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Referências encontradas : 286 [refinar]
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  1 / 286 MEDLINE  
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PMID:28464532
Autor:Sogin EM; Putnam HM; Nelson CE; Anderson P; Gates RD
Endereço:Hawai'i Institute of Marine Biology, University of Hawai'i at Manoa, Kane'ohe, HI, USA.
Título:Correspondence of coral holobiont metabolome with symbiotic bacteria, archaea and Symbiodinium communities.
Fonte:Environ Microbiol Rep; 9(3):310-315, 2017 Jun.
ISSN:1758-2229
País de publicação:United States
Idioma:eng
Resumo:Microbial symbiotic partners, such as those associated with Scleractinian corals, mediate biochemical transformations that influence host performance and survival. While evidence suggests microbial community composition partly accounts for differences in coral physiology, how these symbionts affect metabolic pathways remains underexplored. We aimed to assess functional implications of variation among coral-associated microbial partners in hospite. To this end, we characterized and compared metabolomic profiles and microbial community composition from nine reef-building coral species. These data demonstrate metabolite profiles and microbial communities are species-specific and are correlated to one another. Using Porites spp. as a case study, we present evidence that the relative abundance of different sub-clades of Symbiodinium and bacterial/archaeal families are linked to positive and negative metabolomic signatures. Our data suggest that while some microbial partners benefit the union, others are more opportunistic with potential detriment to the host. Consequently, coral partner choice likely influences cellular metabolic activities and, therefore, holobiont nutrition.
Tipo de publicação: JOURNAL ARTICLE


  2 / 286 MEDLINE  
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PMID:29214972
Autor:Vainio EJ; Chiba S; Ghabrial SA; Maiss E; Roossinck M; Sabanadzovic S; Suzuki N; Xie J; Nibert M; Ictv Report Consortium
Endereço:1​Natural Resources Institute Finland (Luke), Helsinki 00790, Finland.
Título:ICTV Virus Taxonomy Profile: Partitiviridae.
Fonte:J Gen Virol; 99(1):17-18, 2018 Jan.
ISSN:1465-2099
País de publicação:England
Idioma:eng
Resumo:The Partitiviridae is a family of small, isometric, non-enveloped viruses with bisegmented double-stranded (ds) RNA genomes of 3-4.8 kbp. The two genome segments are individually encapsidated. The family has five genera, with characteristic hosts for members of each genus: either plants or fungi for genera Alphapartitivirus and Betapartitivirus, fungi for genus Gammapartitivirus, plants for genus Deltapartitivirus and protozoa for genus Cryspovirus. Partitiviruses are transmitted intracellularly via seeds (plants), oocysts (protozoa) or hyphal anastomosis, cell division and sporogenesis (fungi); there are no known natural vectors. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Partitiviridae, which is available at www.ictv.global/report/partitiviridae.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (RNA, Viral)


  3 / 286 MEDLINE  
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PMID:28501690
Autor:Howe PL; Reichelt-Brushett AJ; Clark MW; Seery CR
Endereço:Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia.
Título:Toxicity estimates for diuron and atrazine for the tropical marine cnidarian Exaiptasia pallida and in-hospite Symbiodinium spp. using PAM chlorophyll-a fluorometry.
Fonte:J Photochem Photobiol B; 171:125-132, 2017 Jun.
ISSN:1873-2682
País de publicação:Switzerland
Idioma:eng
Resumo:Effective ecotoxicological risk assessments for herbicides in tropical marine environments are restricted by a lack of toxicity data, sensitive test methods and endpoints for relevant species, and this requires rectification. The symbiotic sea anemone Exaiptasia pallida is a suitable test species, representing the phylum Cnidaria and allowing for assessments of toxicological responses of both the animal host and in-hospite Symbiodinium spp. Pulse amplitude modulated (PAM) chlorophyll-a fluorometry is recognised as a valuable ecotoxicological tool, and here newly-developed test methods are presented using PAM fluorometry to measure herbicide effects on photosynthetic efficiency of in-hospite Symbiodinium spp. Additionally, measurements on healthy laboratory-reared E. pallida provide baseline data demonstrating the normal effective quantum yield (EQY) and the maximum electron transport rate (ETR ) for Symbiodinium spp. in the absence of herbicide stress. Concentration-dependant reductions in the EQY and ETR occurred during diuron and atrazine exposures; a mean 48-h EC50 (effective concentration; 50%) of 8µg/L of diuron was estimated, however atrazine elicited a much lower toxicity. Twelve-day exposures to 10-200µg/L diuron showed that the greatest EQY effect occurred during the first 48h, with little subsequent change. However, longer exposures to the lowest diuron treatment (1µg/L) showed the lowest EQYs after 96h followed by recovery to control levels within 12d. Furthermore, asexual reproduction was inhibited during 12-d exposures to diuron, and 12-d EC50 values of 100 and 132µg/L were estimated to inhibit successful reproduction of pedal lacerates and juveniles by 50% respectively. This study provides much needed data contributions to species sensitivity curves for development of diuron and atrazine water quality guidelines in tropical marine environments.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Herbicides); 1406-65-1 (Chlorophyll); 9I3SDS92WY (Diuron); QJA9M5H4IM (Atrazine); YF5Q9EJC8Y (chlorophyll a)


  4 / 286 MEDLINE  
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PMID:28445483
Autor:Langer JAF; Sharma R; Schmidt SI; Bahrdt S; Horn HG; Algueró-Muñiz M; Nam B; Achterberg EP; Riebesell U; Boersma M; Thines M; Schwenk K
Endereço:Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Biologische Anstalt Helgoland, Germany.
Título:Community barcoding reveals little effect of ocean acidification on the composition of coastal plankton communities: Evidence from a long-term mesocosm study in the Gullmar Fjord, Skagerrak.
Fonte:PLoS One; 12(4):e0175808, 2017.
ISSN:1932-6203
País de publicação:United States
Idioma:eng
Resumo:The acidification of the oceans could potentially alter marine plankton communities with consequences for ecosystem functioning. While several studies have investigated effects of ocean acidification on communities using traditional methods, few have used genetic analyses. Here, we use community barcoding to assess the impact of ocean acidification on the composition of a coastal plankton community in a large scale, in situ, long-term mesocosm experiment. High-throughput sequencing resulted in the identification of a wide range of planktonic taxa (Alveolata, Cryptophyta, Haptophyceae, Fungi, Metazoa, Hydrozoa, Rhizaria, Straminipila, Chlorophyta). Analyses based on predicted operational taxonomical units as well as taxonomical compositions revealed no differences between communities in high CO2 mesocosms (~ 760 µatm) and those exposed to present-day CO2 conditions. Observed shifts in the planktonic community composition were mainly related to seasonal changes in temperature and nutrients. Furthermore, based on our investigations, the elevated CO2 did not affect the intraspecific diversity of the most common mesozooplankter, the calanoid copepod Pseudocalanus acuspes. Nevertheless, accompanying studies found temporary effects attributed to a raise in CO2. Differences in taxa composition between the CO2 treatments could, however, only be observed in a specific period of the experiment. Based on our genetic investigations, no compositional long-term shifts of the plankton communities exposed to elevated CO2 conditions were observed. Thus, we conclude that the compositions of planktonic communities, especially those in coastal areas, remain rather unaffected by increased CO2.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (RNA, Ribosomal, 18S); 1406-65-1 (Chlorophyll); 142M471B3J (Carbon Dioxide); 9007-49-2 (DNA); YF5Q9EJC8Y (chlorophyll a)


  5 / 286 MEDLINE  
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PMID:28407513
Autor:Queiroga FR; Marques-Santos LF; Hégaret H; Sassi R; Farias ND; Santana LN; da Silva PM
Endereço:Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba, Brazil.
Título:Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar-Perkinsus marinus.
Fonte:Aquat Toxicol; 187:100-107, 2017 Jun.
ISSN:1879-1514
País de publicação:Netherlands
Idioma:eng
Resumo:Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4h) and long (48h and 7days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of cyanobacteria; while neither the WCs nor the ECPs modified phagocytosis of the biological particles, zymosan and P. marinus. Our results suggest a negative effect of cyanobacteria from the Synechocystis genus on host immune cells, in contrast to a more beneficial effect on the parasite cell, which could together disrupt the balance of the host-parasite interaction and make oysters more susceptible to P. marinus as well as opportunistic infections.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Marine Toxins); 0 (Water Pollutants, Chemical)


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PMID:28161848
Autor:Chouari R; Leonard M; Bouali M; Guermazi S; Rahli N; Zrafi I; Morin L; Sghir A
Endereço:Faculté des Sciences de Bizerte, UR11ES32 Toxicologie Végétale et Biologie Moléculaire des Micro-organismes, Université de Carthage, Zarzouna, 7021, Bizerte, Tunisia. rakia.chouari@yahoo.fr.
Título:Eukaryotic molecular diversity at different steps of the wastewater treatment plant process reveals more phylogenetic novel lineages.
Fonte:World J Microbiol Biotechnol; 33(3):44, 2017 Mar.
ISSN:1573-0972
País de publicação:Germany
Idioma:eng
Resumo:Wastewater microbiota represents important actors of organic depollution. Nowadays, some species used as bioindicators of the effluent quality are still identified by microscopy. In the present study, we investigated eukaryotic diversity at the different steps of the treatment process of a wastewater treatment plant (aerobic, anaerobic, clarifier basins and anaerobic digester) using the 18S rRNA gene sequencing approach. Of the 1519 analysed sequences, we identified 160 operational taxonomic units. Interestingly, 56.9% of the phylotypes were assigned to novel phylogenetic molecular species since they show <97% sequence identity with their nearest affiliated representative within public databases. Peritrichia ciliates were the most predominant group, with Epistylis as the most common genus. Although anaerobic, the digester appears to harbor many unclassified phylotypes of protozoa species. Novel lineages such as LKM11 and LKM118 were widely represented in the digester. Diversity values given by Shannon indexes show that the clarifier is the most diversified. This work will help designing molecular tools that are fast, reliable, and reproducible for monitoring wastewater depollution and studying phylogenetic relationships among the wonderful world of protists within this anthropogenic ecosystem.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (RNA, Ribosomal, 18S); 0 (Sewage); 0 (Waste Water)


  7 / 286 MEDLINE  
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PMID:28092806
Autor:Reñé A; Alacid E; Figueroa RI; Rodríguez F; Garcés E
Endereço:Institut de Ciències del Mar (CSIC), Pg. Marítim de la Barceloneta, 37-49 08003 Barcelona, Catalonia, Spain. Electronic address: albertrene@icm.csic.es.
Título:Life-cycle, ultrastructure, and phylogeny of Parvilucifera corolla sp. nov. (Alveolata, Perkinsozoa), a parasitoid of dinoflagellates.
Fonte:Eur J Protistol; 58:9-25, 2017 Apr.
ISSN:1618-0429
País de publicação:Germany
Idioma:eng
Resumo:Recent studies of marine protists have revealed parasites to be key components of marine communities. Here we describe a new species of the parasitoid genus Parvilucifera that was observed infecting the dinoflagellate Durinskia baltica in salt marshes of the Catalan coast (NW Mediterranean). In parallel, the same species was detected after the incubation of seawater from the Canary Islands (Lanzarote, NE Atlantic). The successful isolation of strains from both localities allowed description of the life cycle, ultrastructure, and phylogeny of the species. Its infection mechanism consists of a free-living zoospore that penetrates a dinoflagellate cell. The resulting trophont gradually degrades the dinoflagellate cytoplasm while growing in size. Once the host is consumed, schizogony of the parasitoid yields a sporocyte. After cytokinesis is complete, the newly formed zoospores are released into the environment and are ready to infect new host cells. A distinguishing feature of the species is the radial arrangement of its zoospores around the central area of the sporocyte during their formation. The species shows a close morphological similarity with other species of the genus, including P. infectans, P. sinerae, and P. rostrata.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (DNA, Ribosomal)


  8 / 286 MEDLINE  
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PMID:27827804
Autor:Khomich M; Kauserud H; Logares R; Rasconi S; Andersen T
Endereço:Section for Aquatic Biology and Toxicology, Department of Biosciences, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway.
Título:Planktonic protistan communities in lakes along a large-scale environmental gradient.
Fonte:FEMS Microbiol Ecol; 93(4), 2017 Apr 01.
ISSN:1574-6941
País de publicação:England
Idioma:eng
Resumo:Despite their obvious importance, our knowledge about the eukaryotic microbial diversity of inland waters is still limited and poorly documented. We applied 18S rDNA amplicon sequencing to provide a comprehensive analysis of eukaryotic diversity in 74 low-productivity lakes along a 750 km longitudinal transect (5.40-18.52°E) across southern Scandinavia. We detected a wide diversity of pelagic microbial eukaryotes, classified into 1882 operational taxonomic units (OTUs). The highest OTU richness was found in traditional phytoplankton groups like Dinoflagellata, Chrysophyceae, Chlorophyta and Cryptophyta. A total of 53.6% OTUs were primarily autotrophic, while 19.4% of the heterotrophic OTUs belonged to putative parasitic taxa. Except for a longitudinal trend in the relative influence of mixotrophs, there were no significant associations between major functional groups (autotrophs, heterotrophs and parasites) and spatial and environmental variables. Community dissimilarity increased significantly with increasing geographical distance between lakes. In accordance with earlier, microscopy-based surveys in this region, we demonstrate distinct gradients in protistan diversity and community composition, which are better explained by spatial structure than local environment. The strong association between longitude and protistan diversity is probably better explained by differences in regional species pools due to differences in landscape productivity than by dispersal limitation or climatic constraints.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (DNA, Protozoan); 0 (DNA, Ribosomal); 0 (RNA, Ribosomal, 18S)


  9 / 286 MEDLINE  
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PMID:27796418
Autor:Miyaoka Y; Hatamoto M; Yamaguchi T; Syutsubo K
Endereço:Department of Civil and Environmental Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata, 940-2188, Japan.
Título:Eukaryotic Community Shift in Response to Organic Loading Rate of an Aerobic Trickling Filter (Down-Flow Hanging Sponge Reactor) Treating Domestic Sewage.
Fonte:Microb Ecol; 73(4):801-814, 2017 May.
ISSN:1432-184X
País de publicação:United States
Idioma:eng
Resumo:In this study, changes in eukaryotic community structure and water quality were investigated in an aerobic trickling filter (down-flow hanging sponge, DHS) treating domestic sewage under different organic loading rates (OLRs). The OLR clearly influenced both sponge pore water quality and relative flagellates and ciliates (free-swimming, carnivorous, crawling, and stalked protozoa) abundances in the retained sludge. Immediately after the OLR was increased from 1.05 to 1.97 kg chemical oxygen demand (COD) m day , COD and NH -N treatment efficiencies both deteriorated, and relative flagellates and ciliates abundances then increased from 2-8 % to 51-65 % total cells in the middle-bottom part of the DHS reactor. In a continuous operation at a stable OLR (2.01 kg COD m day ), effluent water quality improved, and relative flagellates and ciliates abundances decreased to 15-46 % total cells in the middle-bottom part of the DHS reactor. This result may indicate that flagellates and ciliates preferentially graze on dispersed bacteria, thus, stabilizing effluent water quality. Additionally, to investigate eukaryotic community structure, clone libraries based on the 18S ribosomal ribonucleic acid (rRNA) gene of the retained sludge were constructed. The predominant group was Nucletmycea phylotypes, representing approximately 29-56 % total clones. Furthermore, a large proportion of the clones had <97 % sequence identity in the NCBI database. This result indicates that phylogenetically unknown eukaryotes were present in the DHS reactor. These results provide insights into eukaryotic community shift in the DHS reactor treating domestic sewage.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (RNA, Ribosomal, 18S); 0 (Sewage)


  10 / 286 MEDLINE  
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PMID:27737767
Autor:Belgio E; Santabarbara S; Bína D; Trsková E; Herbstová M; Kana R; Zucchelli G; Prásil O
Endereço:Centre Algatech, Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81 Trebon, Czech Republic.
Título:High photochemical trapping efficiency in Photosystem I from the red clade algae Chromera velia and Phaeodactylum tricornutum.
Fonte:Biochim Biophys Acta; 1858(1):56-63, 2017 01.
ISSN:0006-3002
País de publicação:Netherlands
Idioma:eng
Resumo:In the present work, we report the first comparative spectroscopic investigation between Photosystem I (PSI) complexes isolated from two red clade algae. Excitation energy transfer was measured in PSI from Chromera velia, an alga possessing a split PsaA protein, and from the model diatom Phaeodactylum tricornutum. In both cases, the estimated effective photochemical trapping time was in the 15-25ps range, i.e. twice as fast as higher plants. In contrast to green phototrophs, the trapping time was rather constant across the whole emission spectrum. The weak wavelength dependence was attributed to the limited presence of long-wavelength emitting chlorophylls, as verified by low temperature spectroscopy. As the trapping kinetics of C. velia PSI were barely distinguishable from those of P. tricornutum PSI, it was concluded that the scission of PsaA protein had no significant impact on the overall PSI functionality. In conclusion, the two red clade algae analysed here, carried amongst the most efficient charge separation so far reported for isolated Photosystems.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
Nome de substância:0 (Light-Harvesting Protein Complexes); 0 (Photosystem I Protein Complex); 1406-65-1 (Chlorophyll)



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