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1.
Gene ; 812: 146103, 2022 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-34896522

RESUMO

Characterization of hot spring microbiota is useful as an initial platform for exploring industrially important microbes. The present study focused on characterization of microbiota in four hot springs in Sri Lanka: Maha Oya; Wahava; Madunagala; and Kivlegama using high throughput 16S amplicon sequencing. Temperatures of the selected springs were ranged from 33.7 °C to 52.4 °C, whereas pH ranged from 7.2 to 8.2. Bacteria were found to be the dominant microbial group (>99%) compared to Archaea which represented less than 1% of microbiota. Four hot springs comprised of unique microbial community structures. Proteobacteria, Firmicutes, Bacteroidetes, Cloroflexi, Deinococcus and Actenobacteria were the major bacterial phyla. Moderately thermophilic genera such as Thermodesulfobacteria and Deinococcus-Thermus were detected as major genera that could be used in industrial applications operating at temperatures around 50 °C and alkaline reaction conditions.


Assuntos
Archaea/classificação , Bactérias/classificação , Fontes Termais/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA/métodos , Archaea/genética , Archaea/isolamento & purificação , Bactérias/genética , Bactérias/isolamento & purificação , DNA Ribossômico/genética , Sequenciamento de Nucleotídeos em Larga Escala , Fontes Termais/análise , Microbiota , Filogenia , Sri Lanka
2.
J Prev Med Hyg ; 62(2): E479-E488, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34604589

RESUMO

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.


Assuntos
Antibacterianos , Bactérias/classificação , Fontes Termais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Balneologia , Fontes Termais/microbiologia , Itália , Testes de Sensibilidade Microbiana
3.
Biomed Res Int ; 2021: 1869748, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34258259

RESUMO

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.


Assuntos
Anoxybacillus/genética , Análise de Dados , Fontes Termais/microbiologia , Sequenciamento Completo do Genoma , Sequência de Aminoácidos , Anoxybacillus/enzimologia , Anoxybacillus/ultraestrutura , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , DNA Circular/genética , Genoma Bacteriano , Glicosídeo Hidrolases/metabolismo , Anotação de Sequência Molecular , Nepal , Fases de Leitura Aberta/genética , Filogenia , Xilose/metabolismo
4.
Syst Appl Microbiol ; 44(4): 126230, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34293647

RESUMO

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.


Assuntos
Fontes Termais/microbiologia , Filogenia , Thermofilaceae , Técnicas de Tipagem Bacteriana , Composição de Bases , Chile , DNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Thermofilaceae/classificação , Thermofilaceae/isolamento & purificação
5.
Int J Biol Macromol ; 185: 277-286, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34147526

RESUMO

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.


Assuntos
Bacillus licheniformis/isolamento & purificação , Fontes Termais/microbiologia , Ácidos Indolacéticos/metabolismo , Proteínas de Membrana Transportadoras/química , Proteínas de Membrana Transportadoras/genética , Sequência de Aminoácidos , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transporte Biológico , Índia , Proteínas de Membrana Transportadoras/metabolismo , Metagenômica , Modelos Moleculares , Simulação de Dinâmica Molecular , Domínios Proteicos , Estrutura Terciária de Proteína
6.
Microbes Environ ; 36(2)2021.
Artigo em Inglês | MEDLINE | ID: mdl-34108360

RESUMO

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.


Assuntos
Caldicellulosiruptor/isolamento & purificação , Caldicellulosiruptor/fisiologia , Fixação de Nitrogênio , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Caldicellulosiruptor/classificação , Caldicellulosiruptor/genética , Fermentação , Genoma Bacteriano , Fontes Termais/química , Fontes Termais/microbiologia , Temperatura Alta , Nitrogênio/metabolismo , Nitrogenase/química , Nitrogenase/genética , Nitrogenase/metabolismo , Filogenia
7.
Artigo em Inglês | MEDLINE | ID: mdl-34003738

RESUMO

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).


Assuntos
Clostridiales/classificação , Fontes Termais/microbiologia , Filogenia , Anaerobiose , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Clostridiales/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Fermentação , Nova Caledônia , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
8.
Microbes Environ ; 36(2)2021.
Artigo em Inglês | MEDLINE | ID: mdl-33952861

RESUMO

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.


Assuntos
Genoma Bacteriano , Thermosynechococcus/genética , Thermosynechococcus/isolamento & purificação , Adaptação Fisiológica , Ecossistema , Genômica , Fontes Termais/microbiologia , Japão , Filogenia , Thermosynechococcus/classificação , Thermosynechococcus/fisiologia
9.
Int J Mol Sci ; 22(6)2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33799806

RESUMO

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.


Assuntos
Proteínas de Bactérias/metabolismo , Biomineralização , Dióxido de Carbono/metabolismo , Anidrases Carbônicas/metabolismo , Sequência de Aminoácidos , Bactérias/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Dióxido de Carbono/química , Anidrases Carbônicas/química , Anidrases Carbônicas/genética , Catálise , Domínio Catalítico , Simulação por Computador , Fontes Termais/microbiologia , Fontes Hidrotermais/microbiologia , Simulação de Dinâmica Molecular , Conformação Proteica , Homologia de Sequência de Aminoácidos , Temperatura , Thermus thermophilus/enzimologia
10.
Nat Commun ; 12(1): 2404, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33893309

RESUMO

Geothermal environments, such as hot springs and hydrothermal vents, are hotspots for carbon cycling and contain many poorly described microbial taxa. Here, we reconstructed 15 archaeal metagenome-assembled genomes (MAGs) from terrestrial hot spring sediments in China and deep-sea hydrothermal vent sediments in Guaymas Basin, Gulf of California. Phylogenetic analyses of these MAGs indicate that they form a distinct group within the TACK superphylum, and thus we propose their classification as a new phylum, 'Brockarchaeota', named after Thomas Brock for his seminal research in hot springs. Based on the MAG sequence information, we infer that some Brockarchaeota are uniquely capable of mediating non-methanogenic anaerobic methylotrophy, via the tetrahydrofolate methyl branch of the Wood-Ljungdahl pathway and reductive glycine pathway. The hydrothermal vent genotypes appear to be obligate fermenters of plant-derived polysaccharides that rely mostly on substrate-level phosphorylation, as they seem to lack most respiratory complexes. In contrast, hot spring lineages have alternate pathways to increase their ATP yield, including anaerobic methylotrophy of methanol and trimethylamine, and potentially use geothermally derived mercury, arsenic, or hydrogen. Their broad distribution and their apparent anaerobic metabolic versatility indicate that Brockarchaeota may occupy previously overlooked roles in anaerobic carbon cycling.


Assuntos
Archaea/genética , Ciclo do Carbono/genética , Genoma Arqueal/genética , Metagenoma/genética , Filogenia , Archaea/classificação , Archaea/metabolismo , Carbono/metabolismo , China , Geografia , Sedimentos Geológicos/microbiologia , Fontes Termais/microbiologia , Fontes Hidrotermais/microbiologia , Metano/metabolismo , RNA Ribossômico 16S/genética , Especificidade da Espécie
11.
FEMS Microbiol Lett ; 368(6)2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33856450

RESUMO

Classical Bordetella species are primarily isolated from animals and humans causing asymptomatic infection to lethal pneumonia. However, isolation of these bacteria from any extra-host environmental niche has not been reported so far. Here, we have characterized the genomic plasticity and antibody response of Bordetella bronchiseptica strain HT200, isolated from a thermal spring. Genomic ANI value and SNPs-based phylogenetic tree suggest a divergent evolution of strain HT200 from a human-adapted lineage of B. bronchiseptica. Growth and survivability assay showed strain HT200 retained viability for more than 5 weeks in the filter-sterilized spring water. In addition, genes or loci encoding the Bordetella virulence factors such as DNT, ACT and LPS O-antigen were absent in strain HT200, while genes encoding other virulence factors were highly divergent. Phenotypically, strain HT200 was non-hemolytic and showed weak hemagglutination activity, but was able to colonize in the respiratory organs of mice. Further, both infection and vaccination with strain HT200 induced protective antibody response in mouse against challenge infection with virulent B. bronchiseptica strain RB50. In addition, genome of strain HT200 (DSM 26023) showed presence of accessory genes and operons encoding predicted metabolic functions pertinent to the ecological conditions of the thermal spring.


Assuntos
Formação de Anticorpos , Bordetella bronchiseptica , Fontes Termais , Animais , Anticorpos Antibacterianos/sangue , Formação de Anticorpos/imunologia , Vacinas Bacterianas/imunologia , Bordetella bronchiseptica/genética , Bordetella bronchiseptica/imunologia , Bordetella bronchiseptica/patogenicidade , Variação Genética , Fontes Termais/microbiologia , Camundongos , Polimorfismo de Nucleotídeo Único , Sistema Respiratório/microbiologia , Fatores de Virulência/genética
12.
Syst Appl Microbiol ; 44(2): 126184, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33676265

RESUMO

Recently, presence of sulfur-disproportionating bacterial species belonging to the phylum Nitrospirota was indicated by an enrichment culture-based study. In the present study, a strain representing that species was isolated and characterized. The strain, strain T55JT, was isolated from a microbial mat of a hot spring. The cells were motile, and rods or spiral forms with width of 0.32-0.49 µm. The strain grew autotrophically, only by disproportionation of thiosulfate or elemental sulfur. Growth was observed at a temperature range of 25-60°C, with optimum growth at 53-57°C. The pH range for growth was 5.5-9.0, with optimum pH of 7.0-8.0. The complete genome of strain T55JT is composed of a circular chromosome (2,370,875 bp), with G+C content of 38.7%. Thermodesulfovibrio hydrogeniphilus Hdr5T showed the highest sequence similarity of the 16S rRNA gene to strain T55JT, but it was only 88.2%. On the basis of the phylogenetic and physiologic properties, strain T55JT (= DSM 110365T=NBRC 114245T) is proposed as type strain of a novel species in a new genus, Dissulfurispira thermophila gen. nov., sp. nov. To assign the new genus to family and higher taxa, its taxonomic position was assessed by genome-based phylogeny. As a result, it was shown that the novel genus and Thermodesulfovibrio belong to different families. It was also shown that Thermodesulfovibrio should be reclassified at levels from class to family and creation of some novel taxa is required. Based on these results, Thermodesulfovibrionia class. nov., Thermodesulfovibrionales ord. nov., Thermodesulfovibrionaceae fam. nov., and Dissulfurispiraceae fam. nov. are proposed.


Assuntos
Bactérias/classificação , Fontes Termais/microbiologia , Filogenia , Enxofre , Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Enxofre/metabolismo
13.
Folia Microbiol (Praha) ; 66(3): 457-468, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33755859

RESUMO

Fungi are considered to be the most resilient and economically important microbial community that can easily survive and optimally grow under a wide range of growth conditions. Thermophilic fungi from the geothermal sources have been less pondered upon and lie unexplored. Here, a microbiome approach was conducted to understand the concealed world of the environmental mycobiota from the two hot springs of North Sikkim district located in North-east India. The solfataric muds from the hot springs were analyzed. In both the samples, on the basis of genus level classification, genus Fusarium had the highest abundance followed by Colletotrichum, Pochonia, Pyricularia, Neurospora, etc. Analyzing the predicted genes, the functional proteins of New Yume Samdung mycobiome were found to be dominated by the genera Fusarium (22%), Trichoderma (12%), and Aspergillus (11%), whereas in the case of Old Yume Samdung, it was dominated by the genera Aspergillus (11%), Saccharomyces (6%), and Fusarium (5%). Interestingly, in the studied mycobiome, environmental yeasts were also detected. From the functional metagenomics, sulfate adenylatetransferase (SAT) proteins for sulfur assimilation were found in some of the fungal reads. Toxin protein reads such as AM-toxin biosynthesis proteins, AF-toxin biosynthesis proteins, Gliotoxin biosynthesis proteins, and aflatoxin biosynthesis proteins were detected in the mycobiomes.


Assuntos
Biodiversidade , Fungos , Fontes Termais , Micobioma , Fungos/fisiologia , Fontes Termais/microbiologia , Metagenômica , Micobioma/fisiologia , Siquim
14.
Sci Rep ; 11(1): 101, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420292

RESUMO

In the present study we investigate the microbial community inhabiting As Burgas geothermal spring, located in Ourense (Galicia, Spain). The approximately 23 Gbp of Illumina sequences generated for each replicate revealed a complex microbial community dominated by Bacteria in which Proteobacteria and Aquificae were the two prevalent phyla. An association between the two most prevalent genera, Thermus and Hydrogenobacter, was suggested by the relationship of their metabolism. The high relative abundance of sequences involved in the Calvin-Benson cycle and the reductive TCA cycle unveils the dominance of an autotrophic population. Important pathways from the nitrogen and sulfur cycle are potentially taking place in As Burgas hot spring. In the assembled reads, two complete ORFs matching GH2 beta-galactosidases were found. To assess their functional characterization, the two ORFs were cloned and overexpressed in E. coli. The pTsbg enzyme had activity towards o-Nitrophenyl-ß-D-galactopyranoside (ONPG) and p-Nitrophenyl-ß-D-fucopyranoside, with high thermal stability and showing maximal activity at 85 °C and pH 6, nevertheless the enzyme failed to hydrolyze lactose. The other enzyme, Tsbg, was unable to hydrolyze even ONPG or lactose. This finding highlights the challenge of finding novel active enzymes based only on their sequence.


Assuntos
Bactérias/enzimologia , Bactérias/isolamento & purificação , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Fontes Termais/microbiologia , beta-Galactosidase/química , beta-Galactosidase/metabolismo , Bactérias/classificação , Bactérias/genética , Proteínas de Bactérias/genética , Estabilidade Enzimática , Temperatura Alta , Concentração de Íons de Hidrogênio , Filogenia , beta-Galactosidase/genética
15.
J Appl Microbiol ; 130(4): 1394-1400, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32985039

RESUMO

AIMS: Due to infectious risk associated with the presence of Legionella in warm water, we determined the prevalence of living Legionella spp. in hot spring water in Algeria. METHODS AND RESULTS: Detection of Legionella by culture was done by using two methods, direct culture on agar plates and co-culture with amoeba. Fifty samples were taken from different hot springs in northern Algeria, including swimming pools, showers and thermal sources. Legionella pneumophila serotypes were predominant, accounting for 60% of positive samples. Direct method allowed the isolation of 13 L. pneumophila only of 50 samples (26%), whereas co-culture using a panel of three free living amoeba allowed the isolation of 119 Legionella species from the same samples (80%) CONCLUSIONS: Amoeba co-culture allowed the isolation of several Legionella sp., while direct culture allowed the isolation of L. pneumophila only. Remarkably, Legionella longbeachae, usually isolated from soil and compost, was isolated for the first time in thermal water in three samples using Vermamoeba vermiformis co-culture. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of Legionella in the water of hot springs in Algeria, which are mainly frequented by individuals at risk of Legionellosis, requires urgent control measures.


Assuntos
Fontes Termais/microbiologia , Legionella/isolamento & purificação , Argélia , Amoeba/classificação , Amoeba/genética , Amoeba/isolamento & purificação , Fontes Termais/parasitologia , Legionella/classificação , Legionella/genética , Legionella/crescimento & desenvolvimento , Microbiologia da Água
16.
Syst Appl Microbiol ; 44(1): 126157, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33220635

RESUMO

A novel aerobic moderately thermophilic bacterium, designated strain 2918T, was isolated from a terrestrial hot spring of Kamchatka, Russian Federation. Gram-negative, motile, spherical cells were present singly, in pairs, or aggregates, and reproduced by budding. The strain grew at 25-60°C and within a pH range of 5.0-8.0 with an optimum at 54-60°C and pH 7.5. Strain 2918T did not require sodium chloride or yeast extract for growth. It was a chemoorganoheterotroph, growing on mono-, di- and polysaccharides (starch, lichenan, galactan, arabinan, xanthan gum, beta-glucan). No growth was observed under anaerobic conditions neither in the presence of sulfur, nitrate, or thiosulfate nor without adding any electron acceptor. Major cellular fatty acids were C18:0 and C20:0. The respiratory quinone was MK-6. The size of the genome of strain 2918T was 4.81 Mb. Genomic DNA G+C content was 60.4mol%. According to the 16S rRNA gene sequence and conserved protein sequences phylogenies, strain 2918T represented a distinct lineage of the order Gemmatales within Planctomycetes. Based on phylogenetic analysis and phenotypic features, the novel isolate was assigned to a novel genus in the Gemmatales for which the name Thermogemmata gen. nov. is proposed. Strain 2918T (=KCTC 72012T =VKM B-3161T) represents its first species Thermogemmata fonticola sp. nov.


Assuntos
Bactérias/classificação , Fontes Termais/microbiologia , Filogenia , Bactérias/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , RNA Ribossômico 16S/genética , Federação Russa , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
17.
Artigo em Inglês | MEDLINE | ID: mdl-33295866

RESUMO

A thermoacidophilic, anaerobic, and iron- and sulfur-reducing archaeon, strain NAS-02T, was isolated from a terrestrial hot spring in Japan, as previously reported. This organism is the first non-ammonia-oxidizing isolate in the phylum Thaumarchaeota. Here, we propose Conexivisphaera calida gen. nov., sp. nov. to accommodate this strain. The type strain of the type species is NAS-02T (=JCM 31663T=DSM 105898T). The values of 16S rRNA gene similarity and average amino acid identity between NAS-02T and its closest relatives are <86 and <42 %, respectively. Based on the phylogeny and physiology, we propose the family Conexivisphaeraceae fam. nov., the order Conexivisphaerales ord. nov. and the class Conexivisphaeria class. nov. to accommodate the novel genus.


Assuntos
Archaea/classificação , Fontes Termais/microbiologia , Filogenia , Archaea/isolamento & purificação , Composição de Bases , DNA Arqueal/genética , Ferro/metabolismo , Japão , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Enxofre/metabolismo
18.
Curr Issues Mol Biol ; 40: 25-48, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32159522

RESUMO

Acidophilic microorganisms can thrive in both natural and man-made environments. Natural acidic environments comprise hydrothermal sites on land or in the deep sea, cave systems, acid sulfate soils and acidic fens, as well as naturally exposed ore deposits (gossans). Man-made acidic environments are mostly mine sites including mine waste dumps and tailings, acid mine drainage and biomining operations. The biogeochemical cycles of sulfur and iron, rather than those of carbon and nitrogen, assume centre stage in these environments. Ferrous iron and reduced sulfur compounds originating from geothermal activity or mineral weathering provide energy sources for acidophilic, chemolithotrophic iron- and sulfur-oxidizing bacteria and archaea (including species that are autotrophic, heterotrophic or mixotrophic) and, in contrast to most other types of environments, these are often numerically dominant in acidic sites. Anaerobic growth of acidophiles can occur via the reduction of ferric iron, elemental sulfur or sulfate. While the activities of acidophiles can be harmful to the environment, as in the case of acid mine drainage, they can also be used for the extraction and recovery of metals, as in the case of biomining. Considering the important roles of acidophiles in biogeochemical cycles, pollution and biotechnology, there is a strong need to understanding of their physiology, biochemistry and ecology.


Assuntos
Archaea , Bactérias , Cavernas/microbiologia , Fontes Termais/química , Fontes Termais/microbiologia , Mineração , Solo/química , Sulfatos/metabolismo , Archaea/classificação , Archaea/isolamento & purificação , Archaea/metabolismo , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/metabolismo , Carbono/metabolismo , Concentração de Íons de Hidrogênio , Ferro/metabolismo , Nitrogênio/metabolismo , Oceanos e Mares , Oxirredução
19.
Braz. arch. biol. technol ; 64: e21190020, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1153295

RESUMO

HIGHLIGHTS Screening extremophile Bacillus strains from various Hot Springs Characterization Of Bacillus Strains Producing Highly Thermostable Amylase Genetic identification of the best strains


Abstract Currently thermostable Amylase represents a broad biotechnological interest and desired by a various industries. In this study, forty-six bacterial strains belonging to the genus Bacillus were isolated from various hot springs in the North West of Algeria based on their ability to degrade starch and produce amylase in Starch Agar medium. The majority of isolates showed a positive amylolytic activity. In order to select the most thermostables amylase the effect of temperature on enzymes was estimated, therefore the study of amylase thermostability was culminated by the selection of Four Strains having an interesting optimum of activity and range of stability, reaching 75 °C for the strains HBH1-2, HBH1-3, HBH3-1and 85 °C for the strain HC-2, This indicates that the Enzyme produced by retained strains have optimum activity at high temperature. The identity of the selected strains was established on the basis of the morphological, biochemical characteristics and phylogenetic position as determined by 16S Ribosomal DNA gene sequencing. The whole strains belonged to the genus Bacillus and their phylogeny were also reported in this study.


Assuntos
Bacillus/isolamento & purificação , Bacillus/classificação , Fontes Termais/microbiologia , Amilases , Filogenia , Bacillus/genética , RNA Ribossômico 16S , Argélia , Temperatura Alta
20.
Sci Rep ; 10(1): 21661, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33303863

RESUMO

Using a sample from a terrestrial hot spring (pH 6.8, 60 °C), we enriched a thermophilic microbial consortium performing anaerobic autotrophic oxidation of hydrothermal siderite (FeCO3), with CO2/bicarbonate as the electron acceptor and the only carbon source, producing green rust and acetate. In order to reproduce Proterozoic environmental conditions during the deposition of banded iron formation (BIF), we incubated the microbial consortium in a bioreactor that contained an unmixed anoxic layer of siderite, perfectly mixed N2/CO2-saturated liquid medium and microoxic (2% O2) headspace. Long-term incubation (56 days) led to the formation of magnetite (Fe3O4) instead of green rust as the main product of Fe(II) oxidation, the precipitation of newly formed metabolically induced siderite in the anoxic zone, and the deposition of hematite (Fe2O3) on bioreactor walls over the oxycline boundary. Acetate was the only metabolic product of CO2/bicarbonate reduction. Thus, we have demonstrated the ability of autotrophic thermophilic microbial consortium to perform a short cycle of iron minerals transformation: siderite-magnetite-siderite, accompanied by magnetite and hematite accumulation. This cycle is believed to have driven the evolution of the early biosphere, leading to primary biomass production and deposition of the main iron mineral association of BIF.


Assuntos
Anaerobiose , Processos Autotróficos , Carbonatos/metabolismo , Compostos Férricos/metabolismo , Fontes Termais/microbiologia , Ferro/metabolismo , Consórcios Microbianos/fisiologia , Acetatos/metabolismo , Bicarbonatos/metabolismo , Biomassa , Reatores Biológicos , Dióxido de Carbono/metabolismo , Transporte de Elétrons , Óxido Ferroso-Férrico , Temperatura Alta , Nitrogênio/metabolismo , Oxirredução
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