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1.
Syst Appl Microbiol ; 43(2): 126070, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32081606

RESUMO

In the current Opinion we respond to the major concerns by Bisgaard et al. (2019) and Overmann et al. (2019) and conclude that the adoption of sequences as types for the names of prokaryotes will allow for improvements of the taxonomic framework, increased stability of names derived from robust phylogenomic methods, and enable a full circumscription of the microbial world rather than just the cultivated minority.


Assuntos
Archaea/classificação , Bactérias/classificação , Terminologia como Assunto , Archaea/genética , Archaea/crescimento & desenvolvimento , Archaea/isolamento & purificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , DNA/genética , Genoma/genética , Filogenia
3.
Appl Microbiol Biotechnol ; 103(16): 6783-6795, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31227868

RESUMO

The reject water of anaerobic digestors still contains high levels of methane and ammonium that need to be treated before these effluents can be discharged to surface waters. Simultaneous anaerobic methane and ammonium oxidation performed by nitrate/nitrite-dependent anaerobic methane-oxidizing(N-damo) microorganisms and anaerobic ammonium-oxidizing(anammox) bacteria is considered a potential solution to this challenge. Here, a stable coculture of N-damo archaea, N-damo bacteria, and anammox bacteria was obtained in a sequencing batch reactor fed with methane, ammonium, and nitrite. Nitrite and ammonium removal rates of up to 455 mg N-NO2- L-1 day-1 and 228 mg N-NH4+ L-1 were reached. All nitrate produced by anammox bacteria (57 mg N-NO3- L-1 day-1) was consumed, leading to a nitrogen removal efficiency of 97.5%. In the nitrite and ammonium limited state, N-damo and anammox bacteria each constituted about 30-40% of the culture and were separated as granules and flocs in later stages of the reactor operation. The N-damo archaea increased up to 20% and mainly resided in the granular biomass with their N-damo bacterial counterparts. About 70% of the nitrite in the reactor was removed via the anammox process, and batch assays confirmed that anammox activity in the reactor was close to its maximal potential activity. In contrast, activity of N-damo bacteria was much higher in batch, indicating that these bacteria were performing suboptimally in the sequencing batch reactor, and would probably be outcompeted by anammox bacteria if ammonium was supplied in excess. Together these results indicate that the combination of N-damo and anammox can be implemented for the removal of methane at the expense of nitrite and nitrate in future wastewater treatment systems.


Assuntos
Compostos de Amônio/metabolismo , Archaea/metabolismo , Bactérias Anaeróbias/metabolismo , Reatores Biológicos/microbiologia , Metano/metabolismo , Consórcios Microbianos , Interações Microbianas , Anaerobiose , Archaea/crescimento & desenvolvimento , Bactérias Anaeróbias/crescimento & desenvolvimento , Nitratos/metabolismo , Nitritos/metabolismo , Oxirredução
5.
Appl Microbiol Biotechnol ; 103(15): 6385-6392, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31190238

RESUMO

Nanosized conductive carbon materials have been reported to stimulate methanogenesis by anaerobic microbiomes, while other studies have shown their antimicrobial activities. The present study examined effects of conductive carbon nanoparticles (carbon black Vulcan, CB) on methanogenesis from glucose by anaerobic sludge. We found that a relatively high concentration (e.g., 2% w/v) of CB entirely inhibited the methanogenesis, where a substantial amount of acetate was accumulated after degradation of glucose. Quantitative real-time PCR assays and metabarcoding of 16S rRNA amplicons revealed that, while bacteria were stably present irrespective of the presence and absence of CB, archaea, in particular methanogens, were largely decreased in the presence of CB. Pure-culture experiments showed that methanogenic archaea were more seriously damaged by CB than fermentative bacteria. These results demonstrate that CB specifically inhibits methanogens in anaerobic sludge. We attempted to supplement cathode chambers of microbial electrolysis cells with CB for inhibiting methanogenesis from hydrogen, demonstrating that hydrogen is stably produced in the presence of CB.


Assuntos
Carbono/metabolismo , Eletrólise , Glucose/metabolismo , Metano/metabolismo , Nanopartículas/metabolismo , Esgotos/microbiologia , Anaerobiose , Archaea/classificação , Archaea/crescimento & desenvolvimento , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Carbono/química , Código de Barras de DNA Taxonômico , Metagenômica , Nanopartículas/química
6.
Nat Microbiol ; 4(8): 1401-1410, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31110358

RESUMO

Pili on the surface of Sulfolobus islandicus are used for many functions, and serve as receptors for certain archaeal viruses. The cells grow optimally at pH 3 and ~80 °C, exposing these extracellular appendages to a very harsh environment. The pili, when removed from cells, resist digestion by trypsin or pepsin, and survive boiling in sodium dodecyl sulfate or 5 M guanidine hydrochloride. We used electron cryo-microscopy to determine the structure of these filaments at 4.1 Å resolution. An atomic model was built by combining the electron density map with bioinformatics without previous knowledge of the pilin sequence-an approach that should prove useful for assemblies where all of the components are not known. The atomic structure of the pilus was unusual, with almost one-third of the residues being either threonine or serine, and with many hydrophobic surface residues. While the map showed extra density consistent with glycosylation for only three residues, mass measurements suggested extensive glycosylation. We propose that this extensive glycosylation renders these filaments soluble and provides the remarkable structural stability. We also show that the overall fold of the archaeal pilin is remarkably similar to that of archaeal flagellin, establishing common evolutionary origins.


Assuntos
Archaea/metabolismo , Proteínas de Fímbrias/química , Proteínas de Fímbrias/metabolismo , Archaea/citologia , Archaea/crescimento & desenvolvimento , Proteínas Arqueais/química , Proteínas Arqueais/metabolismo , Proteínas Arqueais/ultraestrutura , Microscopia Crioeletrônica , Proteínas de Fímbrias/ultraestrutura , Glicosilação , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Pepsina A , Conformação Proteica , Estabilidade Proteica , Análise de Sequência de Proteína , Sulfolobus/química , Sulfolobus/citologia , Sulfolobus/metabolismo , Tripsina
7.
mBio ; 10(2)2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30992358

RESUMO

Energy-starved microbes in deep marine sediments subsist at near-zero growth for thousands of years, yet the mechanisms for their subsistence are unknown because no model strains have been cultivated from most of these groups. We investigated Baltic Sea sediments with single-cell genomics, metabolomics, metatranscriptomics, and enzyme assays to identify possible subsistence mechanisms employed by uncultured Atribacteria, Aminicenantes, Actinobacteria group OPB41, Aerophobetes, Chloroflexi, Deltaproteobacteria, Desulfatiglans, Bathyarchaeota, and Euryarchaeota marine group II lineages. Some functions appeared to be shared by multiple lineages, such as trehalose production and NAD+-consuming deacetylation, both of which have been shown to increase cellular life spans in other organisms by stabilizing proteins and nucleic acids, respectively. Other possible subsistence mechanisms differed between lineages, possibly providing them different physiological niches. Enzyme assays and transcripts suggested that Atribacteria and Actinobacteria group OPB41 catabolized sugars, whereas Aminicenantes and Atribacteria catabolized peptides. Metabolite and transcript data suggested that Atribacteria utilized allantoin, possibly as an energetic substrate or chemical protectant, and also possessed energy-efficient sodium pumps. Atribacteria single-cell amplified genomes (SAGs) recruited transcripts for full pathways for the production of all 20 canonical amino acids, and the gene for amino acid exporter YddG was one of their most highly transcribed genes, suggesting that they may benefit from metabolic interdependence with other cells. Subsistence of uncultured phyla in deep subsurface sediments may occur through shared strategies of using chemical protectants for biomolecular stabilization, but also by differentiating into physiological niches and metabolic interdependencies.IMPORTANCE Much of life on Earth exists in a very slow-growing state, with microbes from deeply buried marine sediments representing an extreme example. These environments are like natural laboratories that have run multi-thousand-year experiments that are impossible to perform in a laboratory. We borrowed some techniques that are commonly used in laboratory experiments and applied them to these natural samples to make hypotheses about how these microbes subsist for so long at low activity. We found that some methods for stabilizing proteins and nucleic acids might be used by many members of the community. We also found evidence for niche differentiation strategies, and possibly cross-feeding, suggesting that even though they are barely growing, complex ecological interactions continue to occur over ultralong timescales.


Assuntos
Archaea/classificação , Bactérias/classificação , Sedimentos Geológicos/microbiologia , Metagenoma , Filogenia , Archaea/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Países Bálticos , Deltaproteobacteria/classificação , Deltaproteobacteria/crescimento & desenvolvimento , Ecossistema , Genômica , Oceanos e Mares , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Fatores de Tempo
8.
Bioprocess Biosyst Eng ; 42(7): 1175-1184, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30955092

RESUMO

Microbial community dynamics during the anaerobic co-digestion of pig manure, pasteurized slaughterhouse waste and glycerin were studied in a lab-scale CSTR. The feed composition was optimized through progressive co-substrate additions for enhanced methane production and organic matter removal without accumulation of intermediate compounds. Microbial community structure of biomass samples was studied by means of qPCR and DGGE profiling of 16S rRNA genes (Bacteria and Archaea), and genus-specific qPCR of the methyl coenzyme M reductase gene (mcrA), which encodes for an enzyme universally involved in methanogenesis. The composition of the dominant bacterial populations remained relatively stable, when compared to those in the influent, but the highest changes were observed upon the introduction of glycerin. Biodiversity of archaea was restricted to a few representatives of the genera Methanosaeta and Methanosarcina, but Methanospirillum sp. was detected only when glycerin was introduced in the feeding. Glycerin supplementation coincided with the strongest increase in methane yield (from 0.22 to 0.64 m3CH4 m-3 d-1).


Assuntos
Matadouros , Archaea/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Glicerol/farmacologia , Consórcios Microbianos/efeitos dos fármacos , Eliminação de Resíduos Líquidos , Anaerobiose/efeitos dos fármacos , Animais , Esterco/microbiologia , Suínos
9.
PLoS One ; 14(4): e0206777, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30939175

RESUMO

A chronosequence approach, i.e., a comparison of spatially distinct plots with different stages of succession, is commonly used for studying microbial community dynamics during paedogenesis. The successional traits of prokaryotic communities following sand fixation processes have previously been characterized for arid and semi-arid regions, but they have not been considered for the tundra zone, where the environmental conditions are unfavourable for the establishment of complicated biocoenoses. In this research, we characterized the prokaryotic diversity and abundance of microbial genes found in a typical tundra and wooded tundra along a gradient of increasing vegetation-unfixed aeolian sand, semi-fixed surfaces with mosses and lichens, and mature soil under fully developed plant cover. Microbial communities from typical tundra and wooded tundra plots at three stages of sand fixation were compared using quantitative polymerase chain reaction (qPCR) and high-throughput sequencing of 16S rRNA gene libraries. The abundances of ribosomal genes increased gradually in both chronosequences, and a similar trend was observed for the functional genes related to the nitrogen cycle (nifH, bacterial amoA, nirK and nirS). The relative abundance of Planctomycetes increased, while those of Thaumarchaeota, Cyanobacteria and Chloroflexi decreased from unfixed sands to mature soils. According to ß-diversity analysis, prokaryotic communities of unfixed sands were more heterogeneous compared to those of mature soils. Despite the differences in the plant cover of the two mature soils, the structural compositions of the prokaryotic communities were shaped in the same way. Thus, sand fixation in the tundra zone increases archaeal, bacterial and fungal abundances, shifts and unifies prokaryotic communities structure.


Assuntos
Archaea , Bactérias , Areia/microbiologia , Microbiologia do Solo , Tundra , Archaea/classificação , Archaea/genética , Archaea/crescimento & desenvolvimento , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento
10.
Nat Microbiol ; 4(4): 603-613, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30833729

RESUMO

Methanogenesis is an ancient metabolism of key ecological relevance, with direct impact on the evolution of Earth's climate. Recent results suggest that the diversity of methane metabolisms and their derivations have probably been vastly underestimated. Here, by probing thousands of publicly available metagenomes for homologues of methyl-coenzyme M reductase complex (MCR), we have obtained ten metagenome-assembled genomes (MAGs) belonging to potential methanogenic, anaerobic methanotrophic and short-chain alkane-oxidizing archaea. Five of these MAGs represent under-sampled (Verstraetearchaeota, Methanonatronarchaeia, ANME-1 and GoM-Arc1) or previously genomically undescribed (ANME-2c) archaeal lineages. The remaining five MAGs correspond to lineages that are only distantly related to previously known methanogens and span the entire archaeal phylogeny. Comprehensive comparative annotation substantially expands the metabolic diversity and energy conservation systems of MCR-bearing archaea. It also suggests the potential existence of a yet uncharacterized type of methanogenesis linked to short-chain alkane/fatty acid oxidation in a previously undescribed class of archaea ('Candidatus Methanoliparia'). We redefine a common core of marker genes specific to methanogenic, anaerobic methanotrophic and short-chain alkane-oxidizing archaea, and propose a possible scenario for the evolutionary and functional transitions that led to the emergence of such metabolic diversity.


Assuntos
Alcanos/química , Archaea/metabolismo , Biodiversidade , Metano/metabolismo , Alcanos/metabolismo , Archaea/classificação , Archaea/genética , Archaea/crescimento & desenvolvimento , DNA Arqueal , Metagenoma , Metano/química , Oxirredução , Filogenia
11.
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
12.
J Basic Microbiol ; 59(4): 425-436, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30624810

RESUMO

Ammonia oxidation, mainly driven by ammonia-oxidizing archaea (AOA) and bacteria (AOB), plays an important role in determining the rate of nitrification in riparian zones. However, the underlying factors driving the distribution and activity of AOA and AOB in riparian zones, especially in the rhizosphere of Phragmites communis remain unknown. This study revealed the dominance of AOA in ammonium oxidization with higher abundance and activity in both rhizosphere and bulk soil in summer and winter over AOB in riparian zones, based on molecular methods and double-inhibitors method. Phylogenetic analysis showed that 54d9 cluster and Nitrososphaera dominated the AOA community and Nitrosospira dominated the AOB, respectively. For the distribution of AOA and AOB, it was the spatial heterogeneity of physicochemical properties that had the most significant effect. Specifically, TOM & TC were the main physicochemical variables accounting for the difference in abundance and community composition of AOA, and TN had an important influence on AOB in the sediment/soil in riparian zones. For abundance and activity, seasonal heterogeneity and P. communis rhizosphere had a significant impact on the archaeal activity and abundance, respectively, but did not show significant influencing on AOB. These findings suggest that the small-scale environmental heterogeneities in riparian zones are important in shaping the community composition and abundance of AOA and AOB.


Assuntos
Amônia/metabolismo , Archaea/classificação , Bactérias/classificação , Poaceae , Rizosfera , Microbiologia do Solo , Archaea/genética , Archaea/crescimento & desenvolvimento , Archaea/metabolismo , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Ecossistema , Genes Arqueais/genética , Genes Bacterianos/genética , Sedimentos Geológicos/microbiologia , Nitrificação/genética , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Estações do Ano
13.
Anaerobe ; 56: 8-16, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30633970

RESUMO

To investigate whether there is a nexus between the microbial diversity level (taxonomic, functional and ecological) and the stress tolerance potential of the microbial community, the impact of different ammonium sources was evaluated. Therefore reactors adapted either to the anaerobic digestions of sugar beet silage or maize silage (SBS/MS) were supplemented with animal manure (M) or ammonium carbonate (A). The results showed that increasing concentrations of total ammonium nitrogen (TAN) were not the only reason for community changes: the bacterial community in the reactors given animal manure became more similar over time compared to the reactors given ammonium carbonate. However, this study revealed that a bacterial community with a few dominant members led to a functional more flexible archaeal community (SBS reactors) which was more stress resistant under the experimental conditions. This indicates that a higher functional diversity within a certain part of the community, in the present study the archaeal community, is one important factor for process stability due to a higher tolerance to increasing amounts of process-inhibiting metabolites such as TAN. Compared to this a bacterial community with higher amount of more evenly distributed community members combined with a more rigid archaeal community (MS reactors) showed a lower stress tolerance potential. Moreover it was observed that the disappearance of members of the phylum Cloacimonetes can be used as an indicator for an upcoming process disturbance due to increasing TAN concentrations.


Assuntos
Compostos de Amônio/metabolismo , Archaea/metabolismo , Bactérias/metabolismo , Biocombustíveis/microbiologia , Biota , Esterco/microbiologia , Estresse Fisiológico , Anaerobiose , Animais , Archaea/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Beta vulgaris/metabolismo , Meios de Cultura/química , Zea mays/metabolismo
14.
ISME J ; 13(3): 632-650, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30323265

RESUMO

Despite the significance of biogenic methane generation in coal beds, there has never been a systematic long-term evaluation of the ecological response to biostimulation for enhanced methanogenesis in situ. Biostimulation tests in a gas-free coal seam were analysed over 1.5 years encompassing methane production, cell abundance, planktonic and surface associated community composition and chemical parameters of the coal formation water. Evidence is presented that sulfate reducing bacteria are energy limited whilst methanogenic archaea are nutrient limited. Methane production was highest in a nutrient amended well after an oxic preincubation phase to enhance coal biofragmentation (calcium peroxide amendment). Compound-specific isotope analyses indicated the predominance of acetoclastic methanogenesis. Acetoclastic methanogenic archaea of the Methanosaeta and Methanosarcina genera increased with methane concentration. Acetate was the main precursor for methanogenesis, however more acetate was consumed than methane produced in an acetate amended well. DNA stable isotope probing showed incorporation of 13C-labelled acetate into methanogenic archaea, Geobacter species and sulfate reducing bacteria. Community characterisation of coal surfaces confirmed that methanogenic archaea make up a substantial proportion of coal associated biofilm communities. Ultimately, methane production from a gas-free subbituminous coal seam was stimulated despite high concentrations of sulfate and sulfate-reducing bacteria in the coal formation water. These findings provide a new conceptual framework for understanding the coal reservoir biosphere.


Assuntos
Archaea/metabolismo , Geobacter/metabolismo , Metano/metabolismo , Microbiota , Bactérias Redutoras de Enxofre/metabolismo , Acetatos/análise , Acetatos/metabolismo , Archaea/genética , Archaea/crescimento & desenvolvimento , Isótopos de Carbono/análise , Carvão Mineral/microbiologia , Geobacter/genética , Geobacter/crescimento & desenvolvimento , Metano/análise , Methanosarcina/genética , Methanosarcina/crescimento & desenvolvimento , Methanosarcina/metabolismo , Methanosarcinaceae/genética , Methanosarcinaceae/crescimento & desenvolvimento , Methanosarcinaceae/metabolismo , Campos de Petróleo e Gás , Sulfatos/análise , Sulfatos/metabolismo , Bactérias Redutoras de Enxofre/genética , Bactérias Redutoras de Enxofre/crescimento & desenvolvimento
15.
Environ Microbiol ; 21(1): 18-33, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30136386

RESUMO

Marine oil spills are catastrophic events that cause massive damage to ecosystems at all trophic levels. While most of the research has focused on carbon-degrading microorganisms, the potential impacts of hydrocarbons on microbes responsible for nitrification have received far less attention. Nitrifiers are sensitive to hydrocarbon toxicity: ammonia-oxidizing bacteria and archaea being 100 and 1000 times more sensitive than typical heterotrophs respectively. Field studies have demonstrated the response of nitrifiers to hydrocarbons is highly variable and the loss of nitrification activity in coastal ecosystems can be restored within 1-2 years, which is much shorter than the typical recovery time of whole ecosystems (e.g., up to 20 years). Since the denitrification process is mainly driven by heterotrophs, which are more resistant to hydrocarbon toxicity than nitrifiers, the inhibition of nitrification may slow down the nitrogen turnover and increase ammonia availability, which supports the growth of oil-degrading heterotrophs and possibly various phototrophs. A better understanding of the ecological response of nitrification is paramount in predicting impacts of oil spills on the nitrogen cycle under oil spill conditions, and in improving current bioremediation practices.


Assuntos
Archaea/metabolismo , Bactérias/metabolismo , Ecossistema , Ciclo do Nitrogênio , Poluição por Petróleo , Archaea/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Desnitrificação , Hidrocarbonetos/metabolismo , Oxirredução , Poluição por Petróleo/análise
17.
Archaea ; 2018: 9319345, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30410420

RESUMO

Microorganisms play important roles in the reduction of organic and inorganic pollutants in constructed wetlands used for the treatment of wastewater. However, the diversity and structure of microbial community in constructed wetland system remain poorly known. In this study, the Illumina MiSeq Sequencing of 16S rDNA was used to analyze the bacterial and archaeal microbial community structures of soil and water in a free surface flow constructed wetland, and the differences of bacterial communities and archaeal compositions between soil and water were compared. The results showed that the Proteobacteria were the dominant bacteria, making up 35.38%~48.66% relative abundance. Euryarchaeotic were the absolute dominant archaea in the influent sample with the relative abundance of 93.29%, while Thaumarchaeota showed dominance in the other three samples, making up 50.58%~75.70%. The relative abundances of different species showed great changes in bacteria and archaea, and the number of dominant species in bacteria was much higher than that in archaea. Compared to archaea, the community compositions of bacteria were more abundant and the changes were more significant. Meanwhile, bacteria and archaea had large differences in compositions between water and soil. The microbial richness in water was significantly higher than that in soil. Simultaneously, soil had a significant enrichment effect on some microbial flora.


Assuntos
Archaea/classificação , Archaea/isolamento & purificação , Bactérias/classificação , Bactérias/isolamento & purificação , Águas Residuárias/microbiologia , Purificação da Água/métodos , Áreas Alagadas , Archaea/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Biota , Análise por Conglomerados , DNA Arqueal/química , DNA Arqueal/genética , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Filogenia , Dinâmica Populacional , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
18.
Archaea ; 2018: 8429145, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30302054

RESUMO

An increase in the number of publications in recent years indicates that besides ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA) may play an important role in nitrogen removal from wastewater, gaining wide attention in the wastewater engineering field. This paper reviews the current knowledge on AOA and AOB involved in wastewater treatment systems and summarises the environmental factors affecting AOA and AOB. Current findings reveal that AOA have stronger environmental adaptability compared with AOB under extreme environmental conditions (such as low temperature and low oxygen level). However, there is still little information on the cooperation and competition relationship between AOA and AOB, and other microbes related to nitrogen removal, which needs further exploration. Furthermore, future studies are proposed to develop novel nitrogen removal processes dominated by AOA by parameter optimization.


Assuntos
Amônia/metabolismo , Archaea/metabolismo , Bactérias/metabolismo , Interações Microbianas , Nitrogênio/metabolismo , Águas Residuárias/microbiologia , Archaea/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Oxirredução , Purificação da Água/métodos
19.
Sci Rep ; 8(1): 15671, 2018 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-30353134

RESUMO

Ice entrenched microcosm represents a vast reservoir of novel species and a proxy for past climate reconstitution. Among glacial ecosystems, ice caves represent one of the scarcely investigated frozen habitats. To characterize the microbial diversity of perennial ice from karst ecosystems, Roche 454 sequencing of 16S rRNA gene amplicons from the underground ice block of Scarisoara Ice Cave (Romania) was applied. The temporal distribution of bacterial and archaeal community structures from newly formed, 400, and 900 years old ice layers was surveyed and analyzed in relation with the age and geochemical composition of the ice substrate. The microbial content of cave ice layers varied from 3.3 104 up to 7.5 105 cells mL-1, with 59-78% viability. Pyrosequencing generated 273,102 reads for the five triplicate ice samples, which corresponded to 3,464 operational taxonomic units (OTUs). The distribution of the bacterial phyla in the perennial cave ice varied with age, organic content, and light exposure. Proteobacteria dominated the 1 and 900 years old organic rich ice deposits, while Actinobacteria was mostly found in 900 years old ice strata, and Firmicutes was best represented in 400 years old ice. Cyanobacteria and Chlorobi representatives were identified mainly from the ice block surface samples exposed to sunlight. Archaea was observed only in older ice strata, with a high incidence of Crenarchaeota and Thaumarchaeaota in the 400 years old ice, while Euryarchaeota dominated the 900 years old ice layers, with Methanomicrobia representing the predominant taxa. A large percentage (55.7%) of 16S rRNA gene amplicons corresponded to unidentified OTUs at genus or higher taxa levels, suggesting a greater undiscovered bacterial diversity in this glacial underground habitat. The prokaryotes distribution across the cave ice block revealed the presence of 99 phylotypes specific for different ice layers, in addition to the shared microbial community. Ice geochemistry represented an important factor that explained the microbial taxa distribution in the cave ice block, while the total organic carbon content had a direct impact on the cell density of the ice microcosm. Both bacterial and archaeal community structures appeared to be affected by climate variations during the ice formation, highlighting the cave ice microbiome as a source of putative paleoclimatic biomarkers. This report constitutes the first high-throughput sequencing study of the cave ice microbiome and its distribution across the perennial underground glacier of an alpine ice cave.


Assuntos
Archaea/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Cavernas/microbiologia , Gelo , Archaea/classificação , Bactérias/classificação , Contagem de Colônia Microbiana , Filogenia , Análise de Componente Principal , Células Procarióticas/metabolismo
20.
FEMS Microbiol Ecol ; 94(12)2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30304402

RESUMO

Climate change is causing rapid changes in reef structure, biodiversity, and function, though most sponges are predicted to tolerate conditions projected for 2100. Sponges maintain intimate relationships with microbial symbionts, with previous studies suggesting that microbial flexibility may be pivotal to success under ocean acidification (OA). We performed a reciprocal transplantation of the coral reef sponges Coelocarteria singaporensis and Stylissa cf. flabelliformis between a control reef site and an adjacent CO2 vent site in Papua New Guinea to explore how the sponge microbiome responds to OA. Microbial communities of C. singaporensis, which differed initially between sites, did not shift towards characteristic control or vent microbiomes, even though relative abundances of Chloroflexi and Cyanobacteria increased and that of Thaumarchaeota decreased 7 months after transplantation to the control site. Microbial communities of S. cf. flabelliformis, which were initially stable between sites, did not respond specifically to transplantation but collectively exhibited a significant change over time, with a relative increase in Thaumarchaeota and decrease in Proteobacteria in all treatment groups. The lack of a community shift upon transplantation to the vent site suggests that microbial flexibility, at least in the adult life-history stage, does not necessarily underpin host survival under OA .


Assuntos
Archaea/crescimento & desenvolvimento , Chloroflexi/crescimento & desenvolvimento , Mudança Climática , Cianobactérias/crescimento & desenvolvimento , Microbiota/fisiologia , Poríferos/microbiologia , Proteobactérias/crescimento & desenvolvimento , Água do Mar/química , Animais , Biodiversidade , Dióxido de Carbono/análise , Recifes de Corais , Oceanos e Mares , Papua Nova Guiné , Água do Mar/microbiologia
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