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1.
Chemosphere ; 263: 127919, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32829221

RESUMO

Column systems were used to evaluate the effectiveness of different bioremediation methods (biostimulation (BS) and bioaugmentation (BA)) in treating sulfolane-contaminated groundwater. Batch test results confirmed that Cupriavidus sp. Y9 (Y9) was the most effective strain for BA. The optimal ratio of added native bacteria to Y9 was 10:3. The BA column adapted to a high sulfolane concentration (150 mg L-1) more rapidly and had higher sulfolane removal efficiency (90%) than did the BS column. The change in the biotoxicity of sulfolane-contaminated groundwater upon bioremediation, according to a Microtox test, revealed decreases in the inhibition of the passing of light by the BS column and BS + BA column of 38% and 63%, respectively. These results reveal that combining BS with BA can reduce the biotoxicity of sulfolane. The column tests confirmed the most effective added bacterium in BA, the operating conditions for high-efficiency bioremediation, and possible problems in its future application. The results provide an important reference for the design of methods for the remediation of contaminated sites.


Assuntos
Biodegradação Ambiental , Água Subterrânea/microbiologia , Tiofenos/metabolismo , Poluentes Químicos da Água/metabolismo , Bactérias/metabolismo , Poluentes do Solo/análise
2.
PLoS One ; 15(8): e0237730, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857799

RESUMO

Freshwater ecosystems play a key role in shaping the global carbon cycle and maintaining the ecological balance that sustains biodiversity worldwide. Surficial water bodies are often interconnected with groundwater, forming a physical continuum, and their interaction has been reported as a crucial driver for organic matter (OM) inputs in groundwater systems. However, despite the growing concerns related to increasing anthropogenic pressure and effects of global change to groundwater environments, our understanding of the dynamics regulating subterranean carbon flows is still sparse. We traced carbon composition and transformations in an arid zone calcrete aquifer using a novel multidisciplinary approach that combined isotopic analyses of dissolved organic carbon (DOC) and inorganic carbon (DIC) (δ13CDOC, δ13CDIC, 14CDOC and 14CDIC) with fluorescence spectroscopy (Chromophoric Dissolved OM (CDOM) characterisation) and metabarcoding analyses (taxonomic and functional genomics on bacterial 16S rRNA). To compare dynamics linked to potential aquifer recharge processes, water samples were collected from two boreholes under contrasting rainfall: low rainfall ((LR), dry season) and high rainfall ((HR), wet season). Our isotopic results indicate limited changes and dominance of modern terrestrial carbon in the upper part (northeast) of the bore field, but correlation between HR and increased old and 13C-enriched DOC in the lower area (southwest). CDOM results show a shift from terrestrially to microbially derived compounds after rainfall in the same lower field bore, which was also sampled for microbial genetics. Functional genomic results showed increased genes coding for degradative pathways-dominated by those related to aromatic compound metabolisms-during HR. Our results indicate that rainfall leads to different responses in different parts of the bore field, with an increase in old carbon sources and microbial processing in the lower part of the field. We hypothesise that this may be due to increasing salinity, either due to mobilisation of Cl- from the soil, or infiltration from the downstream salt lake during HR. This study is the first to use a multi-technique assessment using stable and radioactive isotopes together with functional genomics to probe the principal organic biogeochemical pathways regulating an arid zone calcrete system. Further investigations involving extensive sampling from diverse groundwater ecosystems will allow better understanding of the microbiological pathways sustaining the ecological functioning of subterranean biota.


Assuntos
Ciclo do Carbono , Isótopos de Carbono/análise , Monitoramento Ambiental/métodos , Água Subterrânea/química , Microbiota/fisiologia , Solo/química , Austrália , Isótopos de Carbono/metabolismo , Código de Barras de DNA Taxonômico , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Água Subterrânea/microbiologia , RNA Ribossômico 16S/genética , Chuva , Salinidade , Microbiologia do Solo , Espectrometria de Fluorescência
3.
Int J Syst Evol Microbiol ; 70(8): 4739-4747, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32730198

RESUMO

A novel, obligately anaerobic bacterium (strain SURF-ANA1T) was isolated from deep continental subsurface fluids at a depth of 1500 m below surface in the former Homestake Gold Mine (now Sanford Underground Research Facility, in Lead, South Dakota, USA). Cells of strain SURF-ANA1T were Gram-negative, helical, non-spore-forming and were 0.25-0.55×5.0-75.0 µm with a wavelength of 0.5-0.62 µm. Strain SURF-ANA1T grew at 15-50 °C (optimally at 40 °C), at pH 4.8-9.0 (pH 7.2) and in 1.0-40.0 g l-1 NaCl (10 g l-1 NaCl). The strain grew chemoheterotrophically with hydrogen or mono-, di- and polysaccharides as electron donors. The major cellular fatty acids in order of decreasing abundance (comprising >5% of total) were 10-methyl C16:0, iso-C15:0, C18:2 and C18:0 dimethyl acetal (DMA) and C20:0 methylene-nonadecanoic acid. Phylogenetic analysis based on the 16S rRNA gene sequence of strain SURF-ANA1T indicated a closest relationship with the recently characterized Rectinema cohabitans (99%). Despite high sequence identity, because of its distinct physiology, morphology and fatty acid profile, strain SURF-ANA1T is considered to represent a novel species within the genus Rectinema, for which the name Rectinema subterraneum sp. nov. is proposed. To our knowledge, this is the first report of an isolate within the phylum Spirochaetes from the deep (>100 m) terrestrial subsurface. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene and genomic sequences of strain SURF-ANA1T are KU359248 and GCF 009768935.1, respectively. The type strain of Rectinema subterraneum is SURF-ANA1T (=ATCC TSD-67=JCM 32656).


Assuntos
Água Subterrânea/microbiologia , Filogenia , Spirochaetaceae/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , South Dakota , Spirochaetaceae/isolamento & purificação
4.
Environ Geochem Health ; 42(11): 3819-3839, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32601907

RESUMO

Monitoring the groundwater chemical composition and identifying the presence of pollutants is an integral part of any comprehensive groundwater management strategy. The present study was conducted in a part of West Tripura, northeast India, to investigate the presence and sources of trace metals in groundwater and the risk to human health due to direct ingestion of groundwater. Samples were collected from 68 locations twice a year from 2016 to 2018. Mixed Ca-Mg-HCO3, Ca-Cl and Ca-Mg-Cl were the main groundwater types. Hydrogeochemical methods showed groundwater mineralization due to (1) carbonate dissolution, (2) silicate weathering, (3) cation exchange processes and (4) anthropogenic sources. Occurrence of faecal coliforms increased in groundwater after monsoons. Nitrate and microbial contamination from wastewater infiltration were apparent. Iron, manganese, lead, cadmium and arsenic were above the drinking water limits prescribed by the Bureau of Indian Standards. Water quality index indicated 1.5% had poor, 8.7% had marginal, 16.2% had fair, 66.2% had good and 7.4% had excellent water quality. Correlation and principal component analysis reiterated the sources of major ions and trace metals identified from hydrogeochemical methods. Human exposure assessment suggests health risk due to high iron in groundwater. The presence of unsafe levels of trace metals in groundwater requires proper treatment measures before domestic use.


Assuntos
Água Subterrânea/análise , Metais/análise , Oligoelementos/análise , Poluentes Químicos da Água/análise , Qualidade da Água , Carbonatos/análise , Carbonatos/química , Exposição Dietética/efeitos adversos , Exposição Dietética/análise , Água Potável/análise , Monitoramento Ambiental/métodos , Fezes/microbiologia , Água Subterrânea/química , Água Subterrânea/microbiologia , Humanos , Hidrologia/métodos , Índia , Nitratos/análise , Medição de Risco/métodos , Águas Residuárias/análise , Águas Residuárias/microbiologia , Microbiologia da Água
5.
PLoS One ; 15(6): e0235235, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32598345

RESUMO

Mobile Bay, the fourth largest estuary in the USA located in the northern Gulf of Mexico, is known for extreme hypoxia in the water column during dry season caused by NH4+-rich and anoxic submarine groundwater discharge (SGD). Nutrient dynamics in the coastal ecosystem point to potentially elevated microbial activities; however, little is known about microbial community composition and their functional roles in this area. In this study, we investigated microbial community composition, distribution, and metabolic prediction along the coastal hydrological compartment of Mobile Bay using 16S rRNA gene sequencing. We collected microbial samples from surface (river and bay water) and subsurface water (groundwater and coastal pore water from two SGD sites with peat and sandy lithology, respectively). Salinity was identified as the primary factor affecting the distribution of microbial communities across surface water samples, while DON and PO43- were the major predictor of community shift within subsurface water samples. Higher microbial diversity was found in coastal pore water in comparison to surface water samples. Gammaproteobacteria, Bacteroidia, and Oxyphotobacteria dominated the bacterial community. Among the archaea, methanogens were prevalent in the peat-dominated SGD site, while the sandy SGD site was characterized by a higher proportion of ammonia-oxidizing archaea. Cyanobium PCC-6307 and unclassified Thermodesulfovibrionia were identified as dominant taxa strongly associated with trends in environmental parameters in surface and subsurface samples, respectively. Microbial communities found in the groundwater and peat layer consisted of taxa known for denitrification and dissimilatory nitrate reduction to ammonium (DNRA). This finding suggested that microbial communities might also play a significant role in mediating nitrogen transformation in the SGD flow path and in affecting the chemical composition of SGD discharging to the water column. Given the ecological importance of microorganisms, further studies at higher taxonomic and functional resolution are needed to accurately predict chemical biotransformation processes along the coastal hydrological continuum, which influence water quality and environmental condition in Mobile Bay.


Assuntos
Monitoramento Ambiental/métodos , Água Subterrânea/análise , Água Subterrânea/microbiologia , Microbiota , Água do Mar/análise , Água do Mar/microbiologia , Golfo do México , Hidrologia , RNA Ribossômico 16S/análise , Movimentos da Água
6.
PLoS One ; 15(4): e0232265, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353009

RESUMO

The groundwater biome is a poorly characterized habitat hypothesized to harbor uniquely diverse bacterial communities; the degree to which these communities differ from associated soils is a central question in environmental microbiology. We characterized the Bacterial community composition in 37 aquifer and 32 surface soil samples across the island of O'ahu, Hawai'i. Several bacterial phyla (Acetothermia, Omnitrophica, Parcubacteria, Peregrinibacteria) relatively abundant in the aquifer samples were rare to absent in the soils. Immense bacterial diversity detected in the deep aquifers indicates that these environments are not as homogenous as expected, but provide various niches and energy sources for wide variety of bacteria. A small proportion of OTUs were widespread in all the basal (0.63%) and all the dike aquifer (0.31%) samples. However, these core bacteria comprised an average of 31.8% (ranging 16.2%-62.0%) and 15.4% (0.1%-31.5%) of all sequences isolated from the basal and dike aquifers respectively. Bacterial community composition correlated significantly with the sodium, sulfate, potassium, total dissolved solids, nitrate, conductivity, and pH in the basal aquifers, while phosphate and bicarbonate levels were also highly important when dike water samples were included in the analyses. This was consistent with high relative abundance of putative chemolithoautoroph taxa in the aquifer communities relative to soils. Targeted molecular and culture-based fecal indicator microbial analyses indicated good water quality of aquifers. The dominance of unique, deeply branching lineages in tropical aquifers emphasizes a large adaptive potential in O'ahu's aquifers; variability among groundwater samples suggests that aquifer habitats are surprisingly variable potentially harboring a variety of chemolithotrophic energy sources. Although parallel analyses of conventional and alternative indicators indicated good groundwater quality, this study calls for groundwater monitoring programs which would consider public as well as ecosystem health.


Assuntos
Bactérias/classificação , Água Subterrânea/química , Água Subterrânea/microbiologia , Ecossistema , Monitoramento Ambiental/métodos , Ilhas , Nitratos/química , Filogenia , Sulfatos/química , Microbiologia da Água , Qualidade da Água
7.
Environ Monit Assess ; 192(6): 395, 2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32458070

RESUMO

The current study aimed to assess the quality of apportion pollution sources and examine the impacts of anthropogenic activities on groundwater. The study was implemented in two sequential steps of (1) bulk examination of groundwater quality followed by principal component analysis/factor analysis (PCA/FA) to apportion pollution sources and (2) pollution source-based examination to assess the effects of anthropogenic activities. Well-water samples were taken in Ho Chi Minh City, Vietnam, in 2015 (233 samples) and 2019 (20 samples) and analyzed for 8 and 15 water quality parameters, respectively. The results showed that 99% of studied wells had pH value lower than the permissible limit, and 29, 20, 15, and 14% of studied wells had concentrations of Fe, NH4+, COD (chemical oxygen demand), and coliform, respectively, higher than the maximum permissible limit. PCA/FA revealed that three pollution sources, ranked in the order of importance: agricultural, urban, and industrial activities, could mainly contribute to enriching the pollutant concentrations of groundwater. While agricultural activities may contaminate groundwater with organic substances, the urban area may enrich bacterial-pathogen density such as E. coli and coliform, and the industrial area may contribute to contaminating groundwater with some inorganic parameters. Groundwater quality index and ANOVA showed that groundwater of the studied area was poor to very poor in quality and that in the agricultural area was the worst of the three land-use types. In brief, the groundwater quality in the studied area was degraded and agricultural activities were the most important factor causing the degradation followed by urban and industrial activities.


Assuntos
Monitoramento Ambiental , Água Subterrânea , Análise de Componente Principal , Poluentes Químicos da Água , Cidades , Escherichia coli/fisiologia , Água Subterrânea/microbiologia , Água Subterrânea/normas , Vietnã , Poluentes Químicos da Água/análise
8.
J Environ Public Health ; 2020: 6894805, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32300368

RESUMO

Like several parts in the Middle East, the West Bank is in a significant water scarcity status. Palestinians use groundwater as the main water source, supplying more than 90% of the consumed water in the West Bank. The aim of this study is to enhance the knowledge on drinking water quality in the West Bank. Groundwater quality data was obtained from the Palestinian Water Authority, including the years 2015 and 2016, from the Northern six districts of the West Bank. The water quality data were analyzed and matched with the World Health Organization (WHO) guidelines and the Palestinian standards for drinking water quality. The findings of this study revealed that groundwater in the north of the West Bank comply with several drinking water requirements including total hardness, pH, and sodium and chloride content. Conversely, 18% of the samples exceed the limits for nitrate concentration. The fecal Coliforms and total Coliforms results show that 98.7% of the samples give no risk, but 1.3% of the samples give low risk, and no sample gives intermediate-to-high risks. The microbial and chemical pollution of groundwater is postulated to inadequate wastewater management, high use of fertilizers, and uncontrolled disposal of animal manure. Therefore, it is crucial to disinfect drinking water at the source of production before supply as an immediate action, followed by implementing pollution prevention measures.


Assuntos
Água Subterrânea/análise , Água Subterrânea/microbiologia , Qualidade da Água , Enterobacteriaceae/isolamento & purificação , Fezes/microbiologia , Água Subterrânea/química , Oriente Médio , Água
9.
ISME J ; 14(6): 1547-1560, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32203118

RESUMO

Sediment-hosted CO2-rich aquifers deep below the Colorado Plateau (USA) contain a remarkable diversity of uncultivated microorganisms, including Candidate Phyla Radiation (CPR) bacteria that are putative symbionts unable to synthesize membrane lipids. The origin of organic carbon in these ecosystems is unknown and the source of CPR membrane lipids remains elusive. We collected cells from deep groundwater brought to the surface by eruptions of Crystal Geyser, sequenced the community, and analyzed the whole community lipidome over time. Characteristic stable carbon isotopic compositions of microbial lipids suggest that bacterial and archaeal CO2 fixation ongoing in the deep subsurface provides organic carbon for the complex communities that reside there. Coupled lipidomic-metagenomic analysis indicates that CPR bacteria lack complete lipid biosynthesis pathways but still possess regular lipid membranes. These lipids may therefore originate from other community members, which also adapt to high in situ pressure by increasing fatty acid unsaturation. An unusually high abundance of lysolipids attributed to CPR bacteria may represent an adaptation to membrane curvature stress induced by their small cell sizes. Our findings provide new insights into the carbon cycle in the deep subsurface and suggest the redistribution of lipids into putative symbionts within this community.


Assuntos
Dióxido de Carbono/metabolismo , Água Subterrânea/microbiologia , Archaea/genética , Processos Autotróficos , Bactérias/genética , Carbono/metabolismo , Ciclo do Carbono , Colorado , Ecossistema , Lipídeos/análise , Metagenoma , Filogenia
10.
Sci Rep ; 10(1): 4682, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32170164

RESUMO

Benthic microorganisms transported into the water column potentially influence biogeochemical cycles and the pelagic food web structure. In the present study six gas-releasing vent sites in the Coal Oil Point seep field (California) were investigated, and the dislocation of microorganisms from the sediment into the water column via gas bubbles released from the seabed was documented. It was found that the methanotrophs transport efficiency was dependent on the volumetric gas flow, with the highest transport rate of 22.7 × 103 cells mLgas-1 at a volumetric gas flow of 0.07 mLgas s-1, and the lowest rate of 0.2 × 103 cells mLgas-1 at a gas flow of 2.2 mLgas s-1. A simple budget approach showed that this bubble-mediated transport has the potential to maintain a relevant part of the water-column methanotrophs in the seep field. The bubble-mediated link between the benthic and pelagic environment was further supported by genetic analyses, indicating a transportation of methanotrophs of the family Methylomonaceae and oil degrading bacteria of the genus Cycloclasticus from the sediment into the water column. These findings demonstrate that the bubble-mediated transport of microorganisms influences the pelagic microbial abundance and community composition at gas-releasing seep sites.


Assuntos
Sedimentos Geológicos/microbiologia , Metano , Microbiota , Microbiologia da Água , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Água Subterrânea/análise , Água Subterrânea/química , Água Subterrânea/microbiologia , Metano/química , Metano/metabolismo
11.
J Water Health ; 18(1): 77-90, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32129189

RESUMO

The precariousness of the rural population in Africa is often symbolized by the lack of potable and safe drinking water. This study investigates the physico-chemical and bacteriological characteristics of 32 water samples with respect to WHO standards. The water samples were collected from wells, boreholes and small drinking water supply systems (DWS) in and around the township of Bonkoukou (Niger). The Water Quality Index (WQI) tool was used to assess the overall water quality with different physico-chemical parameters. Where the pH of the samples was acceptable, the samples showed higher levels of mineralization and deoxygenation. Overall, the samples were slightly hard, chlorinated and sulfated but much alkaline and contained nitrate and nitrite ions 2-16 times higher than the WHO standards. The use of WQI shows that samples in the DWS are safe for drinking. Samples coming from wells are the most polluted (58.50%) compared to those taken from boreholes (53.00%), while the percentage of samples from boreholes, unfit for drinking, is higher (41.00%) than that of the samples taken from wells (25.00%). Moreover, water in this area was characterized by the presence of total germs indicating bacteriological pollution. Hence, for the supply of safe drinking water to the larger number of people in such a rural area, the capacity of actual DWS must be improved and widespread.


Assuntos
Monitoramento Ambiental , Água Subterrânea/química , Poluentes Químicos da Água , Água Potável , Água Subterrânea/microbiologia , Humanos , Níger , Qualidade da Água , Abastecimento de Água , Poços de Água
12.
World J Microbiol Biotechnol ; 36(2): 29, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32016527

RESUMO

Short-chain halogenated aliphatic hydrocarbons (e.g. perchloroethene, trichloroethene) are among the most toxic environmental pollutants. Perchloroethene and trichloroethene can be dechlorinated to non-toxic ethene through reductive dechlorination by Dehalococcoides sp. Bioaugmentation, applying cultures containing organohalide-respiring microorganisms, is a possible technique to remediate sites contaminated with chlorinated ethenes. Application of site specific inocula is an efficient alternative solution. Our aim was to develop site specific dechlorinating microbial inocula by enriching microbial consortia from groundwater contaminated with trichloroethene using microcosm experiments containing clay mineral as solid phase. Our main goal was to develop fast and reliable method to produce large amount (100 L) of bioactive agent with anaerobic fermentation technology. Polyphasic approach has been applied to monitor the effectiveness of dechlorination during the transfer process from bench-scale (500 mL) to industrial-scale (100 L). Gas chromatography measurement and T-RFLP (Terminal Restriction Fragment Length Polymorphism) revealed that the serial subculture of the enrichments shortened the time-course of the complete dechlorination of trichloroethene to ethene and altered the composition of bacterial communities. Complete dechlorination was observed in enrichments with significant abundance of Dehalococcoides sp. cultivated at 8 °C. Consortia incubated in fermenters at 18 °C accelerated the conversion of TCE to ethene by 7-14 days. Members of the enrichments belong to the phyla Bacteroidetes, Chloroflexi, Proteobacteria and Firmicutes. According to the operational taxonomic units, main differences between the composition of the enrichment incubated at 8 °C and 18 °C occurred with relative abundance of acetogenic and fermentative species. In addition to the temperature, the site-specific origin of the microbial communities and the solid phase applied during the fermentation technique contributed to the development of a unique microbial composition.


Assuntos
Anaerobiose/fisiologia , Bactérias/metabolismo , Biodegradação Ambiental , Argila/química , Microbiota/fisiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteroidetes/genética , Bacteroidetes/metabolismo , Chloroflexi/genética , Chloroflexi/metabolismo , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Fermentação , Firmicutes/genética , Firmicutes/metabolismo , Geobacter/genética , Geobacter/metabolismo , Água Subterrânea/microbiologia , Consórcios Microbianos , Polimorfismo de Fragmento de Restrição , Proteobactérias/genética , Proteobactérias/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/isolamento & purificação , Tricloroetileno/química , Microbiologia da Água , Poluentes Químicos da Água/metabolismo
13.
Int J Syst Evol Microbiol ; 70(4): 2420-2425, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32100691

RESUMO

Yeast strains belonging to a novel anamorphic yeast species were isolated from subsoil groundwater contaminated with hydrocarbons in a metal working factory located in northern Spain, and from a human infection in the USA. Comparison of ITS sequences between the isolates revealed 0.2 % divergence between the Spanish isolates and 0.46 % divergence between those and the USA isolate. Phylogenetic analysis based on the D1/D2 domains of the LSU rRNA gene showed that these isolates belong to the Wickerhamiella clade with W. sorbophila and W. infanticola as their closest relatives. Sequence divergence between the new isolates and W. sorbophila and W. infanticola was 1.97 and 1.79 %, respectively. The isolates in the novel species are not fermentative and pseudohyphae were not produced. Sexual reproduction was not observed for individual isolates or in mixtures of isolates. Conjugation between the isolates in the novel species and close relatives W. sorbophila and W. infanticola was not observed. These data support the proposal of Wickerhamiella verensis as a novel species, with CECT 12028T as the holotype.


Assuntos
Água Subterrânea/microbiologia , Micoses/microbiologia , Filogenia , Saccharomycetales/classificação , DNA Fúngico/genética , Fermentação , Georgia , Humanos , Hidrocarbonetos , Lactente , Técnicas de Tipagem Micológica , Saccharomycetales/isolamento & purificação , Análise de Sequência de DNA , Espanha , Poluentes Químicos da Água
14.
Chemosphere ; 250: 126210, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32109698

RESUMO

This study utilized innovative analyses to develop multiple lines of evidence for natural attenuation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in groundwater at the U.S. Department of Energy's Pantex Plant. RDX, as well as the degradation product 4-nitro-2,4-diazabutanal (NDAB; produced by aerobic biodegradation or alkaline hydrolysis) were detected in a large portion of the plume, with lower concentrations of the nitroso-containing metabolites produced during anaerobic biodegradation. 16S metagenomic sequencing detected the presence of bacteria known to aerobically degrade RDX (e.g., Gordonia, Rhodococcus) and NDAB (Methylobacterium), as well as the known anoxic RDX degrader Pseudomonas fluorescens I-C. Proteomic analysis detected both the aerobic RDX degradative enzyme XplA, and the anoxic RDX degradative enzyme XenB. Groundwater enrichment cultures supplied with low concentrations of labile carbon confirmed the potential of the extant groundwater community to aerobically degrade RDX and produce NDAB. Compound-specific isotope analysis (CSIA) of RDX collected at the site showed fractionation of nitrogen isotopes with δ15N values ranging from approximately -5‰ to +9‰, providing additional evidence of RDX degradation. Taken together, these results provide evidence of in situ RDX degradation in the Pantex Plant groundwater. Furthermore, they demonstrate the benefit of multiple lines of evidence in supporting natural attenuation assessments, especially with the application of innovative isotopic and -omic technologies.


Assuntos
Biodegradação Ambiental , Água Subterrânea/química , Triazinas/metabolismo , Poluentes Químicos da Água/metabolismo , Substâncias Explosivas/análise , Gordonia (Bactéria)/metabolismo , Água Subterrânea/microbiologia , Isótopos de Nitrogênio/análise , Proteômica , Rhodococcus/metabolismo , Triazinas/análise , Poluentes Químicos da Água/análise
15.
Can J Microbiol ; 66(5): 337-350, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32069070

RESUMO

Shiga-toxin-producing Escherichia coli (STEC) represent a major concern for waterborne disease outbreaks associated with consumption of contaminated groundwater. Over 4 million people rely on private groundwater systems as their primary drinking water source in Canada; many of these systems do not meet current standards for water quality. This manuscript provides a scoping overview of studies examining STEC prevalence and occurrence in groundwater, and it includes a synopsis of the environmental variables affecting survival, transport, persistence, and overall occurrence of these important pathogenic microbes in private groundwater wells used for drinking purposes.


Assuntos
Água Potável/microbiologia , Água Subterrânea/microbiologia , Escherichia coli Shiga Toxigênica/isolamento & purificação , Animais , Canadá , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Proteínas de Escherichia coli/metabolismo , Gastroenterite/microbiologia , Gastroenterite/prevenção & controle , Humanos , Escherichia coli Shiga Toxigênica/metabolismo , Microbiologia da Água
16.
ISME J ; 14(5): 1260-1272, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32047278

RESUMO

The deep terrestrial subsurface remains an environment where there is limited understanding of the extant microbial metabolisms. At Olkiluoto, Finland, a deep geological repository is under construction for the final storage of spent nuclear fuel. It is therefore critical to evaluate the potential impact microbial metabolism, including sulfide generation, could have upon the safety of the repository. We investigated a deep groundwater where sulfate is present, but groundwater geochemistry suggests limited microbial sulfate-reducing activity. Examination of the microbial community at the genome-level revealed microorganisms with the metabolic capacity for both oxidative and reductive sulfur transformations. Deltaproteobacteria are shown to have the genetic capacity for sulfate reduction and possibly sulfur disproportionation, while Rhizobiaceae, Rhodocyclaceae, Sideroxydans, and Sulfurimonas oxidize reduced sulfur compounds. Further examination of the proteome confirmed an active sulfur cycle, serving for microbial energy generation and growth. Our results reveal that this sulfide-poor groundwater harbors an active microbial community of sulfate-reducing and sulfide-oxidizing bacteria, together mediating a sulfur cycle that remained undetected by geochemical monitoring alone. The ability of sulfide-oxidizing bacteria to limit the accumulation of sulfide was further demonstrated in groundwater incubations and highlights a potential sink for sulfide that could be beneficial for geological repository safety.


Assuntos
Água Subterrânea/microbiologia , Enxofre/metabolismo , Bactérias/metabolismo , Finlândia , Microbiota , Oxirredução , Sulfatos/metabolismo , Sulfetos/metabolismo
17.
PLoS One ; 15(1): e0227136, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923233

RESUMO

Antibiotics are administered to livestock in animal feeding operations (AFOs) for the control, prevention, and treatment of disease. Manure from antibiotic treated livestock contains unmetabolized antibiotics that provide selective pressure on bacteria, facilitating the expression of anti-microbial resistance (AMR). Manure application on row crops is an agronomic practice used by growers to meet crop nutrient needs; however, it can be a source of AMR to the soil and water environment. This study in central Iowa aims to directly compare AMR indicators in outlet runoff from two adjacent (221 to 229 ha) manured and non-manured catchments (manure comparison), and among three catchments (600 to 804 ha) with manure influence, no known manure application (control), and urban influences (mixed land use comparison). Monitored AMR indicators included antibiotic resistance genes (ARGs) ermB, ermF (macrolide), tetA, tetM, tetO, tetW (tetracycline), sul1, sul2 (sulfonamide), aadA2 (aminoglycoside), vgaA, and vgaB (pleuromutilin), and tylosin and tetracycline resistant enterococci bacteria. Results of the manure comparison showed significantly higher (p<0.05) tetracycline and tylosin resistant bacteria from the catchment with manure application in 2017, but no differences in 2018, possibly due to changes in antibiotic use resulting from the Veterinary Feed Directive. Moreover, the ARG analysis indicated a larger diversity of ARGs at the manure amended catchment. The mixed land use comparison showed the manure amended catchment had significantly higher (p<0.05) tetracycline resistant bacteria in 2017 and significantly higher tylosin resistant bacteria in 2017 and 2018 than the urban influenced catchment. The urban influenced catchment had significantly higher ermB concentrations in both sampling years, however the manure applied catchment runoff consisted of higher relative abundance of total ARGs. Additionally, both catchments showed higher AMR indicators compared to the control catchment. This study identifies four ARGs that might be specific to AMR as a result of agricultural sources (tetM, tetW, sul1, sul2) and optimal for use in watershed scale monitoring studies for tracking resistance in the environment.


Assuntos
Agricultura , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Água Subterrânea/microbiologia , Esterco/microbiologia , Animais , Enterococcus/genética , Iowa , Gado/microbiologia , Tetraciclina/farmacologia , Tilosina/farmacologia
18.
Environ Geochem Health ; 42(9): 2685-2701, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31912340

RESUMO

Groundwater pollution in tropical and human-altered coastal landscapes is receiving novel attention due to decreasing in annual recharge as a consequence of recurrent droughts and overexploitation, whereby saline intrusion, point and diffuse source contamination, and water conflicts are common denominators. This study presents a detailed groundwater evaluation in a coastal aquifer within the central Pacific coast of Costa Rica. Three sampling campaigns including major ions, heavy metals, and fecal coliform analyses were conducted between July 2013 and March 2014 across 17 wells within the alluvial and fissured units of the Jacó aquifer. The groundwater system is classified as mixed HCO3--Ca2+-Mg2+ type. Coliforms presence was found in two wells, nearby Mona Creek headwaters and near the coastal line. Heavy metal concentrations were below quantification limits in most of the wells; however, chromium concentrations up to 6.56 µg/L were quantified within the coastal line and central portion of the alluvial aquifer in 20 out of the 48 samples. The spatial distribution of major ions (K+, Na+, Ca2+, Mg2+, Cl-, SO42-, and HCO3-) exhibited an increasing trend towards the central portion of the alluvial aquifer, which may be potentially associated with the large unregulated urban expansion, invoking a need of a continuous water quality monitoring program in this touristic hot spot. This study provides useful information for other similar coastal aquifers in Central America, whereby increasing population growth and unregulated touristic, industrial, and agricultural activities are posing a truly challenge to ensure water security and sustainability parallel to the economic development in a changing climate.


Assuntos
Água Subterrânea/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise , Agricultura , Costa Rica , Enterobacteriaceae , Monitoramento Ambiental , Fezes/microbiologia , Água Subterrânea/microbiologia , Humanos , Metais Pesados/análise , Oceano Pacífico , Microbiologia da Água , Qualidade da Água , Poços de Água
19.
Microbes Environ ; 35(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-31932538

RESUMO

Accretionary prisms are thick masses of sedimentary material scraped from the oceanic crust and piled up at convergent plate boundaries found across large regions of the world. Large amounts of anoxic groundwater and natural gas, mainly methane (CH4), are contained in deep aquifers associated with these accretionary prisms. To identify the subsurface environments and potential for CH4 production by the microbial communities in deep aquifers, we performed chemical and microbiological assays on groundwater and natural gas derived from deep aquifers associated with an accretionary prism and its overlying sedimentary layers. Physicochemical analyses of groundwater and natural gas suggested wide variations in the features of the six deep aquifers tested. On the other hand, a stable carbon isotope analysis of dissolved inorganic carbon in the groundwater and CH4 in the natural gas showed that the deep aquifers contained CH4 of biogenic or mixed biogenic and thermogenic origins. Live/dead staining of microbial cells contained in the groundwater revealed that the cell density of live microbial cells was in the order of 104 to 106| |cells| |mL-1, and cell viability ranged between 7.5 and 38.9%. A DNA analysis and anoxic culture of microorganisms in the groundwater suggested a high potential for CH4 production by a syntrophic consortium of hydrogen (H2)-producing fermentative bacteria and H2-utilizing methanogenic archaea. These results suggest that the biodegradation of organic matter in ancient sediments contributes to CH4 production in the deep aquifers associated with this accretionary prism as well as its overlying sedimentary layers.


Assuntos
Sedimentos Geológicos/microbiologia , Água Subterrânea/microbiologia , Metano/biossíntese , Consórcios Microbianos , Anaerobiose , Archaea/classificação , Archaea/genética , Archaea/isolamento & purificação , Archaea/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Carbono/análise , Sedimentos Geológicos/química , Água Subterrânea/química , Hidrogênio/metabolismo , Japão , Metano/análise , Gás Natural/análise , RNA Ribossômico 16S/genética
20.
J Hazard Mater ; 382: 121228, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31561197

RESUMO

Vanadate contaminant in groundwater receives increasing attentions, but little is known on its biogeochemical transformation with gaseous electron donors. This study investigated bio-reduction of vanadate coupled with anaerobic methane oxidation and its relationship with nitrate reduction. Results showed 95.8 ±â€¯3.1% of 1 mM vanadate was removed within 7 days using methane as the sole electron donor. Tetravalent vanadium compounds were the main reduction products, which precipitated naturally in groundwater environment. The introduction of nitrate inhibited vanadate reduction, though both were reduced in parallel. Accumulations of volatile fatty acids (VFAs) were observed from methane oxidation. Preliminary microbial community structure and metabolite analyses indicated that vanadate was likely reduced via Methylomonas coupled with methane oxidation or through synergistic relationships between methane oxidizing bacteria and heterotrophic vanadate reducers with VFAs served as the intermediates.


Assuntos
Água Subterrânea/microbiologia , Metano/metabolismo , Nitratos/metabolismo , Vanadatos/metabolismo , Poluentes Químicos da Água/metabolismo , Anaerobiose , Microbiota , Oxirredução
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