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[PMID]:28923725
[Au] Autor:Baoune H; Ould El Hadj-Khelil A; Pucci G; Sineli P; Loucif L; Polti MA
[Ad] Endereço:Laboratoire de protection des écosystème en zones arides et semi-arides, FNSV, Université Kasdi Merbah Ouragla, 30000, Algeria. Electronic address: baounehafida@hotmail.fr.
[Ti] Título:Petroleum degradation by endophytic Streptomyces spp. isolated from plants grown in contaminated soil of southern Algeria.
[So] Source:Ecotoxicol Environ Saf;147:602-609, 2018 Jan.
[Is] ISSN:1090-2414
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Petroleum hydrocarbons are well known by their high toxicity and recalcitrant properties. Their increasing utilization around worldwide led to environmental contamination. Phytoremediation using plant-associated microbe is an interesting approach for petroleum degradation and actinobacteria have a great potential for that. For this purpose, our study aimed to isolate, characterize, and assess the ability of endophytic actinobacteria to degrade crude petroleum, as well as to produce plant growth promoting traits. Seventeen endophytic actinobacteria were isolated from roots of plants grown naturally in sandy contaminated soil. Among them, six isolates were selected on the basis of their tolerance to petroleum on solid minimal medium and characterized by 16S rDNA gene sequencing. All petroleum-tolerant isolates belonged to the Streptomyces genus. Determination by crude oil degradation by gas chromatorgraph-flame ionization detector revealed that five strains could use petroleum as sole carbon and energy source and the petroleum removal achieved up to 98% after 7 days of incubation. These isolates displayed an important role in the degradation of the n-alkanes (C -C ), aromatic and polycyclic aromatic hydrocarbons. All strains showed a wide range of plant growth promoting features such as siderophores, phosphate solubilization, 1-aminocyclopropane-1-carboxylate deaminase, nitrogen fixation and indole-3-acetic acid production as well as biosurfactant production. This is the first study highlighting the petroleum degradation ability and plant growth promoting attributes of endophytic Streptomyces. The finding suggests that the endophytic actinobacteria isolated are promising candidates for improving phytoremediation efficiency of petroleum contaminated soil.
[Mh] Termos MeSH primário: Endófitos/metabolismo
Petróleo/análise
Plantas/microbiologia
Poluentes do Solo/análise
Streptomyces/metabolismo
[Mh] Termos MeSH secundário: Argélia
Biodegradação Ambiental
Carbono-Carbono Liases/metabolismo
Endófitos/crescimento & desenvolvimento
Fixação de Nitrogênio/efeitos dos fármacos
Desenvolvimento Vegetal/efeitos dos fármacos
Plantas/metabolismo
Solo/química
Streptomyces/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Petroleum); 0 (Soil); 0 (Soil Pollutants); EC 3.5.99.7 (1-aminocyclopropane-1-carboxylate deaminase); EC 4.1.- (Carbon-Carbon Lyases)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180223
[Lr] Data última revisão:
180223
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170920
[St] Status:MEDLINE


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[PMID]:29321473
[Au] Autor:Zobel M; Davison J; Edwards ME; Brochmann C; Coissac E; Taberlet P; Willerslev E; Moora M
[Ad] Endereço:Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, 51005, Tartu, Estonia.
[Ti] Título:Ancient environmental DNA reveals shifts in dominant mutualisms during the late Quaternary.
[So] Source:Nat Commun;9(1):139, 2018 01 10.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:DNA-based snapshots of ancient vegetation have shown that the composition of high-latitude plant communities changed considerably during the late Quaternary. However, parallel changes in biotic interactions remain largely uninvestigated. Here we show how mutualisms involving plants and heterotrophic organisms varied during the last 50,000 years. During 50-25 ka BP, a cool period featuring stadial-interstadial fluctuations, arbuscular mycorrhizal and non-N-fixing plants predominated. During 25-15 ka BP, a cold, dry interval, the representation of ectomycorrhizal, non-mycorrhizal and facultatively mycorrhizal plants increased, while that of N-fixing plants decreased further. From 15 ka BP, which marks the transition to and establishment of the Holocene interglaciation, representation of arbuscular mycorrhizal plants decreased further, while that of ectomycorrhizal, non-mycorrhizal, N-fixing and wind-pollinated plants increased. These changes in the mutualist trait structure of vegetation may reflect responses to historical environmental conditions that are without current analogue, or biogeographic processes, such as spatial decoupling of mutualist partners.
[Mh] Termos MeSH primário: Evolução Biológica
DNA Antigo/análise
Micorrizas/genética
Plantas/genética
Simbiose
[Mh] Termos MeSH secundário: Ciclo do Carbono/fisiologia
Dióxido de Carbono/química
Dióxido de Carbono/metabolismo
Clima
Ecossistema
Meio Ambiente
História Antiga
Micorrizas/classificação
Nitrogênio/química
Nitrogênio/metabolismo
Fixação de Nitrogênio/fisiologia
Plantas/classificação
Polinização/fisiologia
Datação Radiométrica
[Pt] Tipo de publicação:HISTORICAL ARTICLE; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (DNA, Ancient); 142M471B3J (Carbon Dioxide); N762921K75 (Nitrogen)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180112
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02421-3


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[PMID]:29297848
[Au] Autor:Siddiqi MZ; Choi GM; Im WT
[Ad] Endereço:1​Department of Biotechnology, Hankyong National University, 327 Chungang-no Anseong-si, Kyonggi-do 17579, Republic of Korea.
[Ti] Título:Ciceribacter azotifigens sp. nov., a nitrogen-fixing bacterium isolated from activated sludge.
[So] Source:Int J Syst Evol Microbiol;68(2):482-486, 2018 Feb.
[Is] ISSN:1466-5034
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A Gram-reaction-negative, catalase- and oxidase-positive, aerobic, transparent, motile and rod-shaped bacterium that was capable of fixing dinitrogen (designated strain A.slu09 ), isolated from activated sludge, was characterized by a polyphasic approach to clarify its taxonomic position. Strain A.slu09 was observed to grow optimally at 30 °C and at pH 7.0 on R2A agar medium. Strain A.slu09 showed ß-glucosidase activity, converting the major ginsenoside Rd to ginsenoside F2. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain A.slu09 belongs to the genus Ciceribacter of the family Rhizobiaceae and was most closely related to Ciceribacter lividus MSSRFBL1 (97.8 % similarity). The DNA G+C content was 67.2 mol%. The DNA-DNA hybridization value between strain A.slu09 and C. lividus KCTC 32403 was 16.9±1.17 %. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, aminophospholipid and two glycolipids, and one unknown phospholipid as a minor lipid. The predominant quinone was ubiquinone-10 (Q-10). The major fatty acids were C19 : 0 cyclo ω8c, C18 : 1 ω7c and/or C18 : 1ω6c (summed feature 8) and C18 : 0, a profile that supported the affiliation of A.slu09 to the genus Ciceribacter. Moreover, the physiological and biochemical characteristics and low level of DNA-DNA relatedness allowed the phenotypic and genotypic differentiation of strain A.slu09 from the recognized species of the genus Ciceribacter. Therefore, strain A.slu09 represents a novel species of the genus Ciceribacter, for which the name Ciceribacter azotifigens sp. nov. is proposed. The type strain is A.slu09 (=KACC 19080 =LMG 29962 ).
[Mh] Termos MeSH primário: Fixação de Nitrogênio
Filogenia
Rhizobiaceae/classificação
Esgotos/microbiologia
[Mh] Termos MeSH secundário: Técnicas de Tipagem Bacteriana
Composição de Bases
DNA Bacteriano/genética
Ácidos Graxos/química
Ginsenosídeos
Hibridização de Ácido Nucleico
Fosfolipídeos/química
RNA Ribossômico 16S/genética
República da Coreia
Rhizobiaceae/genética
Rhizobiaceae/isolamento & purificação
Análise de Sequência de DNA
Ubiquinona/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); 0 (Fatty Acids); 0 (Ginsenosides); 0 (Phospholipids); 0 (RNA, Ribosomal, 16S); 0 (Sewage); 0 (ginsenoside F2); 1339-63-5 (Ubiquinone); I7T5V2W47R (Ubiquinone Q2); WB232T95AV (ginsenoside Rd)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180212
[Lr] Data última revisão:
180212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180104
[St] Status:MEDLINE
[do] DOI:10.1099/ijsem.0.002438


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[PMID]:29185955
[Au] Autor:Choi GM; Im WT
[Ad] Endereço:1​Department of Biotechnology, Hankyong National University, 327 Chungang-no Anseong-si, Kyonggi-do 456-749, Republic of Korea.
[Ti] Título:Paraburkholderia azotifigens sp. nov., a nitrogen-fixing bacterium isolated from paddy soil.
[So] Source:Int J Syst Evol Microbiol;68(1):310-316, 2018 Jan.
[Is] ISSN:1466-5034
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterial strain, designated NF2-5-3 , was isolated from a paddy soil in Anseong city, Republic of Korea. This bacterium was characterized to determine its taxonomic position using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NF2-5-3 had a close relationship with, and was related most closely to, members of the genus Paraburkholderia, namely Paraburkholderia caribensis MWAP64 (98.8 % similarity), P. sabiae Br3407 (98.8 %), P. hospita LMG 20598 (98.5 %), P. terrae NBRC 100964 (98.3 %) and P. phymatum STM815 (98.1 %). Growth of strain NF2-5-3 occurred at 15-37 °C, at pH 6.0-8.0 and at NaCl concentrations of 0-2 % (w/v). The major respiratory quinone was ubiquinone 8 (Q-8) and the major fatty acids were C16 : 0, summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c), C17 : 0 cyclo and C16 : 0 3-OH. The polar lipid profile consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, unidentified aminophospholipids, unidentified aminolipids and unidentified polar lipids. The G+C content of the genomic DNA was 64.2 mol%. DNA-DNA relatedness values between strain NF2-5-3 and its closest phylogenetic neighbours were much lower than 70 %. Strain NF2-5-3 could be differentiated phylogenetically and phenotypically from recognized species of the genus Paraburkholderia. The isolate therefore represents a novel species, for which the name Paraburkholderia azotifigens sp. nov. is proposed, with NF2-5-3 (=KACC 18968 =LMG 29961 ) as the type strain.
[Mh] Termos MeSH primário: Burkholderiaceae/classificação
Filogenia
Microbiologia do Solo
[Mh] Termos MeSH secundário: Técnicas de Tipagem Bacteriana
Composição de Bases
Burkholderiaceae/genética
Burkholderiaceae/isolamento & purificação
DNA Bacteriano/genética
Ácidos Graxos/química
Fixação de Nitrogênio
Hibridização de Ácido Nucleico
Oryza
Fosfolipídeos/química
RNA Ribossômico 16S/genética
República da Coreia
Análise de Sequência de DNA
Ubiquinona/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); 0 (Fatty Acids); 0 (Phospholipids); 0 (RNA, Ribosomal, 16S); 1339-63-5 (Ubiquinone); CQA993F7P8 (ubiquinone 8)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180209
[Lr] Data última revisão:
180209
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171130
[St] Status:MEDLINE
[do] DOI:10.1099/ijsem.0.002505


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[PMID]:29281721
[Au] Autor:Kabbadj A; Makoudi B; Mouradi M; Pauly N; Frendo P; Ghoulam C
[Ad] Endereço:Unit of Plant Biotechnology and Symbiosis Agrophysiology, Faculty of Sciences and Techniques, Guéliz, Marrakesh, Morocco.
[Ti] Título:Physiological and biochemical responses involved in water deficit tolerance of nitrogen-fixing Vicia faba.
[So] Source:PLoS One;12(12):e0190284, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Climate change is increasingly impacting the water deficit over the world. Because of drought and the high pressure of the rising human population, water is becoming a scarce and expensive commodity, especially in developing countries. The identification of crops presenting a higher acclimation to drought stress is thus an important objective in agriculture. The present investigation aimed to assess the adaptation of three Vicia faba genotypes, Aguadulce (AD), Luz d'Otonio (LO) and Reina Mora (RM) to water deficit. Multiple physiological and biochemical parameters were used to analyse the response of the three genotypes to two soil water contents (80% and 40% of field capacity). A significant lower decrease in shoot, root and nodule dry weight was observed for AD compared to LO and RM. The better growth performance of AD was correlated to higher carbon and nitrogen content than in LO and RM under water deficit. Leaf parameters such as relative water content, mass area, efficiency of photosystem II and chlorophyll and carotenoid content were significantly less affected in AD than in LO and RM. Significantly higher accumulation of proline was correlated to the higher performance of AD compared to LO and RM. Additionally, the better growth of AD genotype was related to an important mobilisation of antioxidant enzyme activities such as ascorbate peroxidase and catalase. Taken together, these results allow us to suggest that AD is a water deficit tolerant genotype compared to LO and RM. Our multiple physiological and biochemical analyses show that nitrogen content, leaf proline accumulation, reduced leaf hydrogen peroxide accumulation and leaf antioxidant enzymatic activities (ascorbate peroxidase, guaiacol peroxidase, catalase and polyphenol oxidase) are potential biological markers useful to screen for water deficit resistant Vicia faba genotypes.
[Mh] Termos MeSH primário: Adaptação Fisiológica
Fixação de Nitrogênio
Vicia faba/fisiologia
Água
[Mh] Termos MeSH secundário: Genótipo
Oxirredução
Fotossíntese
Vicia faba/genética
Vicia faba/crescimento & desenvolvimento
Vicia faba/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
059QF0KO0R (Water)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180206
[Lr] Data última revisão:
180206
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171228
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0190284


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[PMID]:27775698
[Au] Autor:König S; Gros O; Heiden SE; Hinzke T; Thürmer A; Poehlein A; Meyer S; Vatin M; Mbéguié-A-Mbéguié D; Tocny J; Ponnudurai R; Daniel R; Becher D; Schweder T; Markert S
[Ad] Endereço:Department of Pharmaceutical Biotechnology, E.M.A. University of Greifswald, Institute of Pharmacy, Greifswald, Germany.
[Ti] Título:Nitrogen fixation in a chemoautotrophic lucinid symbiosis.
[So] Source:Nat Microbiol;2:16193, 2016 Oct 24.
[Is] ISSN:2058-5276
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The shallow water bivalve Codakia orbicularis lives in symbiotic association with a sulfur-oxidizing bacterium in its gills. The endosymbiont fixes CO and thus generates organic carbon compounds, which support the host's growth. To investigate the uncultured symbiont's metabolism and symbiont-host interactions in detail we conducted a proteogenomic analysis of purified bacteria. Unexpectedly, our results reveal a hitherto completely unrecognized feature of the C. orbicularis symbiont's physiology: the symbiont's genome encodes all proteins necessary for biological nitrogen fixation (diazotrophy). Expression of the respective genes under standard ambient conditions was confirmed by proteomics. Nitrogenase activity in the symbiont was also verified by enzyme activity assays. Phylogenetic analysis of the bacterial nitrogenase reductase NifH revealed the symbiont's close relationship to free-living nitrogen-fixing Proteobacteria from the seagrass sediment. The C. orbicularis symbiont, here tentatively named 'Candidatus Thiodiazotropha endolucinida', may thus not only sustain the bivalve's carbon demands. C. orbicularis may also benefit from a steady supply of fixed nitrogen from its symbiont-a scenario that is unprecedented in comparable chemoautotrophic symbioses.
[Mh] Termos MeSH primário: Bivalves/microbiologia
Crescimento Quimioautotrófico
Gammaproteobacteria/fisiologia
Fixação de Nitrogênio
Simbiose
[Mh] Termos MeSH secundário: Animais
Gammaproteobacteria/química
Gammaproteobacteria/genética
Gammaproteobacteria/metabolismo
Brânquias/microbiologia
Redes e Vias Metabólicas/genética
Nitrogenase/metabolismo
Oxirredutases/genética
Filogenia
Proteoma/análise
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Proteome); EC 1.- (Oxidoreductases); EC 1.18.6.1 (Nitrogenase); EC 1.18.6.1 (nitrogenase reductase)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180126
[Lr] Data última revisão:
180126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE
[do] DOI:10.1038/nmicrobiol.2016.193


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[PMID]:27775707
[Au] Autor:Petersen JM; Kemper A; Gruber-Vodicka H; Cardini U; van der Geest M; Kleiner M; Bulgheresi S; Mußmann M; Herbold C; Seah BK; Antony CP; Liu D; Belitz A; Weber M
[Ad] Endereço:Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Research Network Chemistry meets Microbiology, University of Vienna, Althanstrasse 14, Vienna 1090, Austria.
[Ti] Título:Chemosynthetic symbionts of marine invertebrate animals are capable of nitrogen fixation.
[So] Source:Nat Microbiol;2:16195, 2016 Oct 24.
[Is] ISSN:2058-5276
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Chemosynthetic symbioses are partnerships between invertebrate animals and chemosynthetic bacteria. The latter are the primary producers, providing most of the organic carbon needed for the animal host's nutrition. We sequenced genomes of the chemosynthetic symbionts from the lucinid bivalve Loripes lucinalis and the stilbonematid nematode Laxus oneistus. The symbionts of both host species encoded nitrogen fixation genes. This is remarkable as no marine chemosynthetic symbiont was previously known to be capable of nitrogen fixation. We detected nitrogenase expression by the symbionts of lucinid clams at the transcriptomic and proteomic level. Mean stable nitrogen isotope values of Loripes lucinalis were within the range expected for fixed atmospheric nitrogen, further suggesting active nitrogen fixation by the symbionts. The ability to fix nitrogen may be widespread among chemosynthetic symbioses in oligotrophic habitats, where nitrogen availability often limits primary productivity.
[Mh] Termos MeSH primário: Organismos Aquáticos/microbiologia
Bactérias/enzimologia
Bivalves/microbiologia
Cromadoria/microbiologia
Fixação de Nitrogênio
Simbiose
[Mh] Termos MeSH secundário: Animais
Bactérias/genética
Perfilação da Expressão Gênica
Nitrogenase/genética
Proteoma/análise
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Proteome); EC 1.18.6.1 (Nitrogenase)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180126
[Lr] Data última revisão:
180126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE
[do] DOI:10.1038/nmicrobiol.2016.195


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[PMID]:28958725
[Au] Autor:Gomes MP; de Brito JCM; Carvalho Carneiro MML; Ribeiro da Cunha MR; Garcia QS; Figueredo CC
[Ad] Endereço:Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Botânica, Avenida Antônio Carlos, 6627, Pampulha, Caixa Postal 486, 31270-970, Belo Horizonte, Minas Gerais, Brazil; Universidade Federal do Paraná, Setor de Ciências Biológicas, Departamento de Botânica, Avenida
[Ti] Título:Responses of the nitrogen-fixing aquatic fern Azolla to water contaminated with ciprofloxacin: Impacts on biofertilization.
[So] Source:Environ Pollut;232:293-299, 2018 Jan.
[Is] ISSN:1873-6424
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We investigated the ability of the aquatic fern Azolla to take up ciprofloxacin (Cipro), as well as the effects of that antibiotic on the N-fixing process in plants grown in medium deprived (-N) or provided (+N) with nitrogen (N). Azolla was seen to accumulate Cipro at concentrations greater than 160 µg g dry weight when cultivated in 3.05 mg Cipro l , indicating it as a candidate for Cipro recovery from water. Although Cipro was not seen to interfere with the heterocyst/vegetative cell ratios, the antibiotic promoted changes with carbon and nitrogen metabolism in plants. Decreased photosynthesis and nitrogenase activity, and altered plant's amino acid profile, with decreases in cell N concentrations, were observed. The removal of N from the growth medium accentuated the deleterious effects of Cipro, resulting in lower photosynthesis, N-fixation, and assimilation rates, and increased hydrogen peroxide accumulation. Our results shown that Cipro may constrain the use of Azolla as a biofertilizer species due to its interference with nitrogen fixation processes.
[Mh] Termos MeSH primário: Antibacterianos/toxicidade
Ciprofloxacino/toxicidade
Gleiquênias/fisiologia
Poluentes Químicos da Água/toxicidade
[Mh] Termos MeSH secundário: Gleiquênias/crescimento & desenvolvimento
Nitrogênio/metabolismo
Fixação de Nitrogênio
Fotossíntese/efeitos dos fármacos
Testes de Toxicidade
Água/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Water Pollutants, Chemical); 059QF0KO0R (Water); 5E8K9I0O4U (Ciprofloxacin); N762921K75 (Nitrogen)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180122
[Lr] Data última revisão:
180122
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170930
[St] Status:MEDLINE


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[PMID]:28450383
[Au] Autor:Hong H; Shen R; Zhang F; Wen Z; Chang S; Lin W; Kranz SA; Luo YW; Kao SJ; Morel FMM; Shi D
[Ad] Endereço:State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, P.R. China.
[Ti] Título:The complex effects of ocean acidification on the prominent N -fixing cyanobacterium .
[So] Source:Science;356(6337):527-531, 2017 05 05.
[Is] ISSN:1095-9203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Acidification of seawater caused by anthropogenic carbon dioxide (CO ) is anticipated to influence the growth of dinitrogen (N )-fixing phytoplankton, which contribute a large fraction of primary production in the tropical and subtropical ocean. We found that growth and N -fixation of the ubiquitous cyanobacterium decreased under acidified conditions, notwithstanding a beneficial effect of high CO Acidification resulted in low cytosolic pH and reduced N -fixation rates despite elevated nitrogenase concentrations. Low cytosolic pH required increased proton pumping across the thylakoid membrane and elevated adenosine triphosphate production. These requirements were not satisfied under field or experimental iron-limiting conditions, which greatly amplified the negative effect of acidification.
[Mh] Termos MeSH primário: Fixação de Nitrogênio
Nitrogênio/metabolismo
Água do Mar/química
Água do Mar/microbiologia
Trichodesmium/crescimento & desenvolvimento
Trichodesmium/metabolismo
[Mh] Termos MeSH secundário: Dióxido de Carbono/metabolismo
Concentração de Íons de Hidrogênio
Ferro/deficiência
Nitrogenase/metabolismo
Oceanos e Mares
Bombas de Próton/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Proton Pumps); 142M471B3J (Carbon Dioxide); E1UOL152H7 (Iron); EC 1.18.6.1 (Nitrogenase); N762921K75 (Nitrogen)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180117
[Lr] Data última revisão:
180117
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.1126/science.aal2981


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[PMID]:29232381
[Au] Autor:Bogard MJ; Finlay K; Waiser MJ; Tumber VP; Donald DB; Wiik E; Simpson GL; Del Giorgio PA; Leavitt PR
[Ad] Endereço:Department of Biology, University of Regina, Regina, Saskatchewan, Canada.
[Ti] Título:Effects of experimental nitrogen fertilization on planktonic metabolism and CO2 flux in a hypereutrophic hardwater lake.
[So] Source:PLoS One;12(12):e0188652, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Hardwater lakes are common in human-dominated regions of the world and often experience pollution due to agricultural and urban effluent inputs of inorganic and organic nitrogen (N). Although these lakes are landscape hotspots for CO2 exchange and food web carbon (C) cycling, the effect of N enrichment on hardwater lake food web functioning and C cycling patterns remains unclear. Specifically, it is unknown if different eutrophication scenarios (e.g., modest non point vs. extreme point sources) yield consistent effects on auto- and heterotrophic C cycling, or how biotic responses interact with the inorganic C system to shape responses of air-water CO2 exchange. To address this uncertainty, we induced large metabolic gradients in the plankton community of a hypereutrophic hardwater Canadian prairie lake by adding N as urea (the most widely applied agricultural fertilizer) at loading rates of 0, 1, 3, 8 or 18 mg N L-1 week-1 to 3240-L, in-situ mesocosms. Over three separate 21-day experiments, all treatments of N dramatically increased phytoplankton biomass and gross primary production (GPP) two- to six-fold, but the effects of N on autotrophs plateaued at ~3 mg N L-1. Conversely, heterotrophic metabolism increased linearly with N fertilization over the full treatment range. In nearly all cases, N enhanced net planktonic uptake of dissolved inorganic carbon (DIC), and increased the rate of CO2 influx, while planktonic heterotrophy and CO2 production only occurred in the highest N treatments late in each experiment, and even in these cases, enclosures continued to in-gas CO2. Chemical effects on CO2 through calcite precipitation were also observed, but similarly did not change the direction of net CO2 flux. Taken together, these results demonstrate that atmospheric exchange of CO2 in eutrophic hardwater lakes remains sensitive to increasing N loading and eutrophication, and that even modest levels of N pollution are capable of enhancing autotrophy and CO2 in-gassing in P-rich lake ecosystems.
[Mh] Termos MeSH primário: Dióxido de Carbono/metabolismo
Fixação de Nitrogênio
Plâncton/metabolismo
[Mh] Termos MeSH secundário: Biomassa
Monitoramento Ambiental/métodos
Lagos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
142M471B3J (Carbon Dioxide)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180104
[Lr] Data última revisão:
180104
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171213
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0188652



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