Consulta: subjectFacets:"Dissolved organic matter"
Registros recuperados: 17
Data/hora: 07/06/2024 01:13:28

When riverine dissolved organic matter (DOM) meets labile DOM in coastal waters: changes in bacterial community activity and composition
Provedor de dados: 5
Autores: Blanchet, Marine; Pringault, Olivier; Panagiotopoulos, Christos; Lefevre, Dominique; Charriere, Bruno; Ghiglione, Jean-francois; Fernandez, Camila; Aparicio, Fran L.; Marrase, Celia; Catala, Philippe; Oriol, Louise; Caparros, Jocelyne; Joux, Fabien.
Heterotrophic bacterial communities in marine environments are exposed to a heterogeneous mixture of dissolved organic compounds with different bioreactivity that may control both their activity and composition. The coastal environment is an example of a mixing area where recalcitrant allochthonous organic matter from rivers can encounter labile organic matter from marine phytoplanktonic blooms. The objective of this study was to explore the effects of mixed qualities of dissolved organic matter (DOM) on bacterial community activity (BCA) and bacterial community composition (BCC) and to test for a priming effect when DOM sources are added in combination. Coastal marine bacterial communities were incubated separately with a mixture of amino acids and with...
Tipo: Text
Palavras-chave: Dissolved organic matter; Biodegradation; Coastal waters; Bacterial community composition; Priming effect.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00625/73737/74701.pdf

Mineral and organic soluble forms of zinc, iron and copper: Distribution in the Seine Estuary.
Provedor de dados: 5
Autores: Gandon, R; Guegueniat, P; Fischer, J; Wartel, M.
One characteristic of the Seine Estuary system is the process of sediment resuspension by the specific hydrodynamics of this environment. It's the main factor of trace metals transport. Autotrophic activities also have an effect on the estuary, by pH variation. The behavior of soluble and organic copper, iron, have been studied in relation to salinity in and out of the estuary. The results are compared with those of other estuaries.
Tipo: Text
Palavras-chave: Hydrodynamics; Physicochemical properties; Water properties; Dissolved organic matter; Biogeochemical cycle; Resuspension; Metals; Suspended particulate matter.
Ano: 1985
URL: http://archimer.ifremer.fr/doc/1985/acte-1300.pdf

Dissolved organic nitrogen production and export by meridional overturning in the eastern subpolar North Atlantic
Provedor de dados: 5
Autores: Fernández-castro, Bieito; Álvarez, Marta; Nieto-cid, Mar; Zunino, Patricia; Mercier, Herle; Álvarez-salgado, Xosé Antón.
Dissolved organic matter (DOM) is produced in the surface and exported towards the deep ocean, adding ∼2 PgC yr−1 to the global carbon export. Due to its central role in the Meridional Overturning Circulation (MOC), the eastern subpolar North Atlantic (eSPNA) contributes largely to this export. Here we quantify the transport and budget of dissolved organic nitrogen (DON) in the eSPNA, in a box delimited by the OVIDE 2002 section and the Greenland‐Iceland‐Scotland sills. The MOC exports &gt;15.9 TgN yr−1 of DON downwards and, contrary to the extended view that these are materials of subtropical origin, up to 33% of the vertical flux derives from a net local DON production of 7.1 ± 2.6 TgN yr−1. The low C:N molar ratio of DOM production (7.4 ± 4.1) and the...
Tipo: Text
Palavras-chave: Dissolved organic matter; Nitrogen cycle; Meridional overturning circulation; Subpolar North Atlantic; Metabolic balance.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00485/59622/62649.pdf

Occurrence of phthalate acid esters (PAEs) in the northwestern Mediterranean Sea and the Rhone River
Provedor de dados: 5
Autores: Paluselli, Andrea; Aminot, Yann; Galgani, Francois; Net, Sopheak; Sempere, Richard.
Phthalate acid esters (PAEs) which are mainly anthropogenic molecules with endocrine disrupting effects in animals and humans, have been detected in terrestrial and aquatic environments. However, little is known about their distribution in the Mediterranean Sea, mainly because of analytical difficulties and the high possibility of ambient sample contamination. Here, we report the optimization of an existing protocol for the determination of PAEs in seawater and freshwater samples, as well as the first estimation of the source and distribution of phthalates acid esters (PAEs) in coastal waters from the NW Mediterranean Sea. By passing 1 L of sample through glass cartridges packed with 200 mg of Oasis HLB and eluted with 6 mL of ethyl acetate, the recoveries...
Tipo: Text
Palavras-chave: Phthalates; DEHP; DMP; Dissolved organic matter; Endocrine disruptors.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00389/50012/50601.pdf

Relations between bacterial extracellular enzyme activities and heterotrophic substrate uptake in a brackishwater environment.
Provedor de dados: 5
Autores: Hoppe, H.
Extracellular enzymes mediate the decomposition of polymeric organic compounds in natural waters. In many cases these enzymes comprise a component linked to the bacterial fraction of the aquatic community and react in close association with these cells. An annual survey of microbial activities in a brackish water fjord exhibited an excellent correlation between V sub(m) of proteases (ability to split the substrate analogue methylumbelliferyl-leucine) and V sub(m) as well as T sub(R) for leucine uptake by microorganisms. Hydrolysis rates (H sub(R)) for the decomposition of naturally occurring competitive substrate analogues of the model substrates (methylumbelliferyl-(MUF)-leucine, MUF- alpha -D-glucose, MUF-N-acetyl-glucosamine, MUF-phosphate) drastically...
Tipo: Text
Palavras-chave: Biogeochemistry; Fjords; Bacteria; Brackishwater environment; Seasonal variations; Dissolved organic matter; Interspecific relationships; Hydrolysis; Enzymes.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-952.pdf

Evolution de la complexation des metaux (Ca, Mg, Cd, Pb et Cu) dans l''estuaire de la Seine
Provedor de dados: 5
Autores: Fischer, J; Wartel, M.
Interaction between metallic ions and dissolved organic matter can take major part in the biogeochemical cycle of metals in the aquatic environment. The authors point out copper behavior by the study of complexing capacity of surface and bottom waters. A systematic analysis of major elements in natural waters has allowed for a proposal of geographical distribution of metals.
Tipo: Text
Palavras-chave: River plumes; Dissolved organic matter; Chemical reactions; Salinity; Biogeochemical cycle; Metals; Ion association; Water properties.
Ano: 1985
URL: http://archimer.ifremer.fr/doc/1985/acte-1299.pdf

C18 Sep-Pak extractable dissolved organic copper related to hydrochemistry in the North-West Mediterranean
Provedor de dados: 5
Autores: El Sayed, Mohamed A.; Aminot, Alain.
Extractable organic copper using C18 Sep-Pak cartridges was investigated in seawater after laboratory experiment showed that the (C18 Sep-Pak) cartridges were reliable, in open and coastal waters with normal levels of dissolved organic carbon, for the separation of a specific fraction of organo-copper complexes.Given that the Sep-Pak cartridges retain the hydrophobic fraction of the dissolved organic matter, this extraction technique was applied for studying the characteristics of this particular hydrophobic dissolved organic copper fraction (hDOCu) in the north-western Mediterranean waters. Surface distribution of hDOC is influenced by organic matter input from the river Rhone and its estuary as well as the physical processes affecting the primary...
Tipo: Text
Palavras-chave: Mediterranean sea; Seawater; Dissolved organic matter; Copper compounds.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-1681.pdf

Distribution of phthalates in Marseille Bay (NW Mediterranean Sea)
Provedor de dados: 5
Autores: Paluselli, Andrea; Fauvelle, Vincent; Schmidt, Natascha; Galgani, Francois; Net, Sopheak; Sempere, Richard.
Phthalic Acid Esters (PAEs) are a group of emerging organic contaminants that have become a serious issue because of their ubiquitous presence and hazardous impact on the marine environment worldwide. Seawater samples were collected monthly from December 2013 to November 2014 in the northwestern Mediterranean Sea (Marseille Bay). The samples were analyzed for dissolved organic carbon (DOC) as well as the molecular distribution of dissolved PAEs by using solid phase extraction followed by gas chromatography and mass spectrometry (GC/MS) analyses. The results demonstrated the occurrence of six PAEs, including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BzBP) and...
Tipo: Text
Palavras-chave: Phthalates; DEHP; DMP; Seawater; Dissolved organic matter; Endocrine disruptors.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00413/52482/53358.pdf

Pouvoir complexant des eaux de l'estuaire de la Seine
Provedor de dados: 5
Autores: Fischer, J; Wartel, M; Guegueniat, P; Gandon, R.
Copper has been studied, by the authors, owing to its ability to complex with various organic ligands of natural waters. Metals extraction and liberation can be explained, in part, by this complexing capacity.
Tipo: Text
Palavras-chave: Estuaries; Suspended particulate matter; Dissolved organic matter; Copper; River discharge; Ion association; Metals; Biogeochemical cycle; Water properties.
Ano: 1985
URL: http://archimer.ifremer.fr/doc/1985/acte-1298.pdf

Release of dissolved amino acids by flagellates and ciliates grazing on bacteria
Provedor de dados: 5
Autores: Ferrier-pages, C; Karner, M; Rassoulzadegan, F.
Release of amino acids was examined in the laboratory in the form of dissolved primary amine (DPA) by two marine planktonic protozoa (the oligotrichous ciliate, Strombidium sulcatum and the aplastidic flagellate Pseudobodo sp.) grazing on bacteria. DPA release rates were high (19-25 x 10(-6) and 1.8-2.3 x 10(-6) mu mol DPA cell(-1) h(-1) for flagellates and ciliates, respectively) during the exponential phase, when the ingestion rates were maximum. Release rates were lower during the other growth phases. The release of DPA accounted for 10 % (flagellates) and 16 % (ciliates) of the total nitrogen ingested. Our data suggest that the release of DPA by protozoa could play an important role in supporting bacterial and consequently autotrophic pico- and...
Tipo: Text
Palavras-chave: Acides aminés; Protozoaires; Taux d'excrétion; Matière organique dissoute; Amino acids; Protozoa; Excretion rates; Dissolved organic matter.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00326/43670/43200.pdf

A New Glider-Compatible Optical Sensor for Dissolved Organic Matter Measurements: Test Case from the NW Mediterranean Sea
Provedor de dados: 5
Autores: Cyr, Frédéric; Tedetti, Marc; Besson, Florent; Beguery, Laurent; Doglioli, Andrea M.; Petrenko, Anne A.; Goutx, Madeleine.
The MiniFluo-UV is a new glider-compatible optical sensor for measurements of dissolved organic matter (DOM) in natural waters. The working principle, sensor design and challenges faced during the validation phase are reported. The first in situ application of the sensor during three glider deployments in the NW Mediterranean sea (spring, summer, and fall) are also presented. For these campaigns, the two channels of the sensor were adjusted to target Tryptophan-like (excitation/emission wavelengths λEx/λEm: 275/340 nm) and Phenanthrene-like (λEx/λEm: 255/360 nm) fluorescence. These were chosen because they represent fluorophores of interest commonly found in seawater. While Tryptophan (an amino-acid believed to be a by-product of biological activity) is...
Tipo: Text
Palavras-chave: MiniFluo-UV; Fluorescence; Glider; Dissolved organic matter; Tryptophan; Phenanthrene; Mediterranean Sea.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00654/76597/77747.pdf

Distribution et caractérisation par fluorescence de la matière organique dissoute dans les eaux de la Manche centrale
Provedor de dados: 5
Autores: Ismaili, Mm; Belin, Colette; Lamotte, M; Texier, H.
Intensity and spectral characteristics of the fluorescence of water samples collected along the transect Cherbourg-Isle of Wight during four cruises for excitations at 370, 313 and 270 nm have been investigated within the framework of the FluxManche II program. Seasonal and spatial differences appeared to reflect on the one hand, variations in terrestrial inputs, and on the other hand, waters masses structuring. The observed linear variation of the fluorescence intensity with salinity indicates a gradual dilution of the continental humic material in going from the coasts to the central part of the English Channel. The largest signal was observed for the English coastal waters in agreement with important terrestrial inputs from the Solent river. While the...
Tipo: Text
Palavras-chave: Spectrofluorimétrie; Matière organique dissoute; Manche; Traceur de masse d'eau; Nutriment; Spectrofluorimetry; Dissolved organic matter; English Channel; Tracer of water mass; Nutrient.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00325/43649/43243.pdf

Ultraviolet radiation induces reversal of the bioavailability of DOM to marine bacterioplankton
Provedor de dados: 5
Autores: Obernosterer, I; Sempere, R; Herndl, Gj.
2-fold higher in the &lt;20 kDa fraction than in the bulk DOM. These results clearly indicate that initially bioreactive DOM can be rendered biologically more recalcitrant by exposure to solar radiation, while DOM of initially low bioavailability can be, at least partly, photochemically transformed to compounds of higher biological reactivity.
Tipo: Text
Palavras-chave: Dissolved organic matter; Ultraviolet radiation; DOM-photoreactivity; Bacterioplankton; Southern Ocean.
Ano: 2001
URL: https://archimer.ifremer.fr/doc/00220/33170/31686.pdf

Rôle de l’apport atmosphérique sur les processus de biodégradation et la stoechiométrie de la matière organique dissoute en mer Méditerranée
Provedor de dados: 5
Autores: Djaoudi, Kahina.
Establishing a link between atmospheric deposition and the dissolved organic matter (DOM) pool in the Mediterranean Sea is currently hampered by: (1) a poor knowledge on the surface dissolved phosphate (P) pool, mainly due to low concentrations of dissolved inorganic phosphate (DIP), (2) a critical lack of data on atmospheric fluxes of organic C, N and P and (3) the lack of information on their bioavailability. This PhD thesis aimed at filling these gaps. (1) Relying upon a sensitive determination of DIP, the coverage of the valid dissolved organic phosphate data was enhanced up to 70%, revealing a vertical pattern in the dissolved phosphate biogeochemistry in surface waters. (2) Atmospheric fluxes of soluble organic C, N and P were quantified and were 59...
Tipo: Text
Palavras-chave: Dépôt atmosphérique; Matière organique dissoute; Rapports C:N:P; Nutriments; Mer Méditerranée; Biodisponibilité.; Atmospheric deposition; Dissolved organic matter; C:N:P ratios; Nutrients; Mediterranean Sea; Bioavailability.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00677/78944/81332.pdf

Practical use of anaerobically digested dairy slurry as a soil resource
Provedor de dados: 19
Autores: Tani, Masayuki; Sakamoto, Naoya; Kishimoto, Tadashi; Umetsu, Kazutaka; Nishizaki, Kunio; 谷, 昌幸; 坂本, 直也; 岸本, 正; 梅津, 一孝; 西崎, 邦夫.
2004年8月5日とかちプラザで開催､日本ユネスコ国内委員会主催の帯広農村開発教育国際セミナー(OASERD)国際連合ユネスコアジア太平洋地域教育開発計画事業(APEID)シンポジウム「地球にやさしい農業をめざして : 家畜ふん尿，資源としての有効利用」講演資料
Palavras-chave: Degested daily slurry; Dissolved organic matter; Field application; Industrial waste; Recycled dry chemical extinguishing agents.
Ano: 2004
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/1900

泥炭土における土壌溶液採取方法の検討
Provedor de dados: 19
Autores: 谷, 昌幸; 佐藤, 貴之; 近藤, 錬三; Tani, Masayuki; Sato, Takayuki; Kondo, Renzo.
泥炭からの土壌溶液の採取方法が土壌溶液の組成・特徴に及ぼす影響を4つの方法で比較検討した.対象とした泥炭地は,泥炭の分解度と理化学性が異なる霧多布泥炭地と湧洞沼泥炭地の2地点で,各地点において2×2mの方形区内の4カ所から泥炭および土壌溶液を採取した.減圧ポーラスカップ法(PC法),遠心分離法(CF法),振とう水抽出法(WE法),および泥炭地で一般的に用いられている泥炭を採掘した坑に湧出する水を採取する方法(PW法)の4つの溶液採取方法を用いた.1)各地点4カ所の泥炭の全炭素・窒素含量,繊維含量,腐植化度などの分解度指標および理化学性の変動係数は,おおむね20%以下であった.2)土壌溶液の水質および無機イオン濃度は4つの方法で大きく異なった.PC法,CF法,WE法で採取した土壌溶液は,泥炭の分解程度の違いによって水質が大きく変化することが示された.また,溶存有機物の光学的な特性も採水方法の違いにより異なった.3)PW法により採取した溶液のEC,溶存有機炭素濃度などの水質の変動係数は,両地点とも約20%以下であり,最もばらつきが少なかった.4)PC法,CF法およびWE法により採取した溶液の水質の変動係数は,泥炭の理化学性の変動係数を大きく上回る項目が多かった.また,これら3つの方法により採取した溶液の水質および無機イオン濃度は,泥炭に含まれる植物繊維の影響を強く受けていると考えられた.  The soil solutions in surface peat soils were collected by using four methods : the peatland water method (PW), by which the seepage water in a pit of peatland was...
Palavras-chave: 採取方法; 泥炭; 土壌溶液; 無機イオン組成; 溶存有機物; Dissolved organic matter; Inorganic ion composition; Peat; Sampling methods; Soil solution.
Ano: 2003
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2967

Dissolved Organic Carbon and Nitrogen in Andisol for Six Crop Rotations with Different Soil Management Intensity
Provedor de dados: 117
Autores: Undurraga D,Pablo; Zagal V,Erick; Sepúlveda W,Gloria; Valderrama V,Natalia.
Soil organic matter (OM) content is a quality indicator, but is an inadequate indicator in the short-term because these changes take place slowly, so dissolved organic components have emerged as an alternative. In volcanic soil subjected to different crop rotations with distinct land use intensity, dissolved organic C and N (DOC and DON) were determined as well as their relationship with total C and N contents in the soil, considering the effects of crop rotation, fertilization level, and soil depth. In humid samples of Humic Haploxerands collected at four depths up to 40 cm, DOC and DON contents were determined by extraction with K2SO4 and filtered. Results indicated interaction between the studied factors, DOC fluctuated between 67.8 and 151.7 mg kg-1...
Tipo: Journal article
Palavras-chave: Organic matter; Dissolved organic matter; Total C; Total N; Volcanic soil.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000300018