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| Registros recuperados: 176 | |
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| Chopin, T; Floc'H, J; Bodeau, B; Penot, M. |
| Phosphorated nutrition of the red alga Chondrus crispus Stackh. is studied is two morphologically very dissimilar forms of the thallus. Phosphorus measurements, which were monthly carried out at different parts of the alga, showed first that the distribution of this element is not homogeneous along the thallus, and second that seasonal variations occur. It is suggested that the classical polymorphism of the species can be taken into account as concerns its physiology. Besides, from absorption and exsorption experiments which were performed with super(32)P as a tracer, it is shown that the high concentration factor of phosphorus in the alga as compared to the environmental seawater (up to 17.9 x 10 super(4)) can be explained as an effect of metabolic process. |
| Tipo: Text |
Palavras-chave: Chondrus crispus; Algae; Distribution; Metabolism; Seasonal variations; Food absorption; Phosphorus; Plant nutrition. |
| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/1983/acte-1175.pdf |
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| Kurata, A. |
| The changes in concentration of thiamine, biotin and vitamin B sub(12) in water of the soaked bottles for 6 h in situ in the north basin of Lake Biwa were examined successively over 30 hours. The concentrations of the vitamins changed comparatively during 6 h. soaking in situ. Generally, the concentrations of thiamine, biotin and vitamin B sub(12) were in high levels in the morning and in low levels in evening both in the soaked bottles and in the surrounding water. The fluctuation ranges in concentration of vitamins in a 5 m deep layer were greater than those in thermocline. From the data obtained with the soaked bottles in situ, it was supposed that the decrease of vitamins in concentration during the daytime surpass consumption of vitamins by... |
| Tipo: Text |
Palavras-chave: Phytoplankton; Microorganisms; Bacteria; Metabolism; Biological production; Vitamin B; Fresh water. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-958.pdf |
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| White, D. |
| Microbes in nature are often concentrated on surfaces where they exist in microcolonies of mixed composition. The assay of these mixed microbial consortia by utilizing biochemical components eliminates the problems associated with cultural selectivity of viable counts or the requirement for quantitative release from surfaces required in some microscopic techniques. The assay of cellular components restricted to subsets of the microbial community gives insights into the community structure of the biofilm whereas assay of cellular components common to all cells can be used for biomass estimations. Formation of endogenous storage materials can be utilized as measures of nutritional status and rates of formation or turnover of specific "signatures" from... |
| Tipo: Text |
Palavras-chave: Bacteria; Fouling; Bioassays; Metabolism; Surfaces; Bacteria collecting devices; Culture media; Microbiological analysis. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-963.pdf |
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| Hermin, M; Daumas, R; Drogue, N. |
| The bacterial activity of the superficial sediment layer was evaluated by incorporation super(14)C-labelled amino-acids mixed an hydrolysate of chlorella cells. Estimation of super(14)C-CO sub(2) super(14)C and super(14)C-A.A. by H.P.L.C. give some informations on the utilization of free dissolved. A.A. and on the transport of labelled compounds from water to sediment. The adsorption mechanism of A.A. on the mineral particles draw to the sediment a larger part of A.A. in the first period; but 28% of this adsorbed A.A. were discharged by an acid treatment. A part of super(14)C-A.A. was incorporated in unhydrolysable organic matter. Di-COOH A.A. are more resistant to bacterial degradation than the other A.A., but arginine is completely metabolized in ten... |
| Tipo: Text |
Palavras-chave: Biogeochemistry; Bacteria; Chromatographic techniques; Metabolism; Amino acids; Sediment water exchanges. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-945.pdf |
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| Robb, F; Muir, D; Davis, C. |
| Some mechanisms of selection which operate on marine Vibrio and Pseudomonas strains during survival in dilute environments have been examined. Mannitol uptake and utilisation systems are more efficient in the Vibrio strain compared with the Pseudomonas strain during starvation survival. A Vibrio mutant strain lacking mannitol uptake showed no greater loss of viability during starvation survival than mannitol positive strains. The Vibrio strain appears to be constitutive with respect to mannitol uptake systems, whereas the Pseudomonas strain examined is inducible. Active uptake systems for glucose, glutamate, alanine and aspartic acid were efficiently maintained during starvation survival in the Vibrio strain. Results suggest that membrane uptake systems... |
| Tipo: Text |
Palavras-chave: Pseudomonas; Vibrio; Bacteria; Physiology; Alcohols; Food conversion; Survival; Starvation; Metabolism. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-960.pdf |
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| Morita, R; Jones, R. |
| The nitrifying bacteria were found to survive 24 weeks in the absence of ammonium without decreasing their number of cell size. Because H sub(2), CO, and CH sub(4) are present in the marine environment, these substrates were investigated as a possible source of the energy of maintenance for the nitrifying bacteria. super(14)CO and super(14)CH sub(4) were found to be oxidized by the nitrifiers. N-serve was found to inhibit the oxidation of CO. Using the nitrifiers' ability to oxide CO, a method for the determination of the nitrification rate was developed. The ability of nitrifiers to oxidize CO may play a significant role in the cycling of CO sub(2) in the marine environment. Whether CO and CH sub(4) oxidation play a role in the survival of nitrifiers in... |
| Tipo: Text |
Palavras-chave: Methane; Carbon dioxide; Survival; Bacteria; Nitrification; Nitrogen cycle; Oxidation; Carbon cycle; Biogeochemistry; Metabolism. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-975.pdf |
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| Portier, R; Meyers, S. |
| The environmental effect and fate of several agricultural and industrial source toxicants were evaluated in controlled laboratory microcosm systems in the presence of the aminopolysaccharide polymer, chitin. Toxicants examined included methyl parathion, phenol, pentachlorophenol, 2,4 dichlorophenol, 1,2 dichloroethane and Kepone. Microcosm operating parameters, including pH/Eh, salinity, temperature, flow rate and sediment/water interface conditions, were based on comparable in situ measurements. Fate analysis predictions were based on mineralization of the parent toxicant compound as measured by chromatographic analysis or super(14)CO sub(2) expiration. Chitin, amended to continuous flow microcosms, promoted either cometabolic or cooxidative... |
| Tipo: Text |
Palavras-chave: Controlled conditions; Chemical pollutants; Industrial wastes; Pesticides; Metabolism; Food webs; Biodegradation; Ecosystems; Microorganisms; Environmental effects; Brackishwater pollution; Estuaries; Toxicants; Chitin. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1011.pdf |
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| Herndl, G; Velimirov, B. |
| Bacterial density of the coelenteric fluid (CF) of some anthozoan species was determined in situ and under laboratory conditions. In all species examined bacterial density of the CF was higher in the gastral cavity than in ambient ranging from 10 super(5) up to 5 x 10 super(6) cells. ml super(-1). Incubation experiments with the CF indicate that a bacterial population within the coelenteron is efficiently controlled by the CF, favoring bacterial growth if bacterial densities are low in the CF and showing clearance activity at high bacterial densities. Feeding of pre-starved anthozoans caused a rapid response of coelenteric rod-shaped bacteria. Evidence is presented that coelenteric bacteria are digested periodically although they contribute 1% to the... |
| Tipo: Text |
Palavras-chave: Anthozoa; Coelomic fluids; Bacteria; Microorganisms; Interspecific relationships; Metabolism; Nutrition. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-989.pdf |
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| Vicente, N; Riva, A; Butler, A. |
| Breathing exchanges of Pinna nobilis L. are studied in situ and in the laboratory with two methods. First method consist in introducing samples of Pinna under a 40l plexiglass bell equipped with haps. The bell is positionned by diving. The consumption of oxygen is observed with water samples and the oxygen concentration is measured with an electronic oxymeter. Experiments which are carried out during nycthemeral cycles are reproduced in the laboratory with the same type of bell. A second method carry into effect an apparatus more sophisticated, who put into circulation a current of water in an airtight thermostated cellule, where a specimen of young Pinna is introduced. This sample is gradually adaptated to the conditions of the medium. Breathing... |
| Tipo: Text |
Palavras-chave: Pinna nobilis; Bivalvia; Temperature; Metabolism; Oxygen consumption; Experimental research; Breathing mixtures; Marine molluscs. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/acte-1761.pdf |
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| Registros recuperados: 176 | |
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