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1.
Microbes Environ ; 34(3): 278-292, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31413226

RESUMO

Hydrothermal systems, including terrestrial hot springs, contain diverse geochemical conditions that vary over short spatial scales due to progressive interactions between reducing hydrothermal fluids, the oxygenated atmosphere, and, in some cases, seawater. At Jinata Onsen on Shikinejima Island, Japan, an intertidal, anoxic, iron-rich hot spring mixes with the oxygenated atmosphere and seawater over short spatial scales, creating diverse chemical potentials and redox pairs over a distance of ~10 m. We characterized geochemical conditions along the outflow of Jinata Onsen as well as the microbial communities present in biofilms, mats, and mineral crusts along its traverse using 16S rRNA gene amplicon and genome-resolved shotgun metagenomic sequencing. Microbial communities significantly changed downstream as temperatures and dissolved iron concentrations decreased and dissolved oxygen increased. Biomass was more limited near the spring source than downstream, and primary productivity appeared to be fueled by the oxidation of ferrous iron and molecular hydrogen by members of Zetaproteobacteria and Aquificae. The microbial community downstream was dominated by oxygenic Cyanobacteria. Cyanobacteria are abundant and active even at ferrous iron concentrations of ~150 µM, which challenges the idea that iron toxicity limited cyanobacterial expansion in Precambrian oceans. Several novel lineages of Bacteria are also present at Jinata Onsen, including previously uncharacterized members of the phyla Chloroflexi and Calditrichaeota, positioning Jinata Onsen as a valuable site for the future characterization of these clades.


Assuntos
Bactérias/metabolismo , Biodiversidade , Fontes Termais/química , Fontes Termais/microbiologia , Ferro/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biomassa , Crescimento Quimioautotrófico , Geografia , Ferro/análise , Metagenômica , Microbiota/genética , Oxigênio/análise , Oxigênio/metabolismo , Processos Fototróficos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Temperatura Ambiente
2.
Extremophiles ; 23(5): 599-612, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31376001

RESUMO

A novel thermophilic bacteriophage AP45 and its host strain Aeribacillus sp. CEMTC656 were isolated from the Valley of Geysers, Kamchatka Peninsula, Russia. Bacteriophage AP45 was identified as a member of the Siphoviridae family by electron microscopy. It showed high thermostability and had a slow cycle of reproduction. The AP45 genome had 51,606 base pairs (bp) and contained 71 open reading frames (ORFs), 40 of them encoding proteins of predicted function. Genes encoding DNA and RNA polymerases were not identified, indicating that AP45 used host polymerases. Based on the ORF65 encoding putative endolysin, the recombinant protein rAP45Lys was developed and its peptidoglycan-hydrolyzing activity was demonstrated. The AP45 genome exhibited limited identity to other phage sequences; the highest identity, 36%, was with the genome of the thermophilic Geobacillus myovirus D6E. The majority of putative proteins encoded by the AP45 genome had higher similarity to proteins from bacteria belonging to the Bacillaceae family, than to bacteriophages. In addition, more than half of the putative ORFs in the AP45 genome were highly similar to prophage sequences of A. pallidus strain 8m3, which was isolated in north-east China. The AP45 phage and revealed prophages might be members of a new genus belonging to the Siphoviridae family.


Assuntos
Bacillaceae/virologia , Genoma Viral , Siphoviridae/genética , Termotolerância , Fontes Termais/microbiologia , Fontes Termais/virologia , Fases de Leitura Aberta , Filogenia , Siphoviridae/classificação , Siphoviridae/patogenicidade
3.
Microbes Environ ; 34(3): 304-309, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31391357

RESUMO

Chloroflexus aggregans is a thermophilic filamentous anoxygenic phototrophic bacterium frequently found in microbial mats in natural hot springs. C. aggregans often thrives with cyanobacteria that engage in photosynthesis to provide it with an organic substrate; however, it sometimes appears as the dominant phototroph in microbial mats without cyanobacteria. This suggests that C. aggregans has the ability to grow photoautotrophically. However, photoautotrophic growth has not been observed in any cultured strains of C. aggregans. We herein attempted to isolate a photoautotrophic strain from C. aggregansdominated microbial mats in Nakabusa hot spring in Japan. Using an inorganic medium, we succeeded in isolating a new strain that we designated "ACA-12". A phylogenetic analysis based on 16S rRNA gene and 16S-23S rRNA gene internal transcribed spacer (ITS) region sequences revealed that strain ACA-12 was closely related to known C. aggregans strains. Strain ACA-12 showed sulfide consumption along with autotrophic growth under anaerobic light conditions. The deposited elemental sulfur particles observed by microscopy indicated that sulfide oxidation occurred, similar to that in photoautotrophic strains in the related species, C. aurantiacus. Moreover, we found that other strains of C. aggregans, including the type strain, also exhibited a slight photoautotrophic growing ability, whereas strain ACA-12 showed the fastest growth rate. This is the first demonstration of photoautotrophic growth with sulfide in C. aggregans. The present results strongly indicate that C. aggregans is associated with inorganic carbon incorporation using sulfide as an electron donor in hot spring microbial mats.


Assuntos
Chloroflexus/metabolismo , Processos Fototróficos , Sulfetos/metabolismo , Proteínas de Bactérias/genética , Chloroflexus/classificação , Chloroflexus/genética , Chloroflexus/efeitos da radiação , Meios de Cultura/química , DNA Bacteriano/genética , DNA Espaçador Ribossômico/genética , Fontes Termais/microbiologia , Japão , Luz , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sulfetos/análise , Enxofre/metabolismo
4.
BMC Res Notes ; 12(1): 444, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31331368

RESUMO

OBJECTIVE: Sulfodiicoccus acidiphilus HS-1T is the type species of the genus Sulfodiicoccus, a thermoacidophilic archaeon belonging to the order Sulfolobales (class Thermoprotei; phylum Crenarchaeota). While S. acidiphilus HS-1T shares many common physiological and phenotypic features with other Sulfolobales species, the similarities in their 16S rRNA gene sequences are less than 89%. In order to know the genomic features of S. acidiphilus HS-1T in the order Sulfolobales, we determined and characterized the genome of this strain. RESULTS: The circular genome of S. acidiphilus HS-1T is comprised of 2353,189 bp with a G+C content of 51.15 mol%. A total of 2459 genes were predicted, including 2411 protein coding and 48 RNA genes. The notable genomic features of S. acidiphilus HS-1T in Sulfolobales species are the absence of genes for polB3 and the autotrophic carbon fixation pathway, and the distribution pattern of essential genes and sequences related to genomic replication initiation. These insights contribute to an understanding of archaeal genomic diversity and evolution.


Assuntos
Proteínas Arqueais/genética , DNA Arqueal/genética , Genoma Arqueal/genética , Sulfolobaceae/genética , Sequenciamento Completo do Genoma/métodos , Composição de Bases/genética , DNA Arqueal/química , Ordem dos Genes , Genes Arqueais/genética , Genômica/métodos , Fontes Termais/microbiologia , Japão , Filogenia , RNA Ribossômico 16S/genética , Especificidade da Espécie , Sulfolobaceae/classificação , Sulfolobaceae/isolamento & purificação
5.
Arch Microbiol ; 201(10): 1351-1359, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31317227

RESUMO

A new taxon is created for the thermophilic purple nonsulfur bacterium previously designated as Rhodopseudomonas strain GI. Strain GI was isolated from a New Mexico (USA) hot spring microbial mat and grows optimally above 40 °C and to a maximum of 47 °C. Strain GI is a bacteriochlorophyll b-containing species of purple nonsulfur bacteria and displays a budding morphology, typical of species of the genus Blastochloris. Although resembling the species Blc. viridis in many respects, the absorption spectrum, carotenoid content, and lipid fatty acid profile of strain GI is distinct from that of Blc. viridis strain DSM133T and other recognized Blastochloris species. Strain GI forms its own subclade within the Blastochloris clade of purple nonsulfur bacteria based on comparative 16S rRNA gene sequences, and its genome is significantly larger than that of strain DSM133T; average nucleotide identity between the genomes of Blc. viridis and strain GI was below 85%. Moreover, concatenated sequence analyses of PufLM and DnaK clearly showed strain GI to be distinct from both Blc. viridis and Blc. sulfoviridis. Because of its unique assortment of properties, it is proposed to classify strain GI as a new species of the genus Blastochloris, as Blc. tepida, sp.n., with strain GIT designated as the type strain (= ATCC TSD-138 = DSM 106918).


Assuntos
Fontes Termais/microbiologia , Hyphomicrobiaceae/classificação , Hyphomicrobiaceae/fisiologia , Filogenia , Bacterioclorofilas/metabolismo , Classificação , DNA Bacteriano/genética , Hyphomicrobiaceae/química , Hyphomicrobiaceae/genética , RNA Ribossômico 16S/genética , Especificidade da Espécie
6.
Int J Syst Evol Microbiol ; 69(6): 1724-1730, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31038452

RESUMO

A Gram-stain-negative, aerobic, non-motile and coccus-shaped bacterium, designated strain FeSDHB5-19T, was isolated from a biofilm sample collected from a radioactive thermal spring (Budapest, Hungary), after exposure to 5 kGy gamma radiation. A polyphasic approach was used to study the taxonomic properties of strain FeSDHB5-19T, which had highest 16S rRNA gene sequence similarity to Deinococcus antarcticus G3-6-20T (96.5 %). The 16S rRNA gene sequence similarity to type strains of other Deinococcus species were 93.0 % or lower. The DNA G+C content of the draft genome sequence, consisting of 3.9 Mb, was 63.9 mol%. Strain FeSHDB5-19T was found to grow at temperatures of 10-32 °C (optimum, 28 °C) and pH 5-10 (pH 6.5-7.5) and tolerated up to 1.5 % NaCl (w/v) with optimum growth at 0-0.5 % NaCl. The predominant fatty acids (>10 %) were C16 : 0 and C16 : 1ω7c. The cell-wall peptidoglycan type was A3ß l-Orn-Gly1-2. The whole-cell sugars were glucose and low amounts of galactose. Strain FeSDHB5-19T possessed MK-8 as the predominant respiratory quinone, typical of the genus Deinococcus. The polar lipid profile contained unidentified phosphoglycolipids and unidentified glycolipids. The isolate was found to be highly resistant to gamma (D10<8 kGy) and UV (D10~800 J m-2) radiation. According to its genotypic, phenotypic and chemotaxonomic characteristics, strain FeSDHB5-19T represents a novel species in the genus Deinococcus, for which the name Deinococcusfonticola sp. nov. is proposed. The type strain is FeSDHB5-19T (=NCAIM B.02639T=DSM 106917T).


Assuntos
Deinococcus/classificação , Raios gama , Fontes Termais/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Deinococcus/isolamento & purificação , Ácidos Graxos/química , Glicolipídeos/química , Hungria , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
7.
Sci Total Environ ; 679: 52-60, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31082602

RESUMO

Applicability of thermophilic and thermo-tolerant microorganisms for biodegradation of polycyclic aromatic hydrocarbons (PAHs) with low water solubility is an interesting strategy for improving the biodegradation efficiency. In this study, we evaluated utility of thermophilic and thermo-tolerant bacteria isolated from Unkeshwar hot spring (India) for biodegradation of four different PAHs. Water samples were enriched in mineral salt medium (MSM) containing a mixture of four PAHs compounds (anthracene: ANT, fluorene: FLU, phenanthrene: PHE and pyrene: PYR) at 37 °C and 50 °C. After growth based screening, four potent strains obtained which were identified as Aeribacillus pallidus (UCPS2), Bacillus axarquiensis (UCPD1), Bacillus siamensis (GHP76) and Bacillus subtilis subsp. inaquosorum (U277) based on the 16S rRNA gene sequence analysis. Degradation of mixed PAH compounds was evaluated by pure as well as mixed cultures under shake flask conditions using MSM supplemented with 200 mg/L concentration of PAHs (50 mg/L of each compound) for 15 days at 37 °C and 50 °C. A relatively higher degradation of ANT (92%- 96%), FLU (83% - 86%), PHE (16% - 54%) and PYR (51% - 71%) was achieved at 50 °C by Aeribacillus sp. (UCPS2) and mixed culture. Furthermore, crude oil was used as a substrate to study the degradation of same PAHs using these organisms which also revealed with similar results with the higher degradation at 50 °C. Interestingly, PAH-degrading strains were also positive for biosurfactant production. Biosurfactants were identified as the variants of surfactins (lipopeptide biosurfactants) based on analytical tools and phylogenetic analysis of the surfactin genes. Overall, this study has shown that hot spring microbes may have a potential for PAHs degradation and also biosurfactant production at a higher temperature, which could provide a novel perspective for removal of PAHs residues from oil contaminated sites.


Assuntos
Bactérias/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Fontes Termais/microbiologia , Índia , Tensoativos , Termotolerância
8.
Int J Syst Evol Microbiol ; 69(7): 2064-2068, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31091184

RESUMO

A Gram-stain-positive, aerobic, coccoid-shaped, non-spore-forming actinobacterial strain, designated M5W7-7T, was isolated from a hot spring soil sample collected from Anshan, Liaoning province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain M5W7-7T clustered closely with species of the genus Kocuria, and showed the highest sequence similarity of 97.1 % to Kocuria subflava YIM 13062T. Strain M5W7-7T grew at 10-37 °C (optimum, 37 °C), pH6.0-11.0 (pH 6.0-7.0) and in the presence of 0-7 % (w/v) NaCl (0 %). Substrate mycelia and aerial mycelia were not formed, and diffusible pigments were not observed on any media tested. Strain M5W7-7T contained MK-6(H2) and MK-7(H2) as the dominant menaquinones. The polar lipid profile of strain M5W7-7T contained diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids, an unidentified phospholipid and an unidentified lipid. The predominant whole-cell sugars were galactose and glucose. The predominant fatty acid was anteiso-C15 : 0. The DNA G+C content of strain M5W7-7T was 67.0 mol%. On the basis of phylogenetic relationships, phenotypic characterization and chemotaxonomic analyses, strain M5W7-7T represents a novel species of the genus Kocuria, for which the name Kocuriasoli sp. nov. is proposed. The type strain is M5W7-7T (=KCTC 49195T =CGMCC 1.13744T).


Assuntos
Fontes Termais/microbiologia , Micrococcaceae/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Micrococcaceae/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/química
9.
J Basic Microbiol ; 59(6): 569-578, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30980727

RESUMO

The biocompatible-coated iron oxide nanoparticles (IONs) have attracted a great interest because of their various applications in biological science and medicine. In most cases, the toxic effect of naked iron oxide nanoparticles is completely cleared by adding a biocompatible coating, such as polysaccharides, polyethylene glycol (PEG), or biosynthesis of biocompatible-coated IONs using microorganisms such as bacteria. In the present study, polysaccharide-coated iron oxide nanoparticles were produced by a strain of Staphylococcus warneri isolated from a thermal spring. For identification of the isolated bacterium, 16S rRNA gene sequencing was done. Characterization of the nanoparticles was performed for the first time, using transmission electron microscopy (TEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA), X-ray crystallography (XRD), Fourier-transform infrared (FTIR) spectroscopy, vibrating sample magnetometer (VSM), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results indicated that the spherical iron oxide nanoparticles were coated by a polysaccharide (13.6%), which provided a large negative charge of -91 mV and very low saturation magnetization of around 0.28 emu/g. The result of MTT assay on MOLT-4 cell lines showed that the percentage of viability was between 95.6% and 68.9% in the 10-100 µM of nanoparticle concentrations with a high IC 50 value, which makes it appropriate for biomedical applications such as cancer therapy.


Assuntos
Materiais Biocompatíveis/química , Fontes Termais/microbiologia , Nanopartículas de Magnetita/química , Polissacarídeos Bacterianos/química , Staphylococcus/metabolismo , Materiais Biocompatíveis/isolamento & purificação , Materiais Biocompatíveis/metabolismo , Materiais Biocompatíveis/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Campos Magnéticos , Nanopartículas de Magnetita/ultraestrutura , Tamanho da Partícula , Polissacarídeos Bacterianos/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Staphylococcus/classificação , Staphylococcus/genética , Staphylococcus/isolamento & purificação
10.
Int J Syst Evol Microbiol ; 69(6): 1737-1743, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30958256

RESUMO

A moderately thermophilic, aerobic, Gram-stain-negative, non-spore-forming, rod-shaped and yellow-pigmented bacterium, designated strain SYSU G00007T, was isolated from a hot spring slurry sample. Optimum growth was observed at 37-45 °C and pH 7. Pairwise comparison of the 16S rRNA gene sequence of strain SYSU G00007T and other Novosphingobium species showed sequence similarities ranging from 93.7 to 97.9 %. Strain SYSU G00007T showed highest sequence identity to Novosphingobium subterraneum DSM 12447T (97.9 %). The average nucleotide identities and digital DNA-DNA hybridization values between strain SYSU G00007T and its closely related phylogenetic neighbours were below 81 and 31 %, respectively, indicating that strain SYSU G00007T represented a novel species of the genus Novosphingobium. The DNA G+C content of strain SYSU G00007T was 64.3 % (genome). The major respiratory quinone was ubiquinone Q-10. The polar lipid profile included diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, two sphingoglycolipids, two unidentified phospholipids, two unidentified aminophospholipids and two unidentified polar lipids. Spermidine was the only polyamine detected. The major fatty acids were C19 : 0cyclo ω8c, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The results obtained from phylogenetic, chemotaxonomic and phenotypic analyses support the conclusion that strain SYSU G00007T represents a novel species of the genus Novosphingobium, for which we proposed the name Novosphingobiummeiothermophilum sp. nov. The type strain is SYSU G00007T (=KCTC 52672T=CCTCC AB2017010T).


Assuntos
Fontes Termais/microbiologia , Filogenia , Sphingomonadaceae/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espermidina/química , Sphingomonadaceae/isolamento & purificação , Ubiquinona/química
11.
J Basic Microbiol ; 59(7): 680-691, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30997929

RESUMO

Although arsenic (As) is recognized as a toxic element for living species, some microorganisms have the ability to tolerate and transform it; recent studies have proposed to take advantage of such capacity to develop sustainable bioremediation strategies. In this study, we evaluated the adaptation to increasing concentrations of As(III) and As(V) of three metabolically different microbial cultures (heterotrophic, autotrophic-acidophilic, and anaerobic) obtained from a sample with low-soluble As content from the Copahue geothermal system. At the end of the adaptation process, the heterotrophic culture was able to grow at 20 mM and 450 mM of As(III) and As(V), respectively; the autotrophic-acidophilic culture showed tolerance to 15 mM of As(III) and 150 mM of As(V), whereas the anaerobic culture only developed in As(V) at concentrations up to 50 mM. The most tolerant consortia were characterized by their growth performance, complexity, and the presence of genes related to As metabolism and resistance. Regarding the consortia complexity, the predominant genera identified were: Paenibacillus in both heterotrophic consortia, Acidithiobacillus in the autotrophic-acidophilic consortium tolerant to As(III), Acidiphilium in the autotrophic-acidophilic consortium tolerant to As(V), and Thiomonas and Clostridium in the anaerobic consortium. This study is the first report of As tolerance microorganisms obtained from Copahue and reasserts the versatility and flexibility of the community of this natural extreme environment; also, it opens the door to the study of possible uses of these consortia in the design of biotechnological processes where the As concentration may fluctuate.


Assuntos
Adaptação Fisiológica/fisiologia , Arsênico/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Sedimentos Geológicos/microbiologia , Fontes Termais/microbiologia , Consórcios Microbianos/fisiologia , Adaptação Fisiológica/genética , Anaerobiose , Argentina , Arsênico/química , Processos Autotróficos , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodiversidade , Meios de Cultura/química , Sedimentos Geológicos/química , Processos Heterotróficos , Fontes Termais/química , Consórcios Microbianos/genética
12.
Arch Microbiol ; 201(7): 969-982, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31030239

RESUMO

In hydrothermal environments, carbon monoxide (CO) utilisation by thermophilic hydrogenogenic carboxydotrophs may play an important role in microbial ecology by reducing toxic levels of CO and providing H2 for fuelling microbial communities. We evaluated thermophilic hydrogenogenic carboxydotrophs by microbial community analysis. First, we analysed the correlation between carbon monoxide dehydrogenase (CODH)-energy-converting hydrogenase (ECH) gene cluster and taxonomic affiliation by surveying an increasing genomic database. We identified 71 genome-encoded CODH-ECH gene clusters, including 46 whose owners were not reported as hydrogenogenic carboxydotrophs. We identified 13 phylotypes showing > 98.7% identity with these taxa as potential hydrogenogenic carboxydotrophs in hot springs. Of these, Firmicutes phylotypes such as Parageobacillus, Carboxydocella, Caldanaerobacter, and Carboxydothermus were found in different environmental conditions and distinct microbial communities. The relative abundance of the potential thermophilic hydrogenogenic carboxydotrophs was low. Most of them did not show any symbiotic networks with other microbes, implying that their metabolic activities might be low.


Assuntos
Biodiversidade , Sedimentos Geológicos/microbiologia , Fontes Termais/microbiologia , Hidrogenase/genética , Microbiota/fisiologia , Aldeído Oxirredutases/metabolismo , Monóxido de Carbono/metabolismo , Firmicutes/fisiologia , Hidrogenase/metabolismo , Japão , Microbiota/genética , Complexos Multienzimáticos/metabolismo , Família Multigênica/genética
13.
Arch Microbiol ; 201(7): 951-967, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31025055

RESUMO

With the advent of new molecular tools, new taxa of sulphur-oxidising bacteria (SOB) in diverse environments are being discovered. However, there is a significant gap of knowledge about the ecology and diversity of SOB in thermal springs. Here, the species diversity and phylogenetic affiliations of SOB were investigated using 16S rRNA and functional gene marker, soxB in thermal springs of Thane district of Maharashtra, India. Most SOB detected by 16S rDNA sequences belong to different operational taxonomic units (OTU's): Firmicutes, α-, ß-, γ-Proteobacteria and Actinobacteria with the dominance of first class. However, the soxB gene clone library sequences had shown affiliation with the ß-, γ- and α-Proteobacteria. ß-Proteobacteria-related sequences were dominant, with 53.3% clones belonging to genus Hydrogenophaga. The thiosulphate oxidation assay carried out for different isolates having distinct identity showed the mean sulphate-sulphur production from 117.86 ± 0.50 to 218.82 ± 2.56 mg SO4-S l-1 after 9 days of incubation. Also, sulphur oxidation by the genus Nitratireductor, Caldimonas, Geobacillus, Paenibacillus, Brevibacillus, Tristrella and Chelatococcus has been reported for the first time that reveals ecological widening over which thiotrophs are distributed.


Assuntos
Bactérias/classificação , Bactérias/genética , Biodiversidade , Marcadores Genéticos/genética , Fontes Termais/microbiologia , RNA Ribossômico 16S/genética , Actinobacteria/genética , Betaproteobacteria/genética , DNA Bacteriano/genética , Gammaproteobacteria/genética , Índia , Oxirredução , Filogenia , Enxofre/metabolismo
14.
Environ Pollut ; 249: 696-702, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30933767

RESUMO

Antibiotic resistance (AR) in the environment is a growing and global concern for public health, and intrinsic AR from pristine sites untouched by pharmaceutical antibiotics is not commonly studied. Forty aerobic bacteria were isolated from water and sediment samples of hot springs in South Africa. Resistance against ten antibiotics (carbenicillin, gentamicin, kanamycin, streptomycin, tetracycline, chloramphenicol, ceftriaxone, co-trimoxazole, nalidixic acid and norfloxacin) was tested using a standard disk diffusion assay. Resistance to one or two antibiotics were equally found in 37.5%, while the remaining 22% showed complete sensitivity. Intermediate resistance was found for ceftriaxone (52.5%), nalidixic acid (37.5%) and carbenicillin (22.5%), while low levels of resistance were observed for streptomycin (5%) and kanamycin (2.5%), and total sensitivity towards the other antibiotics. Twenty-nine isolates were also tested against eight different heavy-metal salts (Al, Cr, Cu, Fe, Hg, Mn, Ni and Pb) at 10 and 40 mM. All isolates were tolerant and able to grow on ≥2 heavy-metal salts at both concentrations. No association was observed between AR and heavy metal tolerance (HMT). Based on the relatively low AR levels, hot spring sites are pristine environments reflecting baseline levels for comparison to other potentially contaminated groundwater sites.


Assuntos
Antibacterianos/análise , Bacillaceae/efeitos dos fármacos , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Fontes Termais/química , Metais Pesados/análise , Poluentes Químicos da Água/análise , Antibacterianos/toxicidade , Bacillaceae/isolamento & purificação , DNA Bacteriano/genética , Relação Dose-Resposta a Droga , Tolerância a Medicamentos , Água Subterrânea/química , Água Subterrânea/microbiologia , Fontes Termais/microbiologia , Metais Pesados/toxicidade , Testes de Sensibilidade Microbiana , África do Sul , Poluentes Químicos da Água/toxicidade
15.
Arch Microbiol ; 201(6): 795-805, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30868175

RESUMO

This is the comparative investigation of the composition of phototrophic microbial mats developing in sulfide-rich saline Chokrak springs with outflow at the shore of the hypersaline lake Chokrak by means of next-generation sequencing. The springs are characterized by low temperature (~ 15 °C), near-neutral pH (6.7-8.5), and high-sulfide content. In the species composition the benthic microbial communities of Chokrak springs are similar to microbial mats of marine supralittoral and lagoons. Our results showed that salinity limitation had a significant effect on the species composition of benthic microbial communities developing at the outflow of the Chokrak springs. Predominant oxygenic phototrophs belonged to the genera Phormidium, Lyngbya, Leptolyngbya, Geitlerinema, and Arthrospira. Anoxygenic phototrophic bacteria were represented by halophilic green sulfur bacteria Prosthecochloris spp., halotolerant Chlorobaculum sp., as well as marine and extremely halophilic purple bacteria Roseospira, Rhodovibrio, and Halochromatium. Monoculture of a new species of halotolerant anoxygenic filamentous phototrophic bacteria was isolated.


Assuntos
Bactérias/isolamento & purificação , Fontes Termais/microbiologia , Lagos/microbiologia , Microbiota , Sulfetos/metabolismo , Bactérias/classificação , Bactérias/metabolismo , Fontes Termais/análise , Concentração de Íons de Hidrogênio , Lagos/análise , Processos Fototróficos , Filogenia , Salinidade , Sulfetos/análise , Enxofre/análise , Enxofre/metabolismo
16.
J Environ Radioact ; 203: 8-17, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30844681

RESUMO

The thermal waters of Gellért Hill discharge area of the Buda Thermal Karst System (Hungary) are characterized by high (up to 1000 Bq/L) 222Rn-activity due to the radium-accumulating biogeochemical layers. Samples were taken from these ferruginous and calcareous layers developed on spring cave walls and water surface. Accumulation of potentially toxic metals (e.g. As, Hg, Pb, Sn, Sr, Zn) in the dense extracellular polymeric substance containing bacterial cells and remains was detected by inductively coupled plasma mass spectrometry. The comparison of bacterial phylogenetic diversity of the biofilm samples was performed by high throughput next generation sequencing (NGS). The analysis showed similar sets of mainly unidentified taxa of phyla Chloroflexi, Nitrospirae, Proteobacteria, Planctomycetes; however, large differences were found in their abundance. Cultivation-based method complemented with irradiation assay was performed using 5, 10 and 15 kGy doses of gamma-rays from a 60Co-source to reveal the extreme radiation-resistant bacteria. The phyla Actinobacteria, Firmicutes, Proteobacteria (classes Alpha- Beta- and Gammaproteobacteria), Bacteriodetes and Deinococcus-Thermus were represented among the 452 bacterial strains. The applied irradiation treatments promoted the isolation of 100 different species, involving candidate novel species, as well. The vast majority of the isolates belonged to bacterial taxa previously unknown as radiation-resistant microorganisms. Members of the genera Paracoccus, Marmoricola, Dermacoccus and Kytococcus were identified from the 15 kGy dose irradiated samples. The close relatives of several known radiation-tolerant bacteria were also detected from the biofilm samples, alongside with bacteria capable of detoxification by metal accumulation, adsorption and precipitation in the form of calcium-carbonate which possibly maintain the viability of the habitat. The results suggest the establishment of a unique, extremophilic microbiota in the studied hydrothermal spring caves.


Assuntos
Adaptação Fisiológica/fisiologia , Bactérias/crescimento & desenvolvimento , Cavernas/microbiologia , Fontes Termais/microbiologia , Radiação de Fundo , Biofilmes/crescimento & desenvolvimento , Matriz Extracelular de Substâncias Poliméricas , Hungria , Monitoramento de Radiação , Rádio (Elemento)
17.
J Appl Microbiol ; 126(6): 1742-1750, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30817048

RESUMO

AIMS: Hot springs have always drawn attention due to their unique chemical richness and the presence of different microbial communities. The use of hot spring bacteria in concrete technology is our primary focus; isolation of an alkaliphilic bacterium from the Bakreshwar hot springs having longer survival and better efficacy towards cementitious environment was the basis of our study's design. METHODS AND RESULTS: A novel facultative anaerobic and highly alkaliphilic bacterial strain (BKH4; GenBank accession no. KX622782) belonging to the family 'Bacillaceae' and homologous (99%) with Lysinibacillus fusiformis was isolated from Bakreshwar hot springs. The isolated coccoid-type Gram-positive bacterium grows well in a defined semi-synthetic medium (pH 12·0 and 65°C). This bacterium survives for more than a month and shows better efficacy in enhancing compressive strengths (>50%), ultrasonic pulse velocity (>25%) and durability of the cementitious mortar when incorporated at a concentration of 104  cells per ml of water used. CONCLUSION: The novel bacterium BKH4 is more effective for the enhancement of the bioconcrete properties. SIGNIFICANCE AND IMPACT OF THE STUDY: BKH4 bacterium will add a new dimension to future concrete technology for its usefulness in strength enhancement and durability due to its alkaliphilic nature and longer survival within a cementitious environment.


Assuntos
Álcalis/metabolismo , Bacillaceae/fisiologia , Biotecnologia , Materiais de Construção/microbiologia , Fontes Termais/microbiologia , Bacillaceae/genética , Bacillaceae/metabolismo , Força Compressiva , DNA Bacteriano/genética , Temperatura Alta , Concentração de Íons de Hidrogênio , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
18.
Int J Syst Evol Microbiol ; 69(5): 1336-1342, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30810517

RESUMO

A single spore forming actinomycete, designated strain HSS6-8T, was isolated from a sample of hot spring soil. The strain had the chemotaxonomic properties consistent with its classification in the genus Micromonospora. The strain was found to have meso-diaminopimelic acid in the cell-wall peptidoglycan. The acyl type of the cell-wall muramic acid was glycolyl. The reducing sugars in the cell hydrolysates were glucose, arabinose, xylose, ribose, mannose, galactose and rhamnose. The phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphoglycolipid. The major menaquinones were MK-10(H6) and MK-10(H4). The major cellular fatty acids were iso-C16 : 0, anteiso-C17 : 0, C17 : 0 and anteiso-C15 : 0. The G+C content of the genomic DNA was 70.5 mol%. 16S rRNA gene sequence analysis revealed that strain HSS6-8T was closely related to Micromonospora nigra DSM 43818T (98.2 %), Micromonospora eburnea DSM 44814T (98.2 %) and Micromonospora spongicola S3-1T (98.1 %). The physiological and DNA-DNA hybridization data allowed the differentiation of strain HSS6-8T from its related species. Thus, the strain represents a novel species of the genus Micromonospora, for which the name Micromonospora caldifontis sp. nov. is proposed. The type strain is HSS6-8T (=TBRC 8927T=JCM 17126T).


Assuntos
Fontes Termais/microbiologia , Micromonospora/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Micromonospora/isolamento & purificação , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Tailândia , Vitamina K 2/química
19.
Toxins (Basel) ; 11(2)2019 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-30747108

RESUMO

Organisms adaptable to extreme conditions share the ability to establish protective biofilms or secrete defence toxins. The extracellular substances that are secreted may contain monosaccharides and other toxic compounds, but environmental conditions influence biofilm characteristics. Microorganisms that are present in the same environment achieve similar compositions, regardless of their phylogenetic relationships. Alternatively, cyanobacteria phylogenetically related may live in different environments, but we ignore if their physiological answers may be similar. To test this hypothesis, two strains of cyanobacteria that were both ascribed to the genus Halomicronema were isolated. H. metazoicum was isolated in marine waters off the island of Ischia (Bay of Naples, Italy), free living on leaves of Posidonia oceanica. Halomicronema sp. was isolated in adjacent thermal waters. Thus, two congeneric species adapted to different environments but diffused in the same area were polyphasically characterized by microscopy, molecular, and toxicity analyses. A variable pattern of toxicity was exhibited, in accordance with the constraints imposed by the host environments. Cyanobacteria adapted to extreme environments of thermal waters face a few competitors and exhibit a low toxicity; in contrast, congeneric strains that have adapted to stable and complex environments as seagrass meadows compete with several organisms for space and resources, and they produce toxic compounds that are constitutively secreted in the surrounding waters.


Assuntos
Alismatales/microbiologia , Cianobactérias/isolamento & purificação , Fontes Termais/microbiologia , Animais , Cianobactérias/genética , Embrião não Mamífero/microbiologia , Monitoramento Ambiental , Pradaria , Ilhas , Itália , Filogenia , Folhas de Planta/microbiologia , RNA Ribossômico 16S , Ouriços-do-Mar/microbiologia , Água do Mar/microbiologia , Especificidade da Espécie
20.
Extremophiles ; 23(3): 277-281, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30741334

RESUMO

DGGE analysis combined with a metagenomic approach was used to get insights into heterotrophic anoxic enrichment cultures of four hot springs of Vale das Furnas, Portugal, using the recalcitrant substrate spent coffee ground (SCG). Parallel enrichment cultures were performed using the major components of spent coffee ground, namely arabinogalactan, galactomannan, cellulose, and proteins. DGGE revealed that heterotrophic thermophilic bacteria are highly abundant in the hydrothermal springs and significant differences in community composition depending on the substrate were observed. DNA, isolated from enrichment cultures of different locations that were grown on the same substrate were pooled, and the respective metagenomes were analyzed. Results indicated that cultures grown on recalcitrant substrate SCG consists of a totally different thermophilic community, dominated by Dictyoglomus. Enrichments with galactomannan and arabinogalactan were dominated by Thermodesulfovibrio, while cultures with casein and cellulose were dominated by Thermus. This study indicates the high potential of thermophilic bacteria degrading recalcitrant substrate such as SCG and furthermore how the accessibility to complex polymers shapes the bacterial community.


Assuntos
Archaea , Bactérias , Biodiversidade , Fontes Termais/microbiologia , Metagenoma , Microbiologia da Água , Archaea/classificação , Archaea/genética , Archaea/crescimento & desenvolvimento , Archaea/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Metagenômica , Portugal
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