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Registros recuperados: 341 | |
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Chamroux, S.; Boucher, G.. |
Chemical and Biological evolution of sediments in closed circuit : I. Nitrogen and bacteria. A series of well controlled sea water closed circuit sand filters allowed the study of chemical and biological regulation processes in the sediment. Bacteria, Nitrogen chemistry and meiofauna were mainly investigated. The evolution of the different forms of nitrogen is rather similar, whatever the organic matter flow in the sediment. As long as the amount of organic input works as limiting factor, bacteria densities are proportional to its flow. No correlation was found between bacteria and chemical parameters in the sand or in the water. The temperature does not seem to play a determinant part neither in the evolution of bacteria nor in the mineralization of... |
Tipo: Text |
Palavras-chave: Circuit clos; Sédiment; Bactéries; Matière organique; Azote; Closed circuit; Sediment; Bacteria; Organic matter; Nitrogen. |
Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00305/41652/40861.pdf |
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Floodgate, G.d.; Lochte, K.; Egan, B.. |
The data obtained in surveys to investigate the bacteriological aspects of the biology of two contrasting frontal systems has shown that the Inherent homeostasis and the complexity of the environment, together with the Imprecision of the data, lead to biomass values that are difficult to interpret in terms of the physical factors governing the formation of fronts. Although biochemical measurements offer some promise of providing more reliable and less confusing information, the oeed to develop high precision methods that can be made very frequently is emphasised. |
Tipo: Text |
Palavras-chave: Bacteria; Discontinuities; Fronts; Methodology. |
Ano: 1982 |
URL: http://archimer.ifremer.fr/doc/00306/41742/40953.pdf |
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Velji, M; Albright, L. |
A technique has been investigated for dispersing adhered marine bacteria from various surfaces prior to direct counting. The bacterial cells were initially preserved and strengthened by use of 3.7% formaldehyde (v/v final concentration). Seawater samples were then treated with 0.001 M of tetrasodium pyrophosphate (final concentration), a sequestering and deflocculating agent. Surface sediment and kelp disc samples were treated with 0.01 M tetrasodium pyrophosphate (final concentration) after having been suspended in 0.44 M sodium chloride solution. These samples were incubated for 15-30 min. Subsequently, the samples were treated with ultrasound (100 W) for 30 to 45 s. This technique resulted in an even dispersion of most bacterial cells in the samples.... |
Tipo: Text |
Palavras-chave: Bacteria; Microbiological analysis; Flocculation; Ultrasonics; Bacterial counters. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-968.pdf |
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Bunetel, L; Segui, A; Guerin, J; Lerman, I; Cormier, M. |
The principle of this method is to evaluate, by counts exercised upon selective media, the relative importance of the different bacteria families in the flora of the coastal waters. It is important to separate the contaminant species and the commensal species in the marine environment. Ten culture media distributed into four categories (selective, non selective, saline and non saline) were examined by numeration. Counts were transferred on a diagram allowing to plot down a profile of bacterial flora of water sampled from a given geographical area. The profiles are arranged by a classification method. The sampling points with similar or adjoining profiles were assembled and marked on the chart. In this way, the authors obtained areas representing the impact... |
Tipo: Text |
Palavras-chave: Bacteria; Coastal waters; Microbiological culture; Sewage disposal; Microbial contamination; Bacterial counters; Bacteria collecting devices. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1004.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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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 |
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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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Dodin, A; Dosso, M; Guillou, M. |
There exists no biochemical test allowing to define the pathogenicity of a bacterium, still less for a Vibrionaceae. Two essential characters are to be retained to hold responsible an isolated germ, for an illness: 1) the binding factor, the identification is difficult but a double diffusion of agar should simplify the method; 2) the search for the choleric toxin or a common part of the choleric toxin (toxin LT or ST of E. coli ). Here again, simplified techniques may be used. The acquirement of a plasmid responsible for the binding factor or for the toxin production of the non-pathogenic Vibrionaceae in the origin of certain epidemic diseases in France and in the world. Frequently, epidemics due to common germs (Aeromonas hydrophila of Africa) lead to... |
Tipo: Text |
Palavras-chave: Aeromonas hydrophila; Vibrionaceae; Bacteria; Ecology; Microorganisms; Hosts; Bacterial diseases; Pathogenic bacteria. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-999.pdf |
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Registros recuperados: 341 | |
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