Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 939
Filtrar
1.
PLoS One ; 15(9): e0238808, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32913356

RESUMO

The presence of airborne cyanobacteria and microalgae as well as their negative impacts on human health have been documented by many researchers worldwide. However, studies on cyanobacteria and microalgae are few compared with those on bacteria and viruses. Research is especially lacking on the presence and taxonomic composition of cyanobacteria and microalgae near economically important water bodies with much tourism, such as the Adriatic Sea region. Here, we present the first characterization of the airborne cyanobacteria and microalgae in this area. Sampling conducted between 11th and 15th June 2017 revealed a total of 15 taxa of airborne cyanobacteria and microalgae. Inhalation of many of the detected taxa, including Synechocystis sp., Synechococcus sp., Bracteacoccus sp., Chlorella sp., Chlorococcum sp., Stichococcus sp., and Amphora sp., poses potential threats to human health. Aside from two green algae, all identified organisms were capable of producing harmful metabolites, including toxins. Moreover, we documented the presence of the cyanobacterium Snowella sp. and the green alga Tetrastrum sp., taxa that had not been previously documented in the atmosphere by other researchers. Our study shows that the Adriatic Sea region seems to be a productive location for future research on airborne cyanobacteria and microalgae in the context of their impacts on human health, especially during the peak of tourism activity.


Assuntos
Microbiologia do Ar , Cianobactérias/isolamento & purificação , Microalgas/isolamento & purificação , Toxinas Bacterianas , Cianobactérias/classificação , Cianobactérias/metabolismo , Humanos , Região do Mediterrâneo , Microalgas/classificação , Microalgas/metabolismo , Saúde Pública , Toxinas Biológicas
2.
Artigo em Inglês | MEDLINE | ID: mdl-32784524

RESUMO

To better understand the characteristics of soil bacterial diversity in different environments, the Laiwu Qilongwan experimental site was selected as it is of great significance for the study of geochemical cycles. The soil CO2, mineral composition and bacterial community were analyzed by an EGM-4 portable environmental gas detector, an X-ray diffractometer and 16S rDNA high-throughput sequencing, and soil bacterial diversity and the relationship between soil bacterial diversity and environmental factors were studied. The results showed that with increasing soil depth, the CO2 content increased, the feldspar and amphibole contents increased, the quartz content decreased, the richness of the soil bacterial community increased, the relative richness of Nitrospirae increased, and Chloroflexi decreased. The dominant bacteria were Proteobacteria, Actinobacteria and Acidobacteria. There were slight differences in soil CO2, mineral composition and dominant bacterial flora at the same depth. Actinobacteria, Proteobacteria and Firmicutes were the dominant phyla of L02. The CO2 was lowest in bare land, and the quartz and K-feldspar contents were the highest. Soil CO2 mainly affected the deep bacterial diversity, while shallow soil bacteria were mainly affected by mineral components (quartz and K-feldspar). At the same depth, amphibole and clay minerals had obvious effects on the bacterial community, while CO2 had obvious effects on subdominant bacteria.


Assuntos
Dióxido de Carbono , Microbiologia do Solo , Solo , Bactérias/genética , Biodiversidade , Cianobactérias/classificação , Cianobactérias/genética , Cianobactérias/isolamento & purificação , Humanos , Minerais , Proteobactérias/classificação , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S/genética
3.
Int J Syst Evol Microbiol ; 70(8): 4714-4724, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32730195

RESUMO

Cyanobacterial strain PS4G was isolated from seepage soil sampled at Pachmarhi, Madhya Pradesh, India, and was characterized using a polyphasic approach. The results of morphological analysis showed that strain PS4G had unique morphological characteristics which were not observed in the other described species of the genus Fortiea. In the 16S rRNA gene phylogenetic analysis inferred using Bayesian inference, maximum-likelihood and neighbour-joining methods, strain PS4G clustered within the clade consisting of the members of the genus Fortiea. Furthermore, in the secondary structure analysis using the D1-D1' helix and BoxB regions of 16S-23S ITS, strain PS4G showed marked differences in comparison with other members of the genus Fortiea. Overall, the morphological, phylogenetic and folded 16S-23S ITS secondary structure examination indicated that strain PS4G represents a novel species of the genus Fortiea. In accordance with the International Code of Nomenclature of Algae, Fungi and Plants we describe a novel species of Fortiea with the name Fortiea necridiiformans sp. nov.


Assuntos
Cianobactérias/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , Cianobactérias/isolamento & purificação , DNA Bacteriano/genética , Índia , Conformação de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Int J Syst Evol Microbiol ; 70(5): 3413-3426, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32375955

RESUMO

Five cyanobacterial strains with Nostoc-like morphology from different localities of the Mazandaran province of Iran were characterized using a polyphasic approach. Three strains clustered within the Aliinostoc clade whereas one each of the remaining two strains clustered within the genera Desmonostoc and Desikacharya. The phylogenetic positioning of all the strains by the bayesian inference, neighbour joining and maximum parsimony methods inferred using 16S rRNA gene indicated them to represent novel species of the genera Aliinostoc, Desmonostoc and Desikacharya. The 16S-23S ITS secondary structure analysis revealed that all five strains under study represented novel species unknown to science. In accordance with the International Code of Nomenclature for algae, fungi and plants we describe three novel species of the genus Aliinostoc and one species each of the genera Desmonostoc and Desikacharya.


Assuntos
Cianobactérias/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , Teorema de Bayes , Cianobactérias/isolamento & purificação , DNA Bacteriano/genética , Irã (Geográfico) , Conformação de Ácido Nucleico , Oryza , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Análise de Sequência de DNA
5.
Environ Microbiol Rep ; 12(3): 258-266, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32227463

RESUMO

The importance of short-chained aliphatic polyamines (PAs) to bacterioplankton-mediated carbon and nitrogen cycles has been repeatedly proposed. However, bacterial taxa and genes involved in the transformations of different PA compounds and their potential spatial variations remain unclear. This study collected surface bacterioplankton from nearshore, offshore, and open ocean stations in the Gulf of Mexico and examined how metatranscriptomes responded to additions of three single PA model compounds (i.e. putrescine, spermidine, or spermine). Our data showed an overrepresentation of genes affiliated with γ-glutamylation and spermidine cleavage pathways in metatranscriptomes received PA amendments and the expression level of each pathway varied among different PA compounds and sampling locations. PA-transforming taxa were affiliated with Actinobacteria, Bacteroidetes, Cyanobacteria, Planctomycetes, and Proteobacteria and their relative importance was also compound and location specific. These findings suggest that PAs are transformed via multiple pathways and by a diversity of marine bacterioplankton in the Gulf of Mexico. The relative importance of different PA transforming pathways and composition of functional microbial communities may be regulated by nutrient status of local environments.


Assuntos
Bactérias , Plâncton , Poliaminas/metabolismo , Água do Mar/microbiologia , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bacteroidetes/classificação , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Cianobactérias/classificação , Cianobactérias/genética , Cianobactérias/isolamento & purificação , Golfo do México , Metagenômica , Microbiota , Nitrogênio/metabolismo , Filogenia , Planctomycetales/classificação , Planctomycetales/genética , Planctomycetales/isolamento & purificação , Plâncton/metabolismo , Plâncton/microbiologia , Proteobactérias/classificação , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S/genética , Água do Mar/química , Transcriptoma
6.
Arch Microbiol ; 202(7): 1717-1728, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32313992

RESUMO

Paeonia ludlowii is indigenous to Tibet and has an important ecological and economic value in China. In Tibet, P. ludlowii has been used in folk medicine with relative success. Plant microbial endophytes play an important role in plant growth, health and ecological function. The diversity of endophytic bacteria associated with P. ludlowii remains poorly understood. In this study, the structure of the endophytic bacterial communities associated with different tissues, including fruits, flowers, leaves, stems, and roots, and rhizosphere soils was analyzed with Illumina MiSeq sequencing of bacterial 16S rDNA. A total of 426,240 sequences and 4847 operational taxonomic units (OTUs) were obtained. The OTUs abundance of roots was higher than that of other tissues; however, the OTUs abundance was similar among different deep soil samples. In the plant tissues, Cyanobacteria was the most abundant bacterial phylum, followed by Proteobacteria; however, the most abundant phyla were Proteobacteria and Acidobacteria in soil samples from three different layers. In addition, the diversity and richness of the microorganisms in the soil were very similar to those in roots but higher than those in other tissues of P. ludlowii. Predictive metagenome analysis revealed that endophytic bacteria play critical functional roles in P. ludlowii. This conclusion could facilitate the study of the ecological functions of endophytic bacteria and their interactions with P. ludlowii to analyze the reasons why this important medicinal plant is becoming endangered.


Assuntos
Biodiversidade , Espécies em Perigo de Extinção , Endófitos/classificação , Endófitos/fisiologia , Paeonia/microbiologia , Rizosfera , Microbiologia do Solo , Cianobactérias/genética , Cianobactérias/isolamento & purificação , DNA Ribossômico/genética , Endófitos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Raízes de Plantas/microbiologia , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S/genética , Tibet
7.
Environ Microbiol Rep ; 12(3): 296-305, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32134187

RESUMO

Bioaerosols are an important component of the total atmospheric aerosol load, with implications for human health, climate feedbacks and the distribution and dispersal of microbial taxa. Bioaerosols are sourced from marine, freshwater and terrestrial surfaces, with different mechanisms potentially responsible for releasing biological particles from these substrates. Little is known about the production of freshwater and terrestrial bioaerosols in polar regions. We used portable collection devices to test for the presence of picocyanobacterial aerosols above freshwater and soil substrates in the southwestern Greenland tundra and the McMurdo Dry Valleys of Antarctica. We show that picocyanobacterial cells are present in the near-surface air at concentrations ranging from 2,431 to 28,355 cells m-3 of air, with no significant differences among substrates or between polar regions. Our concentrations are lower than those measured using the same methods in temperate ecosystems. We suggest that aerosolization is an important process linking terrestrial and aquatic ecosystems in these polar environments, and that future work is needed to explore aerosolization mechanisms and taxon-specific aerosolization rates. Our study is a first step toward understanding the production of bioaerosols in extreme environments dominated by microbial life.


Assuntos
Aerossóis , Cianobactérias/isolamento & purificação , Microbiologia do Ar , Regiões Antárticas , Ecossistema , Água Doce , Groenlândia , Tundra
8.
Sci Rep ; 10(1): 4819, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32179796

RESUMO

Water level fluctuations are an inherent feature regulating the ecological structures and functions of lakes. It is vital to understand the effects of water level fluctuations on bacterial communities and metabolic characteristics in freshwater lakes in a changing world. However, information on the microbial community structure and functional properties in permanently and seasonally flooded areas are lacking. Poyang Lake is a typical seasonal lake linked to the Yangtze River and is significantly affected by water level fluctuations. Bottom water was collected from 12 sampling sites: seven inundated for the whole year (inundated areas) and five drained during the dry season (emerged areas). High-throughput 16S rRNA gene sequencing was used to identify the bacterial communities. The results showed that the taxonomic structure and potential functions of the bacterial communities were significantly different between the inundated and emerged areas. Cyanobacteria was dominant in both areas, but the relative abundance of Cyanobacteria was much higher in the emerged areas than in the inundated areas. Bacterial communities were taxonomically sensitive in the inundated areas and functionally sensitive in the emerged areas. Nitrogen, phosphorus, and dissolved organic carbon concentrations and their ratios, as well as dissolved oxygen, played important roles in promoting the bacterial taxonomic and functional compositional patterns in both areas. According to the metabolic predictions based on 16S rRNA gene sequences, the relative abundance of functional genes related to assimilatory nitrate reduction in the emerged areas was higher than in the inundated areas, and the relative abundance of functional genes related to dissimilatory nitrate reduction in the inundated areas was higher. These differences might have been caused by the nitrogen differences between the permanently and seasonally flooded areas caused by intra-annual water level fluctuations. The relative abundance of functional genes associated with denitrification was not significantly different in the inundated and emerged areas. This study improved our knowledge of bacterial community structure and nitrogen metabolic processes in permanently and seasonally flooded areas caused by water level fluctuations in a seasonal lake.


Assuntos
Inundações , Água Doce/microbiologia , Lagos/microbiologia , Microbiota , Microbiologia da Água , Áreas Alagadas , China , Cianobactérias/genética , Cianobactérias/isolamento & purificação , Cianobactérias/metabolismo , Genes Bacterianos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Microbiota/genética , Microbiota/fisiologia , Nitratos/metabolismo , Nitrogênio/metabolismo , RNA Ribossômico 16S , Estações do Ano
9.
Biomed Res Int ; 2020: 1482109, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32190648

RESUMO

The human gut microbiota is affected by genetic and environmental factors. It remains unclear how host genetic and environmental factors affect the composition and function of gut microbiota in populations living at high altitudes. We used a metagenome-wide analysis to investigate the gut microbiota composition in 15 native Tibetans and 12 Hans living on the Tibetan Plateau. The composition of gut microbiota differed significantly between these two groups (P < 0.05). The Planctomycetes was the most abundant phyla both in native Tibetans and in Hans. Furthermore, the most relatively abundant phyla for native Tibetans were Bacteroidetes (15.66%), Firmicutes (11.10%), Proteobacteria (1.32%), Actinobacteria (1.10%), and Tenericutes (0.35%), while the most relatively abundant phyla for Hans were Bacteroidetes (16.28%), Firmicutes (8.41%), Proteobacteria (2.93%), Actinobacteria (0.49%), and Cyanobacteria (0.21%). The abundance of the majority of genera was significantly higher in Tibetans than in Hans (P < 0.01). The number of microbial genes was 4.9 times higher in Tibetans than in Hans. The metabolic pathways and clusters of orthologous groups differed significantly between the two populations (P < 0.05). The abundance of carbohydrate-active enzyme modules and antibiotic resistance genes was significantly lower in Tibetans compared to Hans (P < 0.05). Our results suggest that different genetic factors (race) and environmental factors (diets and consumption of antibiotics) may play important roles in shaping the composition and function of gut microbiota in populations living at high altitudes.


Assuntos
Altitude , Microbioma Gastrointestinal , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Adulto , Antibacterianos/administração & dosagem , Grupo com Ancestrais do Continente Asiático , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Bacteroidetes/metabolismo , Índice de Massa Corporal , China , Cianobactérias/genética , Cianobactérias/isolamento & purificação , Cianobactérias/metabolismo , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Dieta , Farmacorresistência Bacteriana Múltipla/genética , Fezes/microbiologia , Feminino , Firmicutes/genética , Firmicutes/isolamento & purificação , Firmicutes/metabolismo , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Metagenoma , Proteobactérias/genética , Proteobactérias/isolamento & purificação , Proteobactérias/metabolismo , Análise de Sequência de DNA , Tenericutes/genética , Tenericutes/isolamento & purificação , Tenericutes/metabolismo , Tibet
10.
Int J Nanomedicine ; 15: 49-63, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32021164

RESUMO

Background: The emergence of multi drug-resistant (MDR) bacterial infections and cancer has necessitated the development and discovery of alternative eco-safe antibacterial and anticancer agents. Biogenic fabrication of metallic nanoparticles is an emerging discipline for production of nanoproducts that exert potent anticancer and antibacterial activity, and do not suffer from the limitations inherent in physiochemical synthesis methods. Methodology: In this study, we isolated, purified, and characterized a novel cyanobacteria extract (Desertifilum IPPAS B-1220) to utilize in biofabrication of silver nanoparticles (D-SNPs). D-SNPs were produced by adding Desertifilum extract to silver nitrate solution under controlled conditions. Biofabrication of D-SNPs was confirmed using a UV-Vis spectrophotometer. The resultant D-SNPs were characterized using XRD, FTIR, SEM, and TEM. The toxicity of D-SNPs against five pathogenic bacteria and three cancer cell lines (MCF-7, HepG2, and Caco-2) was evaluated. Results: Formation of D-SNPs was indicated by a color change from pale yellow to dark brown. The peak of the surface plasmon resonance of the D-SNPs was at 421 nm. The XRD detected the crystallinity of D-SNPs. FTIR showed that polysaccharides and proteins may have contributed to the biofabrication of D-SNPs. Under SEM and TEM, the D-SNPs were spherical with diameter ranges from 4.5 to 26 nm. The D-SNPs significantly suppressed the growth of five pathogenic bacteria, and exerted cytotoxic effects against MCF-7, HepG2, and Caco-2 cancer cells with IC50 values of 58, 32, and 90 µg/mL, respectively. Conclusion: These findings showed for the first time the potentiality of novel cyanobacteria strain Desertifilum IPPAS B-1220 to fabricate small SNPs that acted as potent anticancer and antibacterial material against different cancer cell lines and pathogenic bacterial strains. These findings encourage the researchers to focus on cyanobacteria in general and especially Desertifilum sp. IPPAS B-1220 for synthesizing different NPs that opening the window for new applications.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Cianobactérias/química , Nanopartículas Metálicas/química , Prata/química , Antibacterianos/química , Antineoplásicos/química , Células CACO-2 , Cianobactérias/genética , Cianobactérias/isolamento & purificação , Avaliação Pré-Clínica de Medicamentos , Células Hep G2 , Humanos , Células MCF-7 , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Nitrato de Prata/química , Espectroscopia de Infravermelho com Transformada de Fourier , Ressonância de Plasmônio de Superfície
11.
Molecules ; 25(4)2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32075007

RESUMO

ß-Cyclocitral, specifically produced by Microcystis, is one of the volatile organic compounds (VOCs) derived from cyanobacteria and has a lytic activity. It is postulated that ß-cyclocitral is a key compound for regulating the occurrence of cyanobacteria and related microorganisms in an aquatic environment. ß-Cyclocitral is sensitively detected when a high density of the cells is achieved from late summer to autumn. Moreover, it is expected to be involved in changes in the species composition of cyanobacteria in a lake. Although several analysis methods for ß-cyclocitral have already been reported, ß-cyclocitral could be detected using only solid phase micro-extraction (SPME), whereas it could not be found at all using the solvent extraction method in a previous study. In this study, we investigated why ß-cyclocitral was detected using only SPME GC/MS. Particularly, three operations in SPME, i.e., extraction temperature, sample stirring rate, and the effect of salt, were examined for the production of ß-cyclocitral. Among these, heating (60 °C) was critical for the ß-cyclocitral formation. Furthermore, acidification with a 1-h storage was more effective than heating when comparing the obtained amounts. The present results indicated that ß-cyclocitral did not exist as the intact form in cells, because it was formed by heating or acidification of the resulting intermediates during the analysis by SPME. The obtained results would be helpful to understand the formation and role of ß-cyclocitral in an aquatic environment.


Assuntos
Aldeídos/isolamento & purificação , Cianobactérias/isolamento & purificação , Diterpenos/isolamento & purificação , Microcystis/isolamento & purificação , Aldeídos/química , Cianobactérias/química , Cianobactérias/patogenicidade , Diterpenos/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Lagos/microbiologia , Microcystis/química , Microcystis/patogenicidade , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/química
12.
Artigo em Inglês | MEDLINE | ID: mdl-32033450

RESUMO

Urban lakes play an important role in drainage and water storage, regulating urban microclimate conditions, supplying groundwater, and meeting citizens' recreational needs. However, geographical patterns of algal communities associated with urban lakes from a large scale are still unclear. In the present work, the geographical variation of algal communities and water quality parameters in different urban lakes in China were determined. The water quality parameters were examined in the samples collected from north, central, south, and coastal economic zones in China. The results suggested that significant differences in water quality were observed among different geographical distribution of urban lakes. The highest total phosphorus (TP)(0.21 mg/L) and total nitrogen (TN) (3.84 mg/L) concentrations were found in XinHaiHu (XHH) lake, it also showed highest the nitrate nitrogen (NO3--N) (0.39 mg/L),total organic carbon(TOC) (9.77 mg/L), and COD Mn (9.01 mg/L) concentrations among all samples. Environmental and geographic factors also cause large differences in algal cell concentration in different urban lakes, which ranged from 4,700×104 to 247,800 ×104cell/L. Through light microscopy, 6 phyla were identified, which includes Chlorophyta, Bacillariophyta, Cyanophyta, Dinophyta, Euglenophyta, and Cryptophyta. Meanwhile, the heat map with the total 63 algal community composition at the genus level profile different urban lakes community structures are clearly distinguishable. Further analyses showed that the dominant genera were Limnothrixsp., Synedra sp., Cyclotella sp., Nephrocytium sp., Melosirasp., and Scenedesmussp. among all samples. The integrated network analysis indicated that the highly connected taxa (hub) were Fragilariasp.,Scenedesmus sp., and Stephanodiscus sp. The water quality parameters of NO3--N and NH4+-N had significant impacts on the structural composition of the algal community. Additionally, RDA further revealed distinct algal communities in the different urban lakes, and were influenced by NO2--N, Fe, and algal cell concentrations. In summary, these results demonstrate that the pattern of algal communities are highly correlated with geographic location and water quality on a large scale, and these results also give us further understanding of the complex algal communities and effectively managing eutrophication of urban lakes.


Assuntos
Cianobactérias/isolamento & purificação , Monitoramento Ambiental/métodos , Eutrofização , Geografia , Lagos/microbiologia , Microbiologia da Água , Qualidade da Água , China , Cidades/estatística & dados numéricos
13.
Int Microbiol ; 23(3): 453-465, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31933013

RESUMO

Soil salinity is regarded as severe environmental stress that can change the composition of rhizosphere soil bacterial community and import a plethora of harms to crop plants. However, relatively little is known about the relationship between salt stress and root microbial communities in groundnuts. The goal of this study was to assess the effect of salt stress on groundnut growth performance and rhizosphere microbial community structure. Statistical analysis exhibited that salt stress indeed affected groundnut growth and pod yield. Further taxonomic analysis showed that the bacterial community predominantly consisted of phyla Proteobacteria, Actinobacteria, Saccharibacteria, Chloroflexi, Acidobacteria, and Cyanobacteria. Among these bacteria, numbers of Cyanobacteria and Acidobacteria mainly increased, while that of Actinobacteria and Chloroflexi decreased after salt treatment via taxonomic and qPCR analysis. Moreover, Sphingomonas and Microcoleus as the predominant genera in salt-treated rhizosphere soils might enhance salt tolerance as plant growth-promoting rhizobacteria. Metagenomic profiling showed that series of sequences related to signaling transduction, posttranslational modification, and chaperones were enriched in the salt-treated soils, which may have implications for plant survival and salt tolerance. These data will help us better understand the symbiotic relationship between the dominant microbial community and groundnuts and form the foundation for further improvement of salt tolerance of groundnuts via modification of soil microbial community.


Assuntos
Arachis/microbiologia , Microbiota/genética , Rizosfera , Estresse Salino , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Arachis/crescimento & desenvolvimento , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Cianobactérias/genética , Cianobactérias/isolamento & purificação , DNA Bacteriano , Metagenômica , Filogenia , Raízes de Plantas/microbiologia , RNA Ribossômico 16S , Salinidade , Solo/química , Microbiologia do Solo , Sphingomonas/genética , Sphingomonas/isolamento & purificação
14.
Int Microbiol ; 23(3): 467-474, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31933014

RESUMO

Treatment of environmental samples under field conditions may require the application of chemical preservatives, although their use sometimes produces changes in the microbial communities. Sodium azide, a commonly used preservative, is known to differentially affect the growth of bacteria. Application of azide and darkness incubation to Isabel soda lake water samples induced changes in the structure of the bacterial community, as assessed by partial 16S rRNA gene pyrosequencing. Untreated water samples (WU) were dominated by gammaproteobacterial sequences accounting for 86%, while in the azide-treated (WA) samples, this group was reduced to 33% abundance, and cyanobacteria-related sequences became dominant with 53%. Shotgun sequencing and genome recruitment analyses pointed to Halomonas campanensis strain LS21 (genome size 4.07 Mbp) and Synechococcus sp. RS9917 (2.58 Mbp) as the higher recruiting genomes from the sequence reads of WA and WU environmental libraries, respectively, covering nearly the complete genomes. Combined treatment of water samples with sodium azide and darkness has proven effective on the selective enrichment of a cyanobacterial group. This approach may allow the complete (or almost-complete) genome sequencing of Cyanobacteria from metagenomic DNA of different origins, and thus increasing the number of the underrepresented cyanobacterial genomes in the databases.


Assuntos
Cianobactérias/isolamento & purificação , Metagenômica/métodos , Microbiota , Azida Sódica/efeitos adversos , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Cianobactérias/genética , DNA Bacteriano , Microbiologia Ambiental , Inibidores Enzimáticos/efeitos adversos , Genoma Bacteriano , Lagos/microbiologia , Microbiota/genética , Salinidade
15.
Arch Microbiol ; 202(2): 213-223, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31598756

RESUMO

Coxsackievirus B3 (CVB3) and rotavirus (RV) are pathogens of some chronic human diseases. The aim of this study was to determine in vitro antiviral activity of some cyanobacteria against RV and CVB3 infections. Five cyanobacteria were collected from Egypt, identified, and analyzed biochemically. Then, the inhibition of the cytopathic effect of RV and CVB3 viruses by cyanobacterial extracts was examined. Methanol extract of the cyanobacterial isolates showed high antiviral activity against CVB3 with Therapeutic index (TI) of 50.0, 30.0, 27.6, 16.6, and 20.0 for Leptolyngbya boryana, Arthrospira platensis, Nostoc punctiforme, Oscillatoria sp., and Leptolyngbya sp., respectively. The extracts reduced CVB3 titers comparing to 50% tissue culture infectious doses (TCID50) with values 3.25-5.75 log10 of TCID50. Moreover, extracts of A. platensis, and Oscillatoria sp. exhibited high antiviral activity against RV with TI values of 45 and 42.5, respectively, and a reduction in virus titers by 5.75 log10 and 5.5 log10 of TCID50, respectively. Extracts of L. boryana, Leptolyngbya sp., and N. punctiforme had a moderate to low antiviral activity against RV with TI ranging between 2.8 and 7, respectively, and a reduction in virus titers between 0.5 log10 and 1.5 log10 of TCID50, respectively. This study concluded that extracts of five cyanobacterial isolates possess a potent antiviral effect against CVB3 and RV, making them promising sources of new safe antiviral drugs.


Assuntos
Antibiose/fisiologia , Infecções por Coxsackievirus/prevenção & controle , Cianobactérias/metabolismo , Enterovirus Humano B/crescimento & desenvolvimento , Infecções por Rotavirus/prevenção & controle , Rotavirus/crescimento & desenvolvimento , Animais , Antivirais/farmacologia , Linhagem Celular , Chlorocebus aethiops , Cianobactérias/isolamento & purificação , Humanos , Macaca mulatta , Camundongos Endogâmicos BALB C
16.
Animal ; 14(4): 706-715, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31619307

RESUMO

Exploring the composition and structure of the faecal microbial community improves the understanding of the role of the gut microbiota in the gastrointestinal function and the egg-laying performance of hens. Therefore, detection of hen-microbial interactions can explore a new breeding marker for the selection of egg production due to the important role of the gut microbiome in the host's metabolism and health. Recently, the gut microbiota has been recognised as a regulator of host performance, which has led to investigations of the productive effects of changes in the faecal microbiome in various animals. In the present study, a metagenomics analysis was applied to characterise the composition and structural diversity of faecal microbial communities under two selections of egg-laying performance, high (H, n = 30) and low (L, n = 30), using 16S rRNA-based metagenomic association analysis. The most abundant bacterial compositions were estimated based on the operational classification units among samples and between the groups from metagenomic data sets. The results indicated that Firmicutes phylum has higher significant (P < 0.01) in the H group than in the L group. In addition, higher relative abundance phyla of Bacteroides and Fusobacteria were estimated in the H group than the L group, contrasting the phyla of Actinobacteria, Cyanobacteria and Proteobacteria were more relative abundance in the L group. The families (Lactobacillus, Bifidobacterium, Acinetobacter, Flavobacteriaceae, Lachnoclostridum and Rhodococcus) were more abundant in the H group based on the comparison between the H and L groups. Meanwhile, three types of phyla (Proteobacteria, Actinobacteria and Cyanobacteria) and six families (Acinetobacter, Avibacterium, Clostridium, Corynebacterium, Helicobacter and Peptoclostridium) were more abundant in the L group (P < 0.01). Overall, the selection of genotypes has enriched a relationship between the gut microbiota and the egg-laying performance. These findings suggest that the faecal microbiomes of chickens with high egg-laying performance have more diverse activities than those of chickens with low egg-laying performance, which may be related to the metabolism and health of the host and egg production variation.


Assuntos
Bactérias/genética , Galinhas/microbiologia , Microbioma Gastrointestinal/genética , Metagenoma/genética , Metagenômica , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Animais , Bactérias/isolamento & purificação , Galinhas/fisiologia , Cianobactérias/genética , Cianobactérias/isolamento & purificação , Fezes/microbiologia , Feminino , Genótipo , Óvulo , Proteobactérias/genética , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S/genética
17.
Microb Pathog ; 139: 103851, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31715320

RESUMO

BACKGROUND: The presence of the human lung microbiota has been demonstrated in patients with different lung diseases, mainly in sputum samples. However, for study of the alveolar microbiota, a bronchoalveolar lavage (BAL) sample represents the lower respiratory tract (LRT) environment. It is currently unknown whether there is a specific alveolar microbiota profile in human lung diseases, such as pulmonary tuberculosis (TB) and interstitial pneumonia (IP). METHODS: BAL samples from six active TB patients, six IP patients and ten healthy volunteers were used for DNA extraction followed by amplification of the complete bacterial 16S ribosomal RNA gene (16S rDNA). The 16S rDNA was sequenced with a MiSeq Desktop Sequencer, and the data were analysed by QIIME software for taxonomic assignment. RESULTS: The alveolar microbiota in TB and IP patients and healthy volunteers was characterized by six dominant phyla, Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, Fusobacteria and Cyanobacteria. A significant reduction in the abundance of Firmicutes was observed in IP patients. In TB and IP patients, the diversity of the alveolar microbiota was diminished, characterized by a significant reduction in the abundance of the Streptococcus genus and associated with increased Mycobacterium abundance in TB patients and diminished Acinetobacter abundance in IP patients with respect to their abundances in healthy volunteers. However, an important difference was observed between TB and IP patients: the Fusobacterium abundance was significantly reduced in TB patients. Exclusive genera that were less abundant in patients than in healthy volunteers were characterized for each study group. CONCLUSIONS: This study shows that the alveolar microbiota profile in BAL samples from TB and IP patients, representing infectious and non-infectious lung diseases, respectively, is characterized by decreased diversity.


Assuntos
Doenças Pulmonares Intersticiais/microbiologia , Microbiota , Tuberculose Pulmonar/microbiologia , Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Adulto , Idoso , Bacteroidetes/isolamento & purificação , Bacteroidetes/metabolismo , Lavagem Broncoalveolar , Cianobactérias/isolamento & purificação , Cianobactérias/metabolismo , Feminino , Firmicutes/isolamento & purificação , Firmicutes/metabolismo , Fusobactérias/isolamento & purificação , Fusobactérias/metabolismo , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Proteobactérias/isolamento & purificação , Proteobactérias/metabolismo , RNA Bacteriano/genética , RNA Bacteriano/isolamento & purificação , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/isolamento & purificação , Sistema Respiratório/microbiologia , Escarro/microbiologia , Adulto Jovem
18.
Environ Pollut ; 256: 113371, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31672348

RESUMO

Atrazine contamination is of great concern due to its widespread occurrence in shallow lakes. Here, the distribution and degradation of atrazine in acidic and alkaline lake systems were investigated. Meanwhile, the bacterial communities in different sediments and the effects of environmental factors on atrazine-degrading bacteria were evaluated. In the lake systems without plants, atrazine levels in sediment interstitial water reached peak concentrations on the 4th d. More than 90% of atrazine was then degraded in all sediment interstitial water by day 30. Meanwhile, the degradation rate of atrazine in alkaline sediments was faster than that in acidic sediments. Values of hydroxylated metabolites in the acidic lake sediments tended to be greater. Moreover, the amounts of Proteobacteria, Actinobacteria, Firmicute, Nitrospinae, Aminicenantes, Ignavibacteriae and Saccharibacteria in acidic Tangxunhu Lake sediments were significantly different from alkaline Honghu Lake sediments, while the amounts of Cyanobacteria and Saccharibacteria in sediments treated with atrazine were significantly greater than those in sediments without atrazine (P < 0.05). Notably, pH was the most relevant environmental factor in the quantitative variation of atrazine-degrading bacteria, including in Clostridium-sensu-stricto, Pseudomonas, Comamonas and Rhodobacter. The Mantel test results indicated that the degradation of atrazine in different sediments was mainly affected by the sediment physicochemical properties rather than by the addition of atrazine and the cultivation of hydrophytes.


Assuntos
Atrazina/análise , Cianobactérias/isolamento & purificação , Sedimentos Geológicos/química , Lagos/química , Proteobactérias/isolamento & purificação , Poluentes Químicos da Água/análise , China , Sedimentos Geológicos/microbiologia , Concentração de Íons de Hidrogênio , Lagos/microbiologia
19.
Chemosphere ; 240: 124966, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726608

RESUMO

The hepatotoxic cyanotoxins microcystins (MCs) are emerging contaminants naturally produced by cyanobacteria. Yet their ecological role remains unsolved, previous research suggests that MCs have allelopathic effects on competing photosynthetic microorganisms, even eliciting toxic effects on other freshwater cyanobacteria. In this context, the bioluminescent recombinant cyanobacterium Anabaena sp. PCC7120 CPB4337 (hereinafter Anabaena) was exposed to extracts of MCs. These were obtained from eight natural samples from freshwater reservoirs that contained MCs with a concentration range of 0.04-11.9 µg MCs L-1. MCs extracts included the three most common MCs variants (MC-LR, MC-RR, MC-YR) in different proportions (MC-LR: 100-0%; MC-RR: 100-0%; MC-YR: 14.2-0%). The Anabaena bioassay based on bioluminescence inhibition has been successfully used to test the toxicity of many emerging contaminants (e.g., pharmaceuticals) but never for cyanotoxins prior to this study. Exposure of Anabaena to MCs extracts induced a decrease in its bioluminescence with effective concentration decreasing bioluminescence by 50% ranging from 0.4 to 50.5 µg MC L-1 in the different samples. Bioluminescence responses suggested an interaction between MCs variants which was analyzed via the Additive Index method (AI), indicating an antagonistic effect (AI < 0) of MC-LR and MC-RR present in the samples. Additionally, MC extracts exposure triggered an increase of intracellular free Ca2+ in Anabaena. In short, this study supports the use of the Anabaena bioassay as a sensitive tool to assess the presence of MCs at environmentally relevant concentrations and opens interesting avenues regarding the interactions between MCs variants and the possible implication of Ca2+ in the mode of action of MCs towards cyanobacteria.


Assuntos
Bioensaio/métodos , Ecotoxicologia/métodos , Microcistinas/toxicidade , Anabaena/efeitos dos fármacos , Anabaena/metabolismo , Cálcio/metabolismo , Cianobactérias/isolamento & purificação , Cianobactérias/metabolismo , Água Doce/microbiologia
20.
Environ Sci Pollut Res Int ; 26(35): 35860-35870, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31707616

RESUMO

To investigate the relationship between cyanobacteria decomposition and the remobilization of heavy metals in Taihu Lake, the indoor simulation experiments were conducted. The areas of Taihu Lake that undergo harmful algal blooms mostly caused by excessive cyanobacteria have serious problems of heavy metal pollution. The results showed that cyanobacteria decomposition can release heavy metals into the water and change the total contents and chemical speciation of Cr, Ni, Cu, Zn, As, Cd, Hg, and Pb in sediment due to the change of physical and chemical properties in overlying water and sediment. The decomposition rate of cyanobacteria with sediment was clearly faster than that without sediment, and decomposition changed the pH and dissolved oxygen (DO) concentrations in overlying water. The cyanobacteria decomposition reduced the oxidation-reduction potential (ORP), and increased organic matter (OM) and total organic carbon (TOC) in the surface sediment. According to ecological risk assessment, the cyanobacteria decomposition increased the degree of heavy metal pollution and the potential ecological risk in sediment.


Assuntos
Cianobactérias/química , Sedimentos Geológicos/química , Lagos/química , Metais Pesados/análise , Poluentes Químicos da Água/análise , China , Cianobactérias/isolamento & purificação , Ecologia , Poluição Ambiental , Sedimentos Geológicos/análise , Sedimentos Geológicos/microbiologia , Medição de Risco , Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA