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1.
Chemosphere ; 287(Pt 3): 132323, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34563776

RESUMEN

This study investigated the concentration of radon (222Rn) in hot springs water. For this purpose, 222Rn concentration was measured using the RAD7 (Durridge Company, USA) in the water of hot springs located in Tata Pani, Gilgit (n = 4), and Garam Chashma, Chitral (n = 6), northern Pakistan. Water samples from the springs (background, n = 3) were also collected and analyzed for 222Rn concentration 40-50 km away from the hot springs in Gilgit and Chitral, northern Pakistan, to be used as background/reference concentration. The determined 222Rn in hot springs water surpassed the threshold of maximum contamination level (MCL, 11.1 Bq/L) set by the United States Environmental Protection Agency (US-EPA) in 100% samples collected from Tata Pani, Gilgit, and Garam Chashma, Chitral sites. Soil 222Rn along with the hot springs exhibited a decreasing trend with increasing distance. 222Rn concentration in hot springs water was used to calculate the exposure doses of human health through ingestion and inhalation pathways. The total effective dose for human (EWT) of 222Rn contaminated water consumption was 626 µSv/a in the Tata Pani, Gilgit and 34.7 µSv/a in the Garam Chashma, Chitral. Results revealed that hot springs water in the Tata Pani, Gilgit had surpassed the threshold limit (100 µSv/a) set by the World Health Organization (WHO). This study concluded that hot springs water should be avoided for drinking and other domestic uses.


Asunto(s)
Agua Potable , Manantiales de Aguas Termales , Monitoreo de Radiación , Radón , Contaminantes Radiactivos del Agua , Ingestión de Líquidos , Agua Potable/análisis , Humanos , Pakistán , Radón/análisis , Estados Unidos , Contaminantes Radiactivos del Agua/análisis
2.
Inquiry ; 58: 469580211049063, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34649472

RESUMEN

Background: Balneotherapy and hydrotherapy offer interesting treatment alternatives and are commonly used as additional interventions in the management of musculoskeletal disorders and pain management. Therefore, the aim of this study was to assess the effect of balneotherapy on musculoskeletal disorder pain and its perceived improvement among users of hot spring water in Southern Ethiopia. Methods: A single-arm cohort study and convenient sampling method were used to select 1337 study participants from four hot springs in Southern Ethiopia. A structured questionnaire, a physical examination, and laboratory blood tests were used to collect data. Data were entered using Epi data and transferred to SPSS 25 for cleaning and analysis. Descriptive analysis was made. Results: A total of 1279 participants were included in the study, giving a response rate of 96%. The majority of these patients have multiple health problems. Of all, 1137 (88.9%) of the patients were visiting the hot springs for joint pain followed by muscle pain 669 (52.2). Out of all cases of joint pain, 132 (11.6%) were clinically diagnosed with rheumatoid arthritis, and 5.3% were confirmed as having the disease based on a laboratory test. Of the total number of study participants, 1064 (83.2%) reported complete relief from the complaints they had at the start of the bath. Conclusions: Hot spring baths for three and more days have significant therapeutic effects on patients with musculoskeletal disorders, including rheumatoid arthritis. Physicians who are currently working in the area of diagnosis and treatment of patients in government and public facilities of the southern region should consider hot spring bath treatment for those patients with complaints of musculoskeletal pain, nonspecific arthritis, and rheumatoid arthritis. A hot spring bath is beneficial for everyone because it is a natural treatment with few side effects and a low cost.


Asunto(s)
Balneología , Manantiales de Aguas Termales , Dolor Musculoesquelético , Estudios de Cohortes , Etiopía , Humanos , Dolor Musculoesquelético/terapia , Manejo del Dolor , Agua
3.
Int J Syst Evol Microbiol ; 71(10)2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34596507

RESUMEN

Twelve thermophilic Anoxybacillus strains were isolated from sediment and water samples from a Karvachar hot spring located in the northern part of Nagorno-Karabakh. Based on phenotypic, chemotaxonomic and phylogenetic characteristics, one of the isolates, designated strain K1T, was studied in detail. The cells are straight, motile rods that are 0.2-0.4×2.3-7.2 µm in size. The strain is a Gram-stain-positive, moderately thermophilic facultative anaerobe with an optimum growth temperature of 60-65 °C and a growth temperature range of 45-70 °C. Growth of strain K1T was observed at pH 6-11 (optimum, pH 8-9) and was inhibited in the presence of NaCl concentrations above 2.5 % (optimum, 1-1.5 %). The isolate could utilize a wide variety of carbon sources, including d-arabinose, d-ribose, d-galactose, d-fructose, d-mannitol, maltose, aesculin, melibiose, sucrose, trehalose, raffinose, amidone, glycogen, turanose, d-lyxose, d-tagatose, potassium gluconate and 2-keto-gluconate. The strain was able to hydrolyse starch, casein and gelatin, was positive for oxidase and catalase, and reduced nitrate to nitrite, but was negative for H2S production. Production of urease and indole was not observed. The major cellular fatty acids were C15 : 0 iso, C16 : 0 and C17 : 0 iso (52.5, 13.6 and 19.6 % of total fatty acids, respectively). Strain K1T shares >99 % 16S rRNA sequence similarity and a genomic average nucleotide identity value of 94.5 % with its closest relative, Anoxybacillus flavithermus DSM 2641T, suggesting that it represents a separate and novel species, for which the name Anoxybacillus karvacharensis sp. nov. is proposed. The type strain of Anoxybacillus karvacharensis is K1T (=DSM 106524T=KCTC 15807T).


Asunto(s)
Anoxybacillus , Manantiales de Aguas Termales , Anoxybacillus/genética , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
4.
J Prev Med Hyg ; 62(2): E479-E488, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34604589

RESUMEN

Introduction: Balneotherapy centers of Ischia island (Italy) offer treatments for different dermatological diseases (psoriasis, acne, atopic dermatitis) and upper respiratory tract infections. In this study, we integrated morphological and molecular approaches to give a focus on isolation and screening of extremophile bacteria from Ischia thermal mud for potential antimicrobial applications. Methods: Samples were collected during 2019 at four sites. Some bacterial strains ATCC for antibacterial and antibiofilm activity were tested. After morphological characterization, screening for antagonistic isolates was made. The colonies isolated from thermal mud samples were submitted to molecular characterization. Susceptibility testing by dilution spotting was carried out and antibacterial efficacies of most active isolate were evaluated with a Minimal inhibition concentration assay. Biofilm formation, inhibition, eradication were examined. Statistical analyses were carried out utilizing Microsoft® Excel 2016/XLSTAT©-Pro. Results: We isolated a natural compound with antimicrobial and antibiofilm activities. Conclusions: The results obtained in this study are discussed in the context of how hydrothermal systems are important environmental source of uncharted antimicrobial and antibiofilm compounds. In conclusion, to the most effective of our knowledge, this work presents the primary report on the preliminary investigation of thermophile microbial diversity and their antimicrobial and antibiofilm activities for future biotechnological interest.


Asunto(s)
Antibacterianos , Bacterias/clasificación , Manantiales de Aguas Termales , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/aislamiento & purificación , Balneología , Manantiales de Aguas Termales/microbiología , Italia , Pruebas de Sensibilidad Microbiana
5.
Int J Syst Evol Microbiol ; 71(10)2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34672921

RESUMEN

Red-pigmented strains of non-sporeforming, aerobic, chemoorganotrophic bacteria were isolated from intertidal hot springs in Laugarvík, NW-Iceland. Cells stained Gram-negative and formed pleomorphic rods that often had swollen ends and occurred singly or in filaments. Growth was observed at 40-65 °C (optimum at 60 °C), pH 6-9 (optimum at 6.5-8) and 0.5-5% (optimum at 1-2%) (w/v) NaCl. Strain ISCAR-4553T contained MK-7 as the main respiratory quinone and saturated iso and anteiso branched chains of 17 and 15 carbons as the main cellular fatty acids (83.4%). The G+C content of the DNA is 67.3 mol%. The highest 16S rRNA gene sequence similarity was with the genus Roseithermus (92.0%) and followed by Rhodothermus, Rubrivirga and Rubricoccus (88-90%). Genome and phenotype comparisons supported the affiliation of the novel isolates and the genus Roseithermus to the family Rhodothermaceae of the phylum Rhodothermaeota. The described isolates are proposed to be classified as representatives of a novel species belonging to a novel genus, with the name Rhodocaloribacter litoris gen. nov., sp. nov. The type strain is ISCAR-4553T (=DSM 110790T = ATCC TSD-179T).


Asunto(s)
Manantiales de Aguas Termales , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
6.
Artículo en Inglés | MEDLINE | ID: mdl-34542397

RESUMEN

A novel nitrogen-fixing fermentative bacterium, designated as YA01T, was isolated from Nakabusa hot springs in Japan. The short-rod cells of strain YA01T were Gram-positive and non-sporulating. Phylogenetic trees of the 16S rRNA gene sequence and concatenated sequences of 40 single-copy ribosomal genes revealed that strain YA01T belonged to the genus Caldicellulosiruptor and was closely related to Caldicellulosiruptor hydrothermalis 108T, Caldicellulosiruptor bescii DSM 6725T and Caldicellulosiruptor kronotskyensis 2002T. The 16S rRNA gene sequence of strain YA01T shares less than 98.1 % identity to the known Caldicellulosiruptor species. The G+C content of the genomic DNA was 34.8 mol%. Strain YA01T shares low genome-wide average nucleotide identity (90.31-91.10 %), average amino acid identity (91.45-92.10 %) and <70 % digital DNA-DNA hybridization value (41.8-44.2 %) with the three related species of the genus Caldicellulosiruptor. Strain YA01T grew at 50-78 °C (optimum, 70 °C) and at pH 5.0-9.5 (optimum, pH 6.5). Strain YA01T mainly produced acetate by consuming d(+)-glucose as a carbon source. The main cellular fatty acids were iso-C17 : 0 (35.7 %), C16 : 0 (33.3 %), DMA16 : 0 (6.6 %) and iso-C15 : 0 (5.9 %). Based on its distinct phylogenetic position, biochemical and physiological characteristics, and the major cellular fatty acids, strain YA01T is considered to represent a novel species of the genus Caldicellulosiruptor for which the name Caldicellulosiruptor diazotrophicus sp. nov. is proposed (type strain YA01T=DSM 112098T=JCM 34253T).


Asunto(s)
Manantiales de Aguas Termales , Técnicas de Tipificación Bacteriana , Composición de Base , Caldicellulosiruptor , ADN Bacteriano/genética , Ácidos Grasos/química , Japón , Nitrógeno , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
7.
J Water Health ; 19(4): 563-574, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34371494

RESUMEN

The occurrence of potentially pathogenic free-living amoebae (FLA) in natural hot springs is considered a public health concern. FLAs are known to cause serious health outcomes to a wide spectrum of mammalian hosts. The present study aimed to provide the distribution of isolated cases of FLAs in hot springs through a systematic review process of available published articles online. Relevant studies are published between January 2010 and January 2020 involving the isolation of Naegleria spp., Acanthamoeba spp., Balamuthia spp., Sappinia spp., and Vermamoeba spp. in natural hot springs in the United States, South America, North America, Europe, Asia, and Africa. Articles were identified through a search of PubMed and Google Scholar databases. Out of 94 articles screened, a total of 20 articles are included in the study with consideration of established inclusion and exclusion criteria. The most common FLAs isolated in hot springs are Acanthamoeba spp. (134; 48.5%) and Naegleria spp. (127; 46.0%). Other FLAs isolated in hot springs include Balamuthia spp. (2; 0.7%) and Vermamoeba spp. (13; 4.7%). FLA in hot springs used for recreational and medical purposes is a potential source of infection. It is recommended that strict surveillance and maintenance of hot springs be implemented to prevent potential future infection.


Asunto(s)
Acanthamoeba , Amoeba , Manantiales de Aguas Termales , Naegleria , Animales , Humanos , Prevalencia
8.
Curr Microbiol ; 78(9): 3439-3452, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34258683

RESUMEN

Hot springs harbour diverse and interesting groups of microorganisms adapted to extreme conditions. However, due to limitations in the culture-dependent approach, most of such thermophiles remain uncultured and unexplored. Hence, this study was conducted to gain a comprehensive understanding of the bacterial diversity of Mahapelessa hot spring, Sri Lanka using both culture-dependent and culture-independent approaches. The in situ temperature of the water sample was 44.5 °C and the pH was 8.14. 16S rRNA Sanger sequencing of DNA extracted from the 18 bacterial isolates revealed the presence of eight genera belonging to two phyla: Proteobacteria (84%) and Firmicutes (16%) and the most abundant genus being Klebsiella. A total of 23 bacterial phyla representing 80 classes, 43 orders, 123 families, 205 genera and 83 species were detected by 16S rRNA V3-V4 region by amplicon metagenome sequencing of DNA extracted from water samples, where the most abundant phylum was the Proteobacteria (57.39%), followed by Firmicutes (23.7%) and Chloroflexi (4.14%). The three phyla Actinobacteria, Planctomycetes and Bacteroidetes were also detected less than 3% in abundance while 4.48% of bacteria could not be fit into any known phylum. The most abundant genera were Burkholderia (14.87%), Desulfotomaculum (7.23%) and Stenotrophomonas (6.1%). Four strictly anaerobic bacteria, Anaerosolibacter carboniphilus (0.71%), Bellilinea caldifistulae (0.04%), Salimesophilobacter vulgaris (0.1%), Anaerobacterium chartisolvens (0.12%); two potential plant growth-promoting bacteria, Azospirillum halopraeferens (0.04%) and Bradyrhizobium liaoningense (0.16%) and one potential alkali tolerant and sulphate-reducing bacterium, Desulfovibrio alkalitolerans (0.45%) were recorded. Pigmentiphaga sp. was isolated from Mahapelessa hot spring and to the best of our knowledge, this is the first record of this genus from a hot spring. This study gives insight into the vast bacterial diversity present in the Mahapelessa hot spring from the culture-independent approach which could not be identified using standard culturing techniques.


Asunto(s)
Manantiales de Aguas Termales , Azospirillum , Bacterias/genética , Bradyrhizobium , Chloroflexi , Clostridiaceae , Clostridiales , Desulfovibrionaceae , Humanos , Filogenia , ARN Ribosómico 16S/genética
9.
Biomed Res Int ; 2021: 1869748, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34258259

RESUMEN

Anoxybacillus kamchatkensis NASTPD13 isolated from Paudwar hot spring of Myagdi, Nepal, upon morphological and biochemical analysis revealed to be Gram-positive, straight or slightly curved, rod-shaped, spore-forming, catalase, and oxidase-positive facultative anaerobes. It grows over a wide range of pH (5.0-11) and temperature (37-75°C), which showed growth in different reduced carbon sources such as starch raffinose, glucose, fructose, inositol, trehalose, sorbitol, mellobiose, and mannitol in aerobic conditions. Furthermore, the partial sequence obtained upon sequencing showed 99% sequence similarity in 16S rRNA gene sequence with A. kamchatkensis JW/VK-KG4 and was suggested to be Anoxybacillus kamchatkensis. Moreover, whole-genome analysis of NASTPD13 revealed 2,866,796 bp genome with a G+C content of 41.6%. Analysis of the genome revealed the presence of 102 RNA genes, which includes sequences coding for 19 rRNA and 79 tRNA genes. While the 16S rRNA gene sequence of strain NASTPD13 showed high similarity (>99%) to those of A. kamchatkensis JW/VK-KG4, RAST analysis of NASTPD13 genome suggested that A. kamchatkensis G10 is actually the closest neighbor in terms of sequence similarity. The genome annotation by RAST revealed various genes encoding glycoside hydrolases supporting that it can utilize several reduced carbon sources as observed and these genes could be important for carbohydrate-related industries. Xylanase pathway, particularly the genomic region encoding key enzymes for xylan depolymerization and xylose metabolism, further confirmed the presence of the complete gene in xylan metabolism. In addition, the complete xylose utilization gene locus analysis of NASTPD13 genome revealed all including D-xylose transport ATP-binding protein XylG and XylF, the xylose isomerase encoding gene XylA, and the gene XylB coding for a xylulokinase supported the fact that the isolate contains a complete set of genes related to xylan degradation, pentose transport, and metabolism. The results of the present study suggest that the isolated A. kamchatkensis NASTPD13 containing xylanase-producing genes could be useful in lignocellulosic biomass-utilizing industries where pentose polymers could also be utilized along with the hexose polymers.


Asunto(s)
Anoxybacillus/genética , Análisis de Datos , Manantiales de Aguas Termales/microbiología , Secuenciación Completa del Genoma , Secuencia de Aminoácidos , Anoxybacillus/enzimología , Anoxybacillus/ultraestructura , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , ADN Circular/genética , Genoma Bacteriano , Glicósido Hidrolasas/metabolismo , Anotación de Secuencia Molecular , Nepal , Sistemas de Lectura Abierta/genética , Filogenia , Xilosa/metabolismo
10.
Syst Appl Microbiol ; 44(4): 126230, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34293647

RESUMEN

A novel hyperthermophilic crenarchaeon, strain 3507LTT, was isolated from a terrestrial hot spring near Tinguiririca volcano, Chile. Cells were non-motile thin, slightly curved filamentous rods. It grew at 73-93 °C and pH range of 5 to 7.5 with an optimum at 85 °C and pH 6.0-6.7. The presence of culture broth filtrate of another hyperthemophilic archaeon as well as yeast extract was obligatory for growth of the novel isolate. Strain 3507LTT is an anaerobic chemoorganoheterotroph, fermenting monosaccharides, disaccharides and polysaccharides (lichenan, starch, xanthan gum, xyloglucan, alpha-cellulose and amorphous cellulose). No growth stimulation was detected when nitrate, thiosulfate, selenate or elemental sulfur were added as the electron acceptors. The complete genome of strain 3507LTT consisted of a single circular chromosome with size of 1.63 Mbp. The DNA G+C content was 53.9%. According to the 16S rRNA gene sequence as well as conserved protein sequences phylogenetic analyses, strain 3507LTT together with Thermofilum uzonense formed a separate cluster within a Thermofilaceae family (Thermoproteales/Thermoprotei/Crenarchaeota). Based on phenotypic characteristics, phylogeny as well as AAI comparisons, a novel genus and species Infirmifilum lucidum strain 3507LTT (=VKM B-3376T = KCTC 15797T) gen. nov. sp. nov. was proposed. Its closest relative, Thermofilum uzonense strain 1807-2T should be reclassified as Infirmifilum uzonense strain 1807-2T comb. nov. Finally, based on phylogenomic and comparative genome analyses of representatives of Thermofilaceae family and other representatives of Thermoproteales order, a proposal of transfer of the family Thermofilaceae into a separate order Thermofilales ord. nov. was made.


Asunto(s)
Manantiales de Aguas Termales/microbiología , Filogenia , Thermofilaceae , Técnicas de Tipificación Bacteriana , Composición de Base , Chile , ADN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Thermofilaceae/clasificación , Thermofilaceae/aislamiento & purificación
11.
Environ Microbiol ; 23(7): 4034-4053, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34111905

RESUMEN

Hot springs integrate hydrologic and geologic processes that vary over short- and long-term time scales. However, the influence of temporal hydrologic and geologic change on hot spring biodiversity is unknown. Here, we coordinated near-weekly, cross-seasonal (~140 days) geochemical and microbial community analyses of three widely studied hot springs with local precipitation data in Yellowstone National Park. One spring ('HFS') exhibited statistically significant, coupled microbial and geochemical variation across seasons that was associated with recent precipitation patterns. Two other spring communities, 'CP' and 'DS', exhibited minimal to no variation across seasons. Variability in the seasonal response of springs is attributed to differences in the timing and extent of aquifer recharge with oxidized near-surface water from precipitation. This influx of oxidized water is associated with changes in community composition, and in particular, the abundances of aerobic sulfide-/sulfur-oxidizers that can acidify waters. During sampling, a new spring formed after a period of heavy precipitation and its successional dynamics were also influenced by surface water recharge. Collectively, these results indicate that changes in short-term hydrology associated with precipitation can impact hot spring geochemistry and microbial biodiversity. These results point to potential susceptibility of certain hot springs and their biodiversity to sustained, longer-term hydrologic changes.


Asunto(s)
Manantiales de Aguas Termales , Biodiversidad , Geología , Hidrología , ARN Ribosómico 16S , Estaciones del Año
12.
Int J Biol Macromol ; 185: 277-286, 2021 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-34147526

RESUMEN

Members of group Bacillus are most widely occurring microbes in agricultural soil and they affect crop health in various ways. They directly stimulate plant growth either by augmenting nutrients availability, invigorating plants' defence mechanisms; repressing soil-borne phytopathogens or by producing growth-regulating hormones like auxins and cytokinins. It is a well known fact that indole-3- acetic acid (a type of auxin) is a vital biologically active phytohormone excreted by certain Bacillus species, but its molecular mechanism has not yet been described. In this study, the auxin efflux carrier gene is isolated from the metagenome of the Tapta Kund hot spring, Uttrakhand, India. In addition, auxin efflux carrier (AEC) transporter protein of Bacillus licheniformis is modeled and the 318 amino acid residues long protein was found homologous to the apical sodium-dependent bile acid transporter (ASBT) of Yersinia frederiksnii, with 10 transmembrane segments (TM1-10) split into different domains: a panel domain defined by TM1, 2, 6 and 7; and a core domain defined by TM3-5 and 8-10. Finally, the predicted Bacillus licheniformis AEC protein has also been phylogenetically evaluated and its detailed molecular transport mechanism was worked out using molecular dynamics simulation analysis. Conclusively, this study demonstrates the efflux mechanism of the substrate, Indole 3- acetic acid by AEC transporter protein.


Asunto(s)
Bacillus licheniformis/aislamiento & purificación , Manantiales de Aguas Termales/microbiología , Ácidos Indolacéticos/metabolismo , Proteínas de Transporte de Membrana/química , Proteínas de Transporte de Membrana/genética , Secuencia de Aminoácidos , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Transporte Biológico , India , Proteínas de Transporte de Membrana/metabolismo , Metagenómica , Modelos Moleculares , Simulación de Dinámica Molecular , Dominios Proteicos , Estructura Terciaria de Proteína
13.
Eur J Protistol ; 80: 125812, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34139569

RESUMEN

Several thermal areas, also used for leisure purposes, may represent suitable habitats for free-living amoebae (FLAs), but few studies have been carried out in search for these organisms. The aim of this study was to assess the presence and distribution of FLAs by culture detection and molecular identification, over a one year-round sampling of two sites in Central Italy. Two geothermal springs (Site A and Site B) were investigated for a total of 36 water samples. Four sets of primers were used to amplify FLA DNA from all cultures positive for amoebic growth at both 37 °C and 45 °C. Overall, 33 (91.6%) water samples produced PCR amplification. Eleven taxa were identified. The array of identified species varied over the sampling period, and differed between the two hot springs, Site A harbouring 11 taxa compared to 5 of site B. However, both sites were characterized by the most common species Vermamoeba vermiformis and Naegleria australiensis. Acanthamoeba genotypes T4 and T15 were found at low frequency. Differences in the composition between the two sites could reflect environmental changes in biotic and chemical/physical parameters. From a public health perspective, the detection of potentially pathogenic amoebae could unveil a potential risk for humans.


Asunto(s)
Amoeba/clasificación , Manantiales de Aguas Termales/parasitología , Amoeba/genética , ADN Protozoario/genética , Genotipo , Italia , Reacción en Cadena de la Polimerasa , Especificidad de la Especie , Termotolerancia
14.
Arch Microbiol ; 203(7): 3751-3766, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34143270

RESUMEN

The term extremophile was suggested more than 30 years ago and represents microorganisms that are capable of developing and living under extreme conditions, these conditions being particularly hostile to other types of microorganisms and to humankind. In terrestrial hydrothermal sites, like hot springs, "mud pools", solfataras, and geysers, the dominant extreme conditions are high temperature, low or high pH, and high levels of salinity. The diversity of microorganisms inhabiting these sites is determined by the conditions of the environment. Organisms belonging to the domains Archaea and Bacteria are more represented than the one belonging to Eukarya. Eukarya members tend to be less present because of their lower tolerance to higher temperatures, however, they perform important ecosystem processes when present. Both prokaryotes and eukaryotes have morphological and physical adaptations that allow them to colonize extreme environments. Microbial mats are complex associations of microorganisms that help the colonization of more extreme systems. In this review, a characterization of prokaryotic and eukaryotic organisms that populate terrestrial hydrothermal systems are made.


Asunto(s)
Archaea , Bacterias , Biodiversidad , Eucariontes , Manantiales de Aguas Termales , Archaea/clasificación , Archaea/genética , Bacterias/clasificación , Bacterias/genética , Eucariontes/clasificación , Eucariontes/genética
15.
Microbiome ; 9(1): 135, 2021 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-34116726

RESUMEN

BACKGROUND: Terrestrial hot spring settings span a broad spectrum of physicochemistries. Physicochemical parameters, such as pH and temperature, are key factors influencing differences in microbial composition across diverse geothermal areas. Nonetheless, analysis of hot spring pools from the Taupo Volcanic Zone (TVZ), New Zealand, revealed that some members of the bacterial genus, Acidithiobacillus, are prevalent across wide ranges of hot spring pHs and temperatures. To determine the genomic attributes of Acidithiobacillus that inhabit such diverse conditions, we assembled the genomes of 19 uncultivated hot spring Acidithiobacillus strains from six geothermal areas and compared these to 37 publicly available Acidithiobacillus genomes from various habitats. RESULTS: Analysis of 16S rRNA gene amplicons from 138 samples revealed that Acidithiobacillus comprised on average 11.4 ± 16.8% of hot spring prokaryotic communities, with three Acidithiobacillus amplicon sequence variants (ASVs) (TVZ_G1, TVZ_G2, TVZ_G3) accounting for > 90% of Acidithiobacillus in terms of relative abundance, and occurring in 126 out of 138 samples across wide ranges of temperature (17.5-92.9 °C) and pH (1.0-7.5). We recovered 19 environmental genomes belonging to each of these three ASVs, as well as a fourth related group (TVZ_G4). Based on genome average nucleotide identities, the four groups (TVZ_G1-TVZ_G4) constitute distinct species (ANI < 96.5%) of which three are novel Acidithiobacillus species (TVZ_G2-TVZ_G4) and one belongs to Acidithiobacillus caldus (TVZ_G1). All four TVZ Acidithiobacillus groups were found in hot springs with temperatures above the previously known limit for the genus (up to 40 °C higher), likely due to significantly higher proline and GC contents than other Acidithiobacillus species, which are known to increase thermostability. Results also indicate hot spring-associated Acidithiobacillus have undergone genome streamlining, likely due to thermal adaptation. Moreover, our data suggest that Acidithiobacillus prevalence across varied hot spring pHs is supported by distinct strategies, whereby TVZ_G2-TVZ_G4 regulate pH homeostasis mostly through Na+/H+ antiporters and proton-efflux ATPases, whereas TVZ_G1 mainly relies on amino acid decarboxylases. CONCLUSIONS: This study provides insights into the distribution of Acidithiobacillus species across diverse hot spring physichochemistries and determines genomic features and adaptations that potentially enable Acidithiobacillus species to colonize a broad range of temperatures and pHs in geothermal environments. Video Abstract.


Asunto(s)
Acidithiobacillus , Manantiales de Aguas Termales , Acidithiobacillus/genética , Metagenómica , Nueva Zelanda , ARN Ribosómico 16S/genética , Temperatura
16.
Microbes Environ ; 36(2)2021.
Artículo en Inglés | MEDLINE | ID: mdl-34108360

RESUMEN

Fermentative nitrogen-fixing bacteria have not yet been examined in detail in thermal environments. In the present study, we isolated the thermophilic fermentative bacterium, strain YA01 from a hot spring. This strain grew at temperatures up to 78°C. A phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain YA01 belonged to the genus Caldicellulosiruptor, which are fermentative bacteria in the phylum Firmicutes, with 97.7-98.0% sequence identity to its closest relatives. Strain YA01 clearly exhibited N2-dependent growth at 70°C. We also confirmed N2-dependent growth in the relatives of strain YA01, Caldicellulosiruptor hydrothermalis 108 and Caldicellulosiruptor kronotskyensis 2002. The nitrogenase activities of these three strains were examined using the acetylene reduction assay. Similar activities were detected for all tested strains, and were slightly suppressed by the addition of ammonium. A genome analysis revealed that strain YA01, as well as other Caldicellulosiruptor, possessed a gene set for nitrogen fixation, but lacked the nifN gene, which encodes a nitrogenase iron-molybdenum cofactor biosynthesis protein that is commonly detected in nitrogen-fixing bacteria. The amino acid sequences of nitrogenase encoded by nifH, nifD, and nifK shared 92-98% similarity in Caldicellulosiruptor. A phylogenetic tree of concatenated NifHDK sequences showed that NifHDK of Caldicellulosiruptor was in the deepest clade. To the best of our knowledge, this is the first study to demonstrate the nitrogen-fixing ability of fermentative bacteria at 70°C. Caldicellulosiruptor may have retained an ancient nitrogen-fixing enzyme system.


Asunto(s)
Caldicellulosiruptor/aislamiento & purificación , Caldicellulosiruptor/fisiología , Fijación del Nitrógeno , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Caldicellulosiruptor/clasificación , Caldicellulosiruptor/genética , Fermentación , Genoma Bacteriano , Manantiales de Aguas Termales/química , Manantiales de Aguas Termales/microbiología , Calor , Nitrógeno/metabolismo , Nitrogenasa/química , Nitrogenasa/genética , Nitrogenasa/metabolismo , Filogenia
17.
Artículo en Inglés | MEDLINE | ID: mdl-34003738

RESUMEN

A novel anaerobic, alkaliphilic, mesophilic, Gram-stain-positive, endospore-forming bacterium was isolated from an alkaline thermal spring (42 °C, pH 9.0) in New Caledonia. This bacterium, designated strain LB2T, grew at 25-50 °C (optimum, 37 °C) and pH 8.2-10.8 (optimum, pH 9.5). Added NaCl was not required for growth (optimum, 0-1 %) but was tolerated up to 7 %. Strain LB2T utilized a limited range of substrates, such as peptone, pyruvate, yeast extract and xylose. End products detected from pyruvate fermentation were acetate and formate. Both ferric citrate and thiosulfate were used as electron acceptors. Elemental sulphur, nitrate, nitrite, fumarate, sulphate, sulfite and DMSO were not used as terminal electron acceptors. The two major cellular fatty acids were iso-C15 : 0 and C16 : 0. The genome consists of a circular chromosome (3.7 Mb) containing 3626 predicted protein-encoding genes with a G+C content of 36.2 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the isolate is a member of the family Proteinivoraceae, order Clostridiales within the phylum Firmicutes. Strain LB2T was most closely related to the thermophilic Anaerobranca gottschalkii LBS3T (93.2 % 16S rRNA gene sequence identity). Genome-based analysis of average nucleotide identity and digital DNA-DNA hybridization of strain LB2T with A. gottschalkii LBS3T showed respective values of 70.8 and 13.4 %. Based on phylogenetic, genomic, chemotaxonomic and physiological properties, strain LB2T is proposed to represent the first species of a novel genus, for which the name Alkalicella caledoniensis gen. nov., sp. nov. is proposed (type strain LB2T=DSM 100588T=JCM 30958T).


Asunto(s)
Clostridiales/clasificación , Manantiales de Aguas Termales/microbiología , Filogenia , Anaerobiosis , Bacterias Anaerobias/clasificación , Bacterias Anaerobias/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , Clostridiales/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Fermentación , Nueva Caledonia , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
18.
Microbes Environ ; 36(2)2021.
Artículo en Inglés | MEDLINE | ID: mdl-33952861

RESUMEN

Cyanobacteria thrive in diverse environments. However, questions remain about possible growth limitations in ancient environmental conditions. As a single genus, the Thermosynechococcus are cosmopolitan and live in chemically diverse habitats. To understand the genetic basis for this, we compared the protein coding component of Thermosynechococcus genomes. Supplementing the known genetic diversity of Thermosynechococcus, we report draft metagenome-assembled genomes of two Thermosynechococcus recovered from ferrous carbonate hot springs in Japan. We find that as a genus, Thermosynechococcus is genomically conserved, having a small pan-genome with few accessory genes per individual strain as well as few genes that are unique to the genus. Furthermore, by comparing orthologous protein groups, including an analysis of genes encoding proteins with an iron related function (uptake, storage or utilization), no clear differences in genetic content, or adaptive mechanisms could be detected between genus members, despite the range of environments they inhabit. Overall, our results highlight a seemingly innate ability for Thermosynechococcus to inhabit diverse habitats without having undergone substantial genomic adaptation to accommodate this. The finding of Thermosynechococcus in both hot and high iron environments without adaptation recognizable from the perspective of the proteome has implications for understanding the basis of thermophily within this clade, and also for understanding the possible genetic basis for high iron tolerance in cyanobacteria on early Earth. The conserved core genome may be indicative of an allopatric lifestyle-or reduced genetic complexity of hot spring habitats relative to other environments.


Asunto(s)
Genoma Bacteriano , Thermosynechococcus/genética , Thermosynechococcus/aislamiento & purificación , Adaptación Fisiológica , Ecosistema , Genómica , Manantiales de Aguas Termales/microbiología , Japón , Filogenia , Thermosynechococcus/clasificación , Thermosynechococcus/fisiología
19.
Curr Microbiol ; 78(8): 2926-2934, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34047830

RESUMEN

Diversity of the microbial community in the Zharkent geothermal hot spring, located in the southeastern region of Kazakhstan, was assessed using both culture-dependent and -independent approaches. Shotgun metagenomic sequencing of DNA extracted from the spring water yielded 11,061,725 high-quality sequence reads, totaling >1,67 Gb of nucleotide sequences. Furthermore, water samples were enriched in nutrient broth at varying high temperatures, and colonies isolated by being streaked onto nutrient agar. Finally, DNA extraction and amplification, as well as sequencing and phylogenetic analysis, were conducted. Bacteria constituted more than 99.97% of the total prokaryotic abundance, with Archaea contributing only an extremely small component; Firmicutes, Proteobacteria, and Actinobacteria dominated the community. At genus level, Firmicutes reads affiliated with Desmospora, Parageobacillus, Paenibacillus, and Brevibacillus, accounting for more than 60% of total prokaryotic abundance. Eight morphologically distinct, aerobic, endospore-forming thermophilic bacteria were recovered; isolates differed significantly in substrate utilization patterns, as well as their production of thermophilic, extracellular, hydrolytic enzymes for degradation of starch, lipids, cellulose, and protein. Five strains could degrade all four macromolecular types at temperatures ranging from 55 to 75 °C. Phylogenetic analyses based on 16S rRNA gene sequences placed all isolates into the genus Geobacillus with some of them possibly representing novel species. The results indicate that this hot spring represents a rich source of novel thermophilic bacteria and potentially useful thermostable enzymes.


Asunto(s)
Manantiales de Aguas Termales , Archaea/genética , ADN Bacteriano/genética , Kazajstán , Metagenómica , Filogenia , ARN Ribosómico 16S/genética
20.
Int J Mol Sci ; 22(6)2021 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-33799806

RESUMEN

Carbonic anhydrases (CAs) have been identified as ideal catalysts for CO2 sequestration. Here, we report the sequence and structural analyses as well as the molecular dynamics (MD) simulations of four γ-CAs from thermophilic bacteria. Three of these, Persephonella marina, Persephonella hydrogeniphila, and Thermosulfidibacter takaii originate from hydrothermal vents and one, Thermus thermophilus HB8, from hot springs. Protein sequences were retrieved and aligned with previously characterized γ-CAs, revealing differences in the catalytic pocket residues. Further analysis of the structures following homology modeling revealed a hydrophobic patch in the catalytic pocket, presumed important for CO2 binding. Monitoring of proton shuttling residue His69 (P. marina γ-CA numbering) during MD simulations of P. hydrogeniphila and P. marina's γ-CAs (γ-PhCA and γ-PmCA), showed a different behavior to that observed in the γ-CA of Escherichia coli, which periodically coordinates Zn2+. This work also involved the search for hotspot residues that contribute to interface stability. Some of these residues were further identified as key in protein communication via betweenness centrality metric of dynamic residue network analysis. T. takaii's γ-CA showed marginally lower thermostability compared to the other three γ-CA proteins with an increase in conformations visited at high temperatures being observed. Hydrogen bond analysis revealed important interactions, some unique and others common in all γ-CAs, which contribute to interface formation and thermostability. The seemingly thermostable γ-CA from T. thermophilus strangely showed increased unsynchronized residue motions at 423 K. γ-PhCA and γ-PmCA were, however, preliminarily considered suitable as prospective thermostable CO2 sequestration agents.


Asunto(s)
Proteínas Bacterianas/metabolismo , Biomineralización , Dióxido de Carbono/metabolismo , Anhidrasas Carbónicas/metabolismo , Secuencia de Aminoácidos , Bacterias/enzimología , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Dióxido de Carbono/química , Anhidrasas Carbónicas/química , Anhidrasas Carbónicas/genética , Catálisis , Dominio Catalítico , Simulación por Computador , Manantiales de Aguas Termales/microbiología , Respiraderos Hidrotermales/microbiología , Simulación de Dinámica Molecular , Conformación Proteica , Homología de Secuencia de Aminoácido , Temperatura , Thermus thermophilus/enzimología
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