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Microorganisms in Antarctica are recognized for having crucial roles in ecosystems functioning and biogeochemical cycles. To explore the diversity and composition of microbial communities through different terrestrial and marine Antarctic habitats, we analyze 16S rRNA sequence datasets from fumarole and marine sediments, soil, snow and seawater environments. We obtained measures of alpha- and beta-diversities, as well as we have identified the core microbiome and the indicator microbial taxa of a particular habitat. Our results showed a unique microbial community structure according to each habitat, including specific taxa composing each microbiome. Marine sediments harbored the highest microbial diversity among the analyzed habitats. In the fumarole sediments, the core microbiome was composed mainly of thermophiles and hyperthermophilic Archaea, while in the majority of soil samples Archaea was absent. In the seawater samples, the core microbiome was mainly composed by cultured and uncultured orders usually identified on Antarctic pelagic ecosystems. Snow samples exhibited common taxa previously described for habitats of the Antarctic Peninsula, which suggests long-distance dispersal processes occurring from the Peninsula to the Continent. This study contributes as a baseline for further efforts on evaluating the microbial responses to environmental conditions and future changes.
Assuntos
Bactérias , Microbiota , Bactérias/genética , Regiões Antárticas , RNA Ribossômico 16S/genética , Archaea/genética , Microbiota/genética , SoloRESUMO
Microbial communities play a key role in the ocean, acting as primary producers, nutrient recyclers, and energy providers. The São Paulo Plateau is a region located on the southeastern coast of Brazil within economic importance, due to its oil and gas reservoirs. With this focus, this study examined the diversity and composition of microbial communities in marine sediments located at three oceanographic stations in the southern region of São Paulo Plateau using the HOV Shinkai 6500 in 2013. The 16S rRNA gene was sequenced using the universal primers (515F and 926R) by the Illumina Miseq platform. The taxonomic compositions of samples recovered from SP3 station were markedly distinct from those obtained from SP1 and SP2. Although all three stations exhibited a high abundance of Gammaproteobacteria (> 15%), this taxon dominated more than 90% of composition of the A and C sediment layers at SP3. The highest abundance of the archaeal class Nitrososphaeria was presented at SP1, mainly at layer C (~ 21%), being absent at SP3 station. The prediction of chemoheterotrophy and fermentation as important microbial functions was supported by the data. Additionally, other metabolic pathways related to the cycles of nitrogen, carbon and sulfur were also predicted. The core microbiome analysis comprised only two ASVs. Our study contributes to a better understanding of microbial communities in an economically important little-explored region. This is the third microbiological survey in plateau sediments and the first focused on the southern region.
Assuntos
Sedimentos Geológicos , Microbiota , Sedimentos Geológicos/microbiologia , RNA Ribossômico 16S/genética , Brasil , Archaea/genética , Microbiota/genética , Oceano AtlânticoRESUMO
Mining of deep-sea Fe-Mn deposits will remove crusts and nodules from the seafloor. The growth of these minerals takes millions of years, yet little is known about their microbiome. Besides being key elements of the biogeochemical cycles and essential links of food and energy to deep-sea, microbes have been identified to affect manganese oxide formation. In this study, we determined the composition and diversity of Bacteria and Archaea in deep-sea Fe-Mn crusts, nodules, and associated sediments from two areas in the Atlantic Ocean, the Tropic Seamount and the Rio Grande Rise. Samples were collected using ROV and dredge in 2016 and 2018 oceanographic campaigns, and the 16S rRNA gene was sequenced using Illumina platform. Additionally, we compared our results with microbiome data of Fe-Mn crusts, nodules, and sediments from Clarion-Clipperton Zone and Takuyo-Daigo Seamount in the Pacific Ocean. We found that Atlantic seamounts harbor an unusual and unknown Fe-Mn deposit microbiome with lower diversity and richness compared to Pacific areas. Crusts and nodules from Atlantic seamounts have unique taxa (Alteromonadales, Nitrospira, and Magnetospiraceae) and a higher abundance of potential metal-cycling bacteria, such as Betaproteobacteriales and Pseudomonadales. The microbial beta-diversity from Atlantic seamounts was clearly grouped into microhabitats according to sediments, crusts, nodules, and geochemistry. Despite the time scale of million years for these deposits to grow, a combination of environmental settings played a significant role in shaping the microbiome of crusts and nodules. Our results suggest that microbes of Fe-Mn deposits are key in biogeochemical reactions in deep-sea ecosystems. These findings demonstrate the importance of microbial community analysis in environmental baseline studies for areas within the potential of deep-sea mining.
Assuntos
Sedimentos Geológicos , Microbiota , Archaea , Bactérias , Sedimentos Geológicos/química , Oceano Pacífico , RNA Ribossômico 16S/genéticaRESUMO
Deep-sea carbonate mounds can harbor a wide variety of heterotrophic and chemosynthetic microbial communities, providing biodiversity hotspots among the deep-sea benthic ecosystems. This study examined the bacterial and archaeal diversity and community structure in the water column and sediments associated with a recently described giant carbonate mound named Alpha Crucis Carbonate Ridge (ACCR), located in the Southwestern Atlantic Ocean. Because of the acoustic evidence of gas chimneys from a previous study, we further evaluated the chemosynthetic primary production through in situ-simulated dark carbon fixation rates. Pelagic microbial communities varied significantly with depth, showing a high abundance of photosynthetic groups in surface waters and taxa related to nitrification in intermediate and deep waters. The benthic communities from the top of the ACCR were very similar along with the sediment depth, while those from the base of the ACCR showed a clear stratification pattern, with members in the deep strata mainly related to anoxic and chemosynthetic ecosystems. Dark carbon fixation rates were of the same order of magnitude as those of deep-sea cold seeps and hydrothermal vents. Our study provides the first description of the ACCR microbiome and adds new information to help formulate and implement future conservation and management strategies for vulnerable marine ecosystems.
Assuntos
Fontes Hidrotermais , Microbiota , Archaea/genética , Oceano Atlântico , Biodiversidade , Carbonatos , EcossistemaRESUMO
Active volcanoes in Antarctica have remarkable temperature and geochemical gradients that could select for a wide variety of microbial adaptive mechanisms and metabolic pathways. Deception Island is a stratovolcano flooded by the sea, resulting in contrasting ecosystems such as permanent glaciers and active fumaroles, which creates steep gradients that have been shown to affect microbial diversity. In this study, we used shotgun metagenomics and metagenome-assembled genomes to explore the metabolic potentials and survival strategies of microbial communities along an extreme temperature gradient in fumarole and glacier sediments on Deception Island. We observed that communities from a 98 °C fumarole were significantly enriched in genes related to hyperthermophilic (e.g. reverse gyrase, GroEL/GroES and thermosome) and oxidative stress responses, as well as genes related to sulfate reduction, ammonification and carbon fixation. Communities from <80 °C fumaroles possessed more genes related osmotic, cold- and heat-shock responses, and diverse metabolic potentials, such as those related to sulfur oxidation and denitrification, while glacier communities showed abundant metabolic potentials mainly related to heterotrophy. Through the reconstruction of genomes, we were able to reveal the metabolic potentials and different survival strategies of underrepresented taxonomic groups, especially those related to Nanoarchaeota, Pyrodictiaceae and thermophilic ammonia-oxidizing archaeal lineages.
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Bactérias , Microbiota , Regiões Antárticas , Archaea/genética , Bactérias/genética , Microbiota/genética , TemperaturaRESUMO
Marine plastic pollution is a global concern because of continuous release into the oceans over the last several decades. Although recent studies have made efforts to characterize the so-called plastisphere, or microbial community inhabiting plastic substrates, it is not clear whether the plastisphere is defined as a core community or as a random attachment of microbial cells. Likewise, little is known about the influence of the deep-sea environment on the plastisphere. In our experimental study, we evaluated the microbial colonization on polypropylene pellets and two types of plastic bags: regular high density polyethylene (HDPE) and HDPE with the oxo-biodegradable additive BDA. Gravel was used as control. Samples were deployed at three sites at 3300 m depth in the Southwest Atlantic Ocean and left for microbial colonization for 719 days. For microbial communities analysis, DNA was extracted from the biofilm on plastic and gravel substrates, and then the 16S rRNA was sequenced through the Illumina Miseq platform. Cultivation was performed to isolate strains from the plastic and gravel substrates. Substrate type strongly influenced the microbial composition and structure, while no difference between sites was detected. Although several taxa were shared among plastics, we observed some groups specific for each plastic substrate. These communities comprised taxa previously reported from both epipelagic zones and deep-sea benthic ecosystems. The core microbiome (microbial taxa shared by all plastic substrates) was exclusively composed by low abundance taxa, with some members well-described in the plastisphere and with known plastic-degradation capabilities. Additionally, we obtained bacterial strains that have been previously reported inhabiting plastic substrates and/or degrading hydrocarbon compounds, which corroborates our metabarcoding data and suggests the presence of microbial members potentially active and involved with degradation of these plastics in the deep sea.
Assuntos
Microbiota , Plásticos , Archaea/genética , Oceano Atlântico , RNA Ribossômico 16SRESUMO
Seamounts are often covered with Fe and Mn oxides, known as ferromanganese (Fe-Mn) crusts. Future mining of these crusts is predicted to have significant effects on biodiversity in mined areas. Although microorganisms have been reported on Fe-Mn crusts, little is known about the role of crusts in shaping microbial communities. Here, we investigated microbial communities based on 16S rRNA gene sequences retrieved from Fe-Mn crusts, coral skeleton, calcarenite, and biofilm at crusts of the Rio Grande Rise (RGR). RGR is a prominent topographic feature in the deep southwestern Atlantic Ocean with Fe-Mn crusts. Our results revealed that crust field of the RGR harbors a usual deep-sea microbiome. No differences were observed on microbial community diversity among Fe-Mn substrates. Bacterial and archaeal groups related to oxidation of nitrogen compounds, such as Nitrospirae, Nitrospinae phyla, Candidatus Nitrosopumilus within Thaumarchaeota group, were present on those substrates. Additionally, we detected abundant assemblages belonging to methane oxidation, i.e., Methylomirabilales (NC10) and SAR324 (Deltaproteobacteria). The chemolithoautotrophs associated with ammonia-oxidizing archaea and nitrite-oxidizing bacteria potentially play an important role as primary producers in the Fe-Mn substrates from RGR. These results provide the first insights into the microbial diversity and potential ecological processes in Fe-Mn substrates from the Atlantic Ocean. This may also support draft regulations for deep-sea mining in the region.
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Archaea , Manganês , Archaea/genética , Oceano Atlântico , Sedimentos Geológicos , Ferro , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
Methanotrophic bacteria can use methane as sole carbon and energy source. Its importance in the environment is related to the mitigation of methane emissions from soil and water to the atmosphere. Brazilian mangroves are highly productive, have potential to methane production, and it is inferred that methanotrophic community is of great importance for this ecosystem. The scope of this study was to investigate the functional and taxonomic diversity of methanotrophic bacteria present in the anthropogenic impacted sediments from Bertioga´s mangrove (SP, Brazil). Sediment sample was cultivated with methane and the microbiota actively involved in methane oxidation was identified by DNA-based stable isotope probing (DNA-SIP) using methane as a labeled substrate. After 4 days (96 h) of incubation and consumption of 0.7 mmol of methane, the most active microorganisms were related to methanotrophs Methylomonas and Methylobacter as well as to methylotrophic Methylotenera, indicating a possible association of these bacterial groups within a methane-derived food chain in the Bertioga mangrove. The abundance of genera Methylomonas, able to couple methane oxidation to nitrate reduction, may indicate that under low dissolved oxygen tensions, some aerobic methanotrophs could shift to intraerobic methane oxidation to avoid oxygen starvation.
Assuntos
Metano , Microbiota , Brasil , DNA , Isótopos , Oxirredução , Filogenia , Microbiologia do SoloRESUMO
Here we investigated the diversity of bacterial communities from deep-sea surface sediments under influence of asphalt seeps at the Sao Paulo Plateau using next-generation sequencing method. Sampling was performed at North São Paulo Plateau using the human occupied vehicle Shinkai 6500 and her support vessel Yokosuka. The microbial diversity was studied at two surficial sediment layers (0-1 and 1-4 cm) of five samples collected in cores in water depths ranging from 2456 to 2728 m. Bacterial communities were studied through sequencing of 16S rRNA gene on the Ion Torrent platform and clustered in operational taxonomic units. We observed high diversity of bacterial sediment communities as previously described by other studies. When we considered community composition, the most abundant classes were Alphaproteobacteria (27.7%), Acidimicrobiia (20%), Gammaproteobacteria (11.3%) and Deltaproteobacteria (6.6%). Most abundant OTUs at family level were from two uncultured bacteria from Actinomarinales (5.95%) and Kiloniellaceae (3.17%). The unexpected high abundance of Alphaproteobacteria and Acidimicrobiia in our deep-sea microbial communities may be related to the presence of asphalt seep at North São Paulo Plateau, since these bacterial classes contain bacteria that possess the capability of metabolizing hydrocarbon compounds.
Assuntos
Bactérias/isolamento & purificação , Sedimentos Geológicos/microbiologia , Metagenoma , Microbiota/genética , Água do Mar/microbiologia , Alphaproteobacteria/classificação , Alphaproteobacteria/genética , Alphaproteobacteria/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Biodiversidade , DNA Bacteriano/genética , Deltaproteobacteria/classificação , Deltaproteobacteria/genética , Deltaproteobacteria/isolamento & purificação , Gammaproteobacteria/classificação , Gammaproteobacteria/genética , Gammaproteobacteria/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Hidrocarbonetos/metabolismo , Metagenômica/métodos , RNA Ribossômico 16S/genética , Microbiologia da ÁguaRESUMO
An initial multiple biogeochemical dataset was acquired from the first discovered asphalt seeps in the Brazil margin during deep-sea dive surveys in 2013 using a manned submersible. These surveys were conducted on the outer escarpment of the North São Paulo Plateau. Sediment cores taken from the submersible were processed for pore water and sediment biogeochemistry. The silica concentration, as a chemical geothermometer, showed a steep gradient in the pore water, which indicates the possibility of an active brine system operating in the seepage area. Rare earth elements were used as powerful tracers of chemical processes. Low rare earth element concentrations in both asphalt and Fe-Mn oxyhydroxide-phase sediments suggests that rare earth elements were released during the oil fractionation and biodegradation processes and further depleted under the reducing environment. The main bacterial communities of the sediment were Proteobacteria in the asphalt sites, while at non-asphalt sites, the main bacterial communities of sediment were Firmicutes. Stable carbon and nitrogen isotopes were used to determine the food sources of the heterotrophs, and results suggest that asphalt probably provides a carbon source for these benthic animals. This study may provide useful information to clarify the impact of heavy hydrocarbon seepage on the marine ecosystem.
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Organisms in the Haloferax genus are extreme halophiles that grow in environments with pH values between 4 and 12, and temperatures between 0°C and 60°C. In the present study, a draft of the first Haloferax sp. strain ATB1 genome isolated from the region of Cariri (in Paraíba State, Brazil) is presented.
RESUMO
Methanosarcina mazei is a strictly anaerobic methanogen from the Methanosarcinales order, which is known for its broad catabolic range among methanogens and is widespread throughout diverse environments. The draft genome of the strain presented here was cultivated from sediment samples collected from the Tucuruí hydroelectric power station reservoir.
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Exiguobacterium antarcticum is a psychotropic bacterium isolated for the first time from microbial mats of Lake Fryxell in Antarctica. Many organisms of the genus Exiguobacterium are extremophiles and have properties of biotechnological interest, e.g., the capacity to adapt to cold, which make this genus a target for discovering new enzymes, such as lipases and proteases, in addition to improving our understanding of the mechanisms of adaptation and survival at low temperatures. This study presents the genome of E. antarcticum B7, isolated from a biofilm sample of Ginger Lake on King George Island, Antarctic peninsula.
Assuntos
Bacillales/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Genoma Bacteriano , Análise de Sequência de DNA , Regiões Antárticas , Bacillales/isolamento & purificação , Bacillales/fisiologia , Biofilmes/crescimento & desenvolvimento , Água Doce/microbiologia , Ilhas , Lagos , Dados de Sequência MolecularRESUMO
Alkane monooxygenases (Alk) are the key enzymes for alkane degradation. In order to understand the dispersion and diversity of alk genes in Antarctic marine environments, this study analysed by clone libraries the presence and diversity of alk genes (alkB and alkM) in sediments from Admiralty Bay, King George Island, Peninsula Antarctica. The results show a differential distribution of alk genes between the sites, and the predominant presence of new alk genes, mainly in the pristine site. Sequences presented 53.10-69.60% nucleotide identity and 50.90-73.40% amino acid identity to alkB genes described in Silicibacter pomeroyi, Gordonia sp., Prauserella rugosa, Nocardioides sp., Rhodococcus sp., Nocardia farcinica, Pseudomonas putida, Acidisphaera sp., Alcanivorax borkumensis, and alkM described in Acinetobacter sp. This is the first time that the gene alkM was detected and described in Antarctic marine environments. The presence of a range of previously undescribed alk genes indicates the need for further studies in this environment.
Assuntos
Proteínas de Bactérias/genética , Variação Genética , Sedimentos Geológicos/microbiologia , Oxigenases/genética , Regiões Antárticas , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de AminoácidosRESUMO
The protozoan parasite Cryptosporidium has emerged as one of the most important contaminants of water, causing waterborne outbreaks of gastroenteritis worldwide. To monitor and understand the public health significance of this pathogen in environmental samples, several methods have been developed to isolate and detect Cryptosporidium oocysts. The purpose of this study was to perform the first investigation on the presence of Cryptosporidium spp. oocysts in raw sewage and creek water in the city of São Paulo, Brazil. The oocysts were concentrated by flocculation and membrane filtration. The results showed the occurrence of Cryptosporidium spp. in all wastewater samples analyzed, indicating a possible risk for dissemination of these pathogens in aquatic environment and in the community.
Assuntos
Animais , Águas Residuárias/análise , Cryptosporidium , Gastroenterite , Técnicas In Vitro , Oócitos , Ambiente Aquático , MétodosRESUMO
"Cryptosporidium" is an emergent pathogen that causes profuse diarrhea in humans. Outbreaks of human crypstosporidiosis have implicated water as a possible source of contamination. In this study the presence of "Cryptosporidium" sp. oocysts was investigated as well as the fecal contamination in groundwater for consumption in Itaquaquecetuba - São Paulo. Therefore, it was possible to notice that the septic tanks were located close to the wells, exposing them to the risk of contamination. As a consequence of these results and observations efficient disinfecting practices and groundwater monitoring are recommended.
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Humanos , Criptosporidiose/diagnóstico , Cryptosporidium/patogenicidade , Diarreia/diagnóstico , Técnicas In Vitro , Infecções por Protozoários/diagnóstico , Água Subterrânea , Microbiologia da ÁguaRESUMO
Resumo: O objetivo deste trabalho foi pesquisar a ocorrência de Legionella sp em águas residenciais, de prédios públicos e de ambientes hospitalares e industriais. Foram analisadas sessenta e nove amostras de água procedentes de torres de refrigeraçäo, caldeiras, chuveiros, torneiras, reservatórios e outros pontos específicos de prédios públicos, residências, hospitais e industrias. As amostras foram submetidas à concentraçäo e em seguida aos tratamentos ácido e térmico em paralelo, e entäo foram inoculadas em Agar BCYE com ou sem adiçäo de antibióticos. Amostras näo previamentes tratadas foram também utilizadas. Seis amostras apresentaram um total de dezenove colônias positivas sendo onze confirmadas como Legionella sorogrupo 6 e uma como Legionella bozemanii. Melhores resultados foram obtidos nas amostras sem tratamento. Este trabalho comprova a presença de Legionella em nosso meio e a necesidade do desenvolvimento de métodos simples, rápidos e econômicos para sua detecçäo em programas de vigilância e controle (au)
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Legionella pneumophila , Técnicas In VitroRESUMO
O estudo de autodepuraçäo de um córrego sub-tropical, córrego do Agriäo, afluente do Rio Jacaré-Pepira, S. P., que recebe afluentes de resíduos domésticos e pecuários foi efetuado utilizando-se indicadores biológicos: coliformes totais (CT) e fecais (CF), estreptococos fecais (EF), fungos aquáticos e geofungos. O período de estudo abrangeu duas estiagens e um período de chuvas. Foi observada a influência das condiçöes fisiográficas na auto-depuraçäo do curso d'água. A relaçäo CF/EF possibilitou a caracterizaçäo da origem dos despejos e constatou-se que o número de leveduras, (U.F.C./ml), foi bom indicador de poluiçäo de origem fecal, o que näo ocorreu com bolores aquáticos e terrestres