelapse systems were developed and installed as part of a multi-sensor observatory in Kenya to capture fumarole activity over time. These cameras are an aggregation of a camera unit, a control unit, and a battery charged by a solar panel, and they monitor fumarole activity on an hourly basis, with a deep sleep of the system in between recordings. The article describes the choice of hardware and software, presents the data that the cameras acquire, and discusses the system's performance and possible improvement points.

Multi-isotopes (H, O, Sr, and Li) and element geochemistry constrain the formation of Kongchutso helium-rich geothermal field in western Tibet, China

The Kongchutso geothermal field hosts helium-rich hot springs with helium contents (up to 1.54 vol.%) higher than industrial grade of He resources (0.05 – 0.1 vol.%). However, the geochemical signature of helium-rich geothermal fluids, reservoir feature, and their genesis remain poorly understood. Here, we present element geochemistry (major and trace elements) and multi-isotopes (H, O, Sr, and Li) compositions of hot and cold springs, lake, calcareous sinters, and rocks from Kongchutso to determine the formation mechanism of helium-rich geothermal system. The major elements studies of water samples show that most helium-rich hot spring waters belong to the Na-HCO3-Cl type, possibly affected by water-rock interaction in the deep and mixing of geothermal fluids with groundwater in the shallow. Based on chalcedony geothermometers and silica enthalpy mixing model, the reservoir temperature has been calculated to be 106 – 118 °C. The H and O isotopic compositions of water samples manifest that the Kongchutso geothermal system was recharged by snow-melt water and meteoric precipitation from the surrounding mountains at an elevation of 5366 m. The widespread Cretaceous granites in the region featured by high enrichment of uranium (up to 34.15 ppm) and thorium (up to 37.49 ppm) are considered as helium and heat sources, and also are reservoir rocks. The interpretation is supported by consistent signatures of rare earth elements and Sr-Li isotopes for waters, calcareous sinters, and granites. Therefore, we suggest that the helium was initially generated via radioactive decay by U-Th in granites and then dissolved in the deep circulated and heated meteoric waters, and finally ascended to surface through the main fault systems to form the helium-rich hot springs at Kongchutso. Some other hydrothermal manifestations, such as calcareous sinters, formed accompanying the fluids migrated to the surface. Based on these new findings, we further proposed that high radioactive granite, together with tectonic system and surface hydrothermal manifestations can be used as indicators for exploration of helium-rich geothermal resources in Tibet and elsewhere in the world.

In situ gold adsorption experiment at an acidic hot spring using a blue-green algal sheet

Gold (Au), as one of the most precious metal resources that is used for both industrial products and private ornaments, is a global investment target, and mining companies are making huge investments to discover new Au deposits. Here, we report in situ Au adsorption in an acidic hot spring by a unique adsorption sheet made from blue-green algae with a high preferential adsorption ability for Au. The results of in situ Au adsorption experiments conducted for various reaction times ranging from 0.2 h to 7 months showed that a maximum Au concentration of 30 ppm was adsorbed onto the blue-green algal sheet after a reaction time of 7 months. The Au concentration in the hot spring water was below the detection limit (< 1 ppt); therefore, Au was enriched by preferential adsorption onto the blue-green algal sheet by a factor of more than ~ 3 × 107. Thus, our gold recovery method has a high potential to recover Au even from an Au-poor solution such as hot spring water or mine wastewater with a low impact on the environment.