Consulta: subjectFacets:"Analytical techniques"
Registros recuperados: 14
Data/hora: 05/06/2024 05:31:07

Microbial extracellular enzyme detection on agar plates by means of fluorogenic methylum-belliferyl-substrates.
Provedor de dados: 5
Autores: Kim, S; Hoppe, H.
A rapid and sensitive method to detect the extracellular enzymatic activity of bacteria colonies grown on agar plates is described. Selective agar media supplemented with protein, starch, chitin, Tween-80, etc. are conventionally used to detect biochemical properties of bacteria. It has been experimentally demonstrated with bacteria pure cultures that fluorogenic Methylumbelliferyl (MUF)-substrates are excellent substrate analogues for normally occurring polymers. Based on MUF-substrate hydrolysis the new method provides reliable qualitative estimates of extracellular enzymatic properties of bacteria within minutes using pure cultures as well as agar plates prepared for colony counts.
Tipo: Text
Palavras-chave: Bacteria; Microbiological culture; Biochemical analysis; Enzymatic activity; Analytical techniques.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-959.pdf

Productivity in tropical upwelling areas considered by a new method of analysis and determination.
Provedor de dados: 5
Autores: Minas, H; Minas, M; Packard, T.
When in frontal zones of upwelling areas, a two-component mixing of nutrient rich upwelled water and oligotrophic offshore waters occurs, the amounts of nutrient consumed (- Delta N) and oxygen produced (+ Delta O2) can be evaluated by a detailed analysis of diagrams, in which salinity is the conservative parameter. By this same method, the corresponding T-S diagram allows a determination of the net heat gain of the upwelling water body during its offshore transport, and consequently the corresponding residence time in the photic zone. By integrating the nutrient consumption over the whole upwelling area, it is possible to obtain a more realistic average value of the productivity than with direct measurements of photosynthetic activity (14C and other...
Tipo: Text
Palavras-chave: Primary production; Dynamical oceanography; T/S diagrams; Fertility; Biomass; Upwelling; Pelagic environment; Analytical techniques; Biological production.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-1527.pdf

Rapid method for determining the sensitivity of sulphate-reducing bacteria to biocides.
Provedor de dados: 5
Autores: Sharma, A; Battersby, N; Stewart, D.
The Minimal Inhibitory Concentration (MIC) of a biocide is usually determined by adding it in various concentrations to a suitable growth medium which is then inoculated with the test bacterium. These cultures are then observed for up to 28 days for growth of the organism as shown by its production of black ferrous sulphide. A method has been developed whereby the MIC of a biocide can be found within 4 days. Instead of noting ferrous sulphide production, this new method measures changes in: 1) optical density and 2) sulphate reduction of a logarithmic culture of the test strain exposed to the biocide.
Tipo: Text
Palavras-chave: Bacteria; Microorganisms; Pesticides; Analytical techniques; Sulfate reduction.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-1016.pdf

Zooplankton nutrition study under conditions close to natural with the use of radioactive phosphorus
Provedor de dados: 5
Autores: Pavlovskaya, T; Zesenko, A.
Lack of a sensitive method for in situ study of the nutrition quantitative characteristics (and food balance in particular) for zooplankton populations in low-productivity regions was the reason for developing one. For the basis of such a method the authors selected the property of radioactive phosphorus isotopes of fast and effective embedding into all plankton components. The method described above allowed not only to quantitatively determine the consumption and transportation of a substance by individual species and populations of zooplankton; it opens new horizons for investigation of the zooplanktonic association role in regeneration of mineral phosphorus.
Tipo: Text
Palavras-chave: Phosphorus cycle; Phosphorus isotopes; Radioactive tracers; Analytical techniques; Food consumption; Zooplankton; Nutrition.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-1524.pdf

Evaluation of the heterotrophic activity in waters by microanalytical methods.
Provedor de dados: 5
Autores: Bertoni, R.
The radiochemical methods proposed for evaluating heterotrophic activity in waters have been severely criticized in recent years because they are not considered to be sufficiently realistic. Thus, the possibility of directly measuring the heterotrophic consumption of naturally occurring Organic Carbon (OC) in fresh water samples incubated under controlled conditions has been evaluated. The analytical performances of two OC analyzers utilizable for this purpose are discussed here, and some examples of the results obtained by the direct measurement of OC consumption are presented. The consumption rates thus measured ranged from 11.6 to 50.2 mu gC/ 1.h. Although the technique discussed here is less sensitive than radiochemical methods, the few assumptions...
Tipo: Text
Palavras-chave: Biogeochemistry; Microbiology; Carbon cycle; Organic carbon; Water; Heterotrophic organisms; Analytical techniques.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-950.pdf

New way to estimate efficient use of energy in copepods during migrations
Provedor de dados: 5
Autores: Petipa, T; Ostrovskaya, N.
It is shown that the energy expenditures on the mechanical movements of copepods depend on the knowledge of character of velocity movements range at active phase. The method of direct estimates of energy expenditures for copepod vertical migration permits to determine more real coefficients of chemical energy utilization on the mechanical work.
Tipo: Text
Palavras-chave: Copepoda; Analytical techniques; Vertical migrations; Locomotion; Energy budget.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-1523.pdf

A laboratory model system for analysing microbial interactions occurring in anoxic estuarine sediments.
Provedor de dados: 5
Autores: Herbert, R; Keith, S.
Defined mixed populations of Clostridium butyricum, Desulfovibrio desulfuricans and Chromatium vinosum co-existed for long periods when grown in a single stage chemostat with glucose as sole carbon source. The nature and availability of the inorganic nitrogen source exerted a major effect on carbon flow in the experimental system. The data show that both the C. butyricum and D. desulfuricans isolates can utilise NO sub(3) as an e super(-)acceptor with an increase in cell yield. Under these growth conditions the free S super(2-) levels were lower resulting in more stable mixed populations. In addition the data show that the C. butyricum produces more oxidised fermentation end-products (acetate) when NO sub(3) super(-) was available and more reduced products...
Tipo: Text
Palavras-chave: Chromatium vinosum; Desulfovibrio desulfuricans; Clostridium butyricum; Biogeochemistry; Models; Bacteria; Detritus; Mineralization; Anoxic sediments; Estuarine sedimentation; Analytical techniques; Carbon cycle; Interspecific relationships; Microbiology.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-947.pdf

Etude comparative des methodes d'analyses de la contamination petroliere dans l'environment marin. 1. Etude fluorometrique.
Provedor de dados: 5
Autores: Awad, Hassan.
Although the determination of hydrocarbons in the marine environment is based usually on the same analytical steps, organic solvents extraction, column chromatography purification, and means for hydrocarbons detection and identification, the variations in the equipment and solvent systems included in the different established techniques hinder to obtain a global idea about the oil contamination state of the seas. Many authors and conferences declared the necessity of carrying out a comparative study on the efficiencies of the various published analytical techniques in this field. According to the facilities available in the laboratory, 25 applications of 16 published techniques were applied on a fixed weight of unique sample of sediments, mussels, fishes,...
Tipo: Text
Palavras-chave: Analytical techniques; Hydrocarbons; Fluorescence spectroscopy.
Ano: 1977
URL: http://archimer.ifremer.fr/doc/1977/publication-1990.pdf

The problems of application of radiocarbon method for estimation of primary production in oligotrophic waters
Provedor de dados: 5
Autores: Krupatkina, D; Berland, B; Maestrini, S.
The errors in primary production estimation by the radiocarbon method may differ from one trophic region to another. Such supposition is based on unequal phytoplanktonic structural characteristics of these regions. These errors are likely to appear rather significant in oligotrophic waters predominated by nano- and ultranano-plankton (the so-called picoplankton). The organic substance of oligotrophic waters is obviously produced by picoplankton for the most part, the need for clarifying possible errors when estimating primary production by the radiocarbon method, which is the purpose of the present work is urgent. For these topics in oligotrophic waters, measurements were carried out in two ways: (1) according to the generally accepted pattern (Sorokin,...
Tipo: Text
Palavras-chave: Methodology; Community composition; Nutrient cycles; Phytoplankton; Ecosystems; Carbon 14; Primary production; Analytical techniques.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-1522.pdf

Le Polymorphisme Electrophoretique : Un Moyen d'Etude des Populations.
Provedor de dados: 5
Autores: Pichot, Paul; Pichot, Yves.
The study of biochemical polymorphisms has been known for some years as an important development. The use of a technique called electrophoresis is at the origin of the progress realized in this science. The electrophoretic detection of genetical heterogeneity existing at the level of some biochemical characters of animal species presents an important theorical and practical interest.
Tipo: Text
Palavras-chave: Pisces; Overfishing; Stock assessment; Population genetics; Electrophoresis; Biochemical analysis; Analytical techniques.
Ano: 1980
URL: http://archimer.ifremer.fr/doc/1980/publication-1909.pdf

Evaluación de la textura de spaghetti seco
Provedor de dados: 20
Autores: de Hombre, R.; Pérez, W.; Córdoba, A.; Pérez, J.
En el presente trabajo se presentan los resultados de la precisión de diferentes técnicas empleando una máquina Instron para medir la textura de spaghetti seco. Se comparó la técnica de flexión o doblado con los métodos que utilizan la celda de Kramer y la cuchilla simple de Warner-Bratzler. Se concluyó que en todos los casos las técnicas presentan buena precisión, pero el método de flexión ofrece los mejores resultados, con la ventaja adicional de que puede calcularse la fuerza de fractura en tensión como propiedad mecánica fundamental que caracteriza el producto.
Tipo: Journal Contribution
Palavras-chave: Texture; In situ measurements; Analytical techniques; Spaghetti.
Ano: 2008
URL: http://hdl.handle.net/1834/5021

Cambios bioquímicos post-mortem en músculos de diferentes especies pesqueras. Determinación de la vida útil de las mismas en frío
Provedor de dados: 20
Autores: Massa, A.E.
Se investigaron los cambios bioquímicos post-mortem y se determinó la vida útil comercial de tres especies pesqueras, muy valoradas por el sector industrial pesquero de nuestro país, durante el almacenamiento en frío: lenguado (Paralichthys patagonicus), corvina rubia (Micropogonias furnieri) y la vieira patagónica (Zygochlamis patagónica). Los cambios bioquímicos relacionados con el ATP y sus productos de degradación, la actividad de las principales enzimas involucradas en el catabolismo del ATP y el pH fueron investigados. En base a los contenidos de los compuestos relacionados con la degradación del ATP se establecieron distintos índices químicos para evaluar la frescura y/o la calidad de estos productos. Por otro lado, se monitorearon los niveles de...
Tipo: Theses and Dissertations
Palavras-chave: Ice; Muscles; Fish spoilage; Analytical techniques; Analytical techniques; Ice; Muscles; Http://aims.fao.org/aos/agrovoc/c_28584; Http://aims.fao.org/aos/agrovoc/c_3782; Http://aims.fao.org/aos/agrovoc/c_5003.
Ano: 2006
URL: http://hdl.handle.net/1834/2602

On the need for independently estimating organic tripton carbon content
Provedor de dados: 27
Autores: Pissierssens, P.; Bergmans, M.; Polk, Ph.
A method is described by which the contribution of Non-Living Particulate Organic Matter (NLPOM) to Total Organic Matter can be determined. The dye Trypan Blue stains only dead organic matter. The surface of the stained particles is used as an indirect measure of the NLPOM-carbon content. Applying this method, it is shown that the bivariate linear regression of POM on chlorophyll &lt;i&gt;a&lt;/i&gt; may produce serious errors in the calculated NLPOM contribution when carbon which is neither tripton- nor chlorophyll-related is present in appreciable quantities.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Analytical techniques; Carbon compounds; Organic matter; Staining.
Ano: 1985
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3283

Determination of methylmercury in biological samples by semiautomated headspace analysis
Provedor de dados: 27
Autores: Decadt, G.; Baeyens, W.F.J.; Bradley, D.; Goeyens, L.
Gas-liquid distribution coefficients of methylmercury halides dissolved in water or benzene have been assessed by using a headspace injection system coupled to a gas chromatograph-microwave-induced plasma system. Vapor concentrations decreased in the following order: CH&lt;sub&gt;3&lt;/sub&gt;HgI &gt; CH&lt;sub&gt;3&lt;/sub&gt;HgBr &gt; CH&lt;sub&gt;3&lt;/sub&gt;HgCl. To transform all methylmercury iodide, iodoacetic acid (IAc) is used as the liberating agent. Methylmercury iodide degradation is prevented by the addition of sodium thiosulfate (0.05 M). The results obtained with internal standard addition are not influenced by other volatile compounds including other mercury compounds. The method has been applied to a series of biological samples. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Analytical techniques; Chemical analysis; Mercury compounds.
Ano: 1985
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3198