Bacterial diversity and sulfur cycling in a mesophilic sulfide-rich spring. (1/272)

An artesian sulfide- and sulfur-rich spring in southwestern Oklahoma is shown to sustain an extremely rich and diverse microbial community. Laboratory incubations and autoradiography studies indicated that active sulfur cycling is occurring in the abundant microbial mats at Zodletone spring. Anoxygenic phototrophic bacteria oxidize sulfide to sulfate, which is reduced by sulfate-reducing bacterial populations. The microbial community at Zodletone spring was analyzed by cloning and sequencing 16S rRNA genes. A large fraction (83%) of the microbial mat clones belong to sulfur- and sulfate-reducing lineages within delta-Proteobacteria, purple sulfur gamma-Proteobacteria, epsilon -Proteobacteria, Chloroflexi, and filamentous Cyanobacteria of the order Oscillatoria as well as a novel group within gamma-Proteobacteria. The 16S clone library constructed from hydrocarbon-exposed sediments at the source of the spring had a higher diversity than the mat clone library (Shannon-Weiner index of 3.84 compared to 2.95 for the mat), with a higher percentage of clones belonging to nonphototrophic lineages (e.g., Cytophaga, Spirochaetes, Planctomycetes, Firmicutes, and Verrucomicrobiae). Many of these clones were closely related to clones retrieved from hydrocarbon-contaminated environments and anaerobic hydrocarbon-degrading enrichments. In addition, 18 of the source clones did not cluster with any of the previously described microbial divisions. These 18 clones, together with previously published or database-deposited related sequences retrieved from a wide variety of environments, could be clustered into at least four novel candidate divisions. The sulfate-reducing community at Zodletone spring was characterized by cloning and sequencing a 1.9-kb fragment of the dissimilatory sulfite reductase (DSR) gene. DSR clones belonged to the Desulfococcus-Desulfosarcina-Desulfonema group, Desulfobacter group, and Desulfovibrio group as well as to a deeply branched group in the DSR tree with no representatives from cultures. Overall, this work expands the division-level diversity of the bacterial domain and highlights the complexity of microbial communities involved in sulfur cycling in mesophilic microbial mats.  (+info)

Sulfurihydrogenibium azorense, sp. nov., a thermophilic hydrogen-oxidizing microaerophile from terrestrial hot springs in the Azores. (2/272)

Five hydrogen-oxidizing, thermophilic, strictly chemolithoautotrophic, microaerophilic strains, with similar (99-100%) 16S rRNA gene sequences were isolated from terrestrial hot springs at Furnas, Sao Miguel Island, Azores, Portugal. The strain, designated Az-Fu1T, was characterized. The motile, 0.9-2.0 microm rods were Gram-negative and non-sporulating. The temperature growth range was from 50 to 73 degrees C (optimum at 68 degrees C). The strains grew fastest in 0.1% (w/v) NaCl and at pH 6, although growth was observed from pH 5.5 to 7.0. Az-Fu1T can use elemental sulfur, sulfite, thiosulfate, ferrous iron or hydrogen as electron donors, and oxygen (0.2-9.0%, v/v) as electron acceptor. Az-Fu1T is also able to grow anaerobically, with elemental sulfur, arsenate and ferric iron as electron acceptors. The Az-Fu1T G+C content was 33.6 mol%. Maximum-likelihood analysis of the 16S rRNA phylogeny placed the isolate in a distinct lineage within the Aquificales, closely related to Sulfurihydrogenibium subterraneum (2.0% distant). The 16S rRNA gene of Az-Fu1T is 7.7% different from that of Persephonella marina and 6.8% different from Hydrogenothermus marinus. Based on the phenotypic and phylogenetic characteristics presented here, it is proposed that Az-Fu1T belongs to the recently described genus Sulfurihydrogenibium. It is further proposed that Az-Fu1T represents a new species, Sulfurihydrogenibium azorense.  (+info)

Biochemical comparison between radon effects and thermal effects on humans in radon hot spring therapy. (3/272)

The radioactive and thermal effects of radon hot spring were biochemically compared under a sauna room or hot spring conditions with a similar chemical component, using the parameters that are closely involved in the clinic for radon therapy. The results showed that the radon and thermal therapy enhanced the antioxidation functions, such as the activities of superoxide dismutase (SOD) and catalase, which inhibit lipid peroxidation and total cholesterol produced in the body. Moreover the therapy enhanced concanavalin A (ConA)-induced mitogen response and increased the percentage of CD4 positive cells, which is the marker of helper T cells, and decreased the percentage of CD8 positive cells, which is the common marker of killer T cells and suppressor T cells, in the white blood cell differentiation antigen (CD8/CD4) assay. Furthermore, the therapy increased the levels of alpha atrial natriuretic polypeptide (alpha ANP), beta endorphin, adrenocorticotropic hormone (ACTH), insulin and glucose-6-phosphate dehydrogenase (G-6-PDH), and it decreased the vasopression level. The results were on the whole larger in the radon group than in the thermal group. The findings suggest that radon therapy contributes more to the prevention of life-style-related diseases related to peroxidation reactions and immune suppression than to thermal therapy. Moreover, these indicate what may be a part of the mechanism for the alleviation of hypertension, osteoarthritis (pain), and diabetes mellitus brought about more by radon therapy than by thermal therapy.  (+info)

Anoxybacillus voinovskiensis sp. nov., a moderately thermophilic bacterium from a hot spring in Kamchatka. (4/272)

A novel moderately thermophilic bacterium, strain TH13T, was isolated from a hot spring in Kamchatka. It was found to be a Gram-positive, facultative aerobe; the straight, non-motile rods grew at 30-64 degrees C (optimum 54 degrees C). The isolate was positive for catalase and oxidase tests and reduced nitrate to nitrite, but was negative for H2S production and growth in more than 3% NaCl (w/v). The isolate grew at pH 7-8, but not at pH values higher than 9. The DNA G+C content was 43.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain TH13T was a member of the genus Anoxybacillus. DNA-DNA hybridization revealed a low relatedness (less than 30.2%) between the isolate and its close phylogenetic neighbours Anoxybacillus pushchinoensis and Anoxybacillus flavithermus. On the basis of phenotypic characteristics, phylogenetic data and DNA-DNA hybridization data, it was concluded that the isolate merited classification as a novel species, for which the name Anoxybacillus voinovskiensis sp. nov. is proposed. The type strain of this species is TH13T (=NCIMB 13956T=JCM 12111T).  (+info)

Nonmarine crenarchaeol in Nevada hot springs. (5/272)

Glycerol dialkyl glycerol tetraethers (GDGTs) are core membrane lipids of the Crenarchaeota. The structurally unusual GDGT crenarchaeol has been proposed as a taxonomically specific biomarker for the marine planktonic group I archaea. It is found ubiquitously in the marine water column and in sediments. In this work, samples of microbial community biomass were obtained from several alkaline and neutral-pH hot springs in Nevada, United States. Lipid extracts of these samples were analyzed by high-performance liquid chromatography-mass spectrometry and by gas chromatography-mass spectrometry. Each sample contained GDGTs, and among these compounds was crenarchaeol. The distribution of archaeal lipids in Nevada hot springs did not appear to correlate with temperature, as has been observed in the marine environment. Instead, a significant correlation with the concentration of bicarbonate was observed. Archaeal DNA was analyzed by denaturing gradient gel electrophoresis. All samples contained 16S rRNA gene sequences which were more strongly related to thermophilic crenarchaeota than to Cenarchaeum symbiosum, a marine nonthermophilic crenarchaeon. The occurrence of crenarchaeol in environments containing sequences affiliated with thermophilic crenarchaeota suggests a wide phenotypic distribution of this compound. The results also indicate that crenarchaeol can no longer be considered an exclusive biomarker for marine species.  (+info)

Anoxybacillus ayderensis sp. nov. and Anoxybacillus kestanbolensis sp. nov. (6/272)

Two thermophilic bacilli were isolated from mud and water samples of the Ayder and Kestanbol hot springs in the provinces of Rize and Canakkale, respectively, in Turkey. Strains AB04T and K4T were sporulating, Gram-positive, rod-shaped bacteria. These isolates were moderately thermophilic (with an optimum temperature for growth of 50-55 degrees C), facultative anaerobes able to grow on a wide range of carbon sources including d-glucose, d-raffinose, d-sucrose, D-xylose, D-fructose, L-arabinose, maltose, D-mannose and D-mannitol. Analysis of the 16S rRNA gene sequences showed that these isolates resembled Anoxybacillus flavithermus DSM 2641T and Anoxybacillus gonensis NCIMB 13933T. DNA-DNA hybridization data revealed that thermophilic isolate AB04T has only 51.2 % relatedness to A. flavithermus, 45.1 % relatedness to Anoxybacillus pushchinoensis and 68.6 % relatedness to A. gonensis. Thermophilic isolate K4T showed only 60.4 % relatedness to A. flavithermus, 42.9 % relatedness to A. pushchinoensis and 38.5 % relatedness to A. gonensis. On the basis of the DNA-DNA hybridization data, isolates AB04T and K4T are not related to A. flavithermus DSM 2641T, A. pushchinoensis DSM 12423T or A. gonensis NCIMB 13933T at the species level, but show relatedness to one another of 40.5 %. On the basis of the data presented, it is proposed that strains AB04T (= NCIMB 13972T = NCCB 100050T) and K4T (= NCIMB 13971T = NCCB 100051T) be designated as the type strains of Anoxybacillus ayderensis sp. nov. and Anoxybacillus kestanbolensis sp. nov., respectively.  (+info)

Alicyclobacillus vulcanalis sp. nov., a thermophilic, acidophilic bacterium isolated from Coso Hot Springs, California, USA. (7/272)

A thermo-acidophilic Gram-positive bacterium, strain CsHg2T, which grows aerobically at 35-65 degrees C (optimum 55 degrees C) and at pH 2.0-6.0 (optimum 4.0), was isolated from a geothermal pool located in Coso Hot Springs in the Mojave Desert, California, USA. Phylogenetic analysis of 16S rRNA gene sequences showed that this bacterium was most closely related to the type strains of Alicyclobacillus acidocaldarius (97.8 % identity) and Alicyclobacillus sendaiensis (96.9 %), three Japanese strains denoted as UZ-1, KHA-31 and MIH 332 (96.1-96.5 %) and Alicyclobacillus genomic species FR-6 (96.3 %). Phenotypic characteristics including temperature and pH optima, G+C composition, acid production from a variety of carbon sources and sensitivity to different metal salts distinguished CsHg2T from A. acidocaldarius, A. sendaiensis and FR-6. The cell lipid membrane was composed mainly of omega-cyclohexyl fatty acid, consistent with membranes from other Alicyclobacillus species. Very low DNA-DNA hybridization values between CsHg2T and the type strains of Alicyclobacillus indicate that CsHg2T represents a distinct species. On the basis of these results, the name Alicyclobacillus vulcanalis sp. nov. is proposed for this organism. The type strain is CsHg2T (ATCC BAA-915T = DSM 16176T).  (+info)

Rubrobacter taiwanensis sp. nov., a novel thermophilic, radiation-resistant species isolated from hot springs. (8/272)

Two novel bacteria, with an optimum growth temperature of approximately 60 degrees C, were isolated from Lu-shan hot springs in the central region of Taiwan. These isolates were aerobic, thermophilic, halotolerant, pink-pigmented, heterotrophic and resistant to gamma-radiation. Both pleomorphic, short, rod-shaped cells and coccoid cells were observed. Strains LS-286 (= ATCC BAA-452 = BCRC 17198) and LS-293T (= ATCC BAA-406T = BCRC 17173T) represented a novel species of the genus Rubrobacter, according to a phylogenetic analysis of the 16S rRNA gene, DNA-DNA hybridization, biochemical features and fatty acid composition. The name Rubrobacter taiwanensis sp. nov. is proposed for this novel species, with LS-293T as the type strain.  (+info)