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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 59 (1983), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The effect of six long-chained aliphatic amines on 14CO2-reduction, electron transport and the 515 nm absorbance change and shrinkage in isolated intact and broken chloroplasts from spinach (Spinacia oleracea L. cv. Weibulls Medania) was investigated. Five of the six investigated amines affected photosynthesis in intact chloroplasts by inhibiting 14CO2-reduction. In broken chloroplasts the same amines uncoupled electron transport. When added to intact chloroplasts the five amines induced a light-dependent oxygen uptake leading to (he formation of hydrogen peroxide. The oxygen uptake was not due to the amines acting as Mehler reactants. The mode of action, different from that of simple aliphatic amines, was an effect on membrane integrity, first affecting the membrane potential. At higher amine concentrations a more general effect on the ion conditions in the thylakoids was evident.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: A quaternary amine, Aliquat 336, inhibits the growth of the green alga Chlorella emersonii, 14C-fixation of the alga is also inhibited. The effect and the site of action of the compound was studied by using isolated spinach chloroplasts. The carbon dioxide dependent oxygen evolution of the chloroplasts is inhibited directly upon the addition of the amine and the oxygen evolution is replaced by an oxygen uptake. By investigating some electron transport reactions in the chloroplasts we were able to show that Aliquat 336 affects the electron transport on the level of photophosphorylation. The results from the in vivo and the in vitro experiments thus show that the quaternary amine affects the photosynthetic process.Aliquat 336 is a solvent extractant used in several industrial processes for extraction of metals from aqueous solutions. Aliquat 336 could be considered a presumptive water pollutant as the compound could enter a recipient water body and thus affect photosynthesis.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Archives of environmental contamination and toxicology 14 (1985), S. 609-620 
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract The influence on algal growth by six long-chained aliphatic amines, used in industrial solvent extraction processes, was investigated by a conventional algal assay and, in addition, a simple assay where algae were grown in liquid medium in 250 μl cultures on microtitration plates. Loss of solvent extractants from processes to ambient water represent a potential environmental problem. The primary, secondary, tertiary and quaternary amines (with one exception) had EC50-values based on growth rate (ECr) or algal biomass (ECb) at 0.01–0.3 mg/L (20–800 nM). This makes long-chained aliphatic amines about a thousand times more toxic than short-chained amines—on a molar basis. The difference in toxicity was interpreted as being due to different modes of action between the two groups of amines. The diatomAsterionella formosa and the blue-green algaAnabaena flos-aquae were more sensitive to the amines than the green-algaeSelen-astrum capricornutum, Monoraphidium pusillum orChlorella emersonii. The maximum ECmax/ECmin ratio recorded was 19.5, for the primary amine.Anabaena flos-aquae was more sensitive by a factor 2–4 when grown under nitrogen fixation conditions than when supplied with combined nitrogen. Compared to other aquatic organisms, the algae show a particular sensitivity to amines. The microtitration test system was less sensitive than the flask test system. The low sensitivity of the microtitration test system is not an inherent property, but due to the use of an insensitive technique (visual inspection) for detection of algal biomass. The ECr50 and ECb50-values in the flask test system were both heavily time-dependent.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract The effects of combined toxicity were studied, using marine periphyton communities exposed to mixtures of tri-n-butyl tin (TBT) and diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea, DCMU) in indoor aquaria during four weeks. The experimental design of the study followed a central composite design (CCD) and utilized dose-response surface methodology for evaluation of the results. The detection of pollution-induced community tolerance (PICT) was accomplished by short-term (1 h) tests on inhibition of photosynthesis. Both single-toxicant and two-toxicant short-term tests were used. Two tentative measures of tolerance are proposed to achieve convenient comparisons of the tolerances from the two-toxicant tests. With the detection of PICT, effects of the long-term exposure were recorded on diatom species richness, chlorophyll a accumulation and copepod abundance. The decrease of diatom species richness was accompanied by an increased tolerance (PICT), which was detectable by all tolerance measures used. Primary effects on microalgae were recorded as a decrease in chlorophyll a at higher toxicant concentrations. At lower concentrations, primary effects on copepods were found, which resulted in reduced grazing and increased chlorophyll a content.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-3017
    Keywords: short-term toxicity tests ; photosynthesis inhibition ; natural aquatic communities ; attached algae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Short-term toxicity tests using photosynthesis (incorporation of 14C) as a test parameter were performed in order to compare the sensitivities of three marine microalgal communities (phytoplankton, periphyton and epipsammon) to two herbicides, paraquat and simazine. Thirty minutes of pre-exposure to simazine were sufficient to obtain the full effect in all communities, while for paraquat 4 h was required. The bioavailability of paraquat and simazine was not limited by adsorption to sediment in the epipsammon samples. Simazine was more toxic than paraquat for the three communities at similar concentrations. Phytoplankton was slightly more sensitive for both herbicides (EC50 ranges of 9--23 mu m for paraquat and 0.37--0.99 mu m for simazine) than periphyton and epipsammon. These attached communities exhibited different results for each toxicant, periphyton being more sensitive to paraquat (EC50 range 9--21 mu m) and epipsammon to simazine (EC50 range 0.44--1.17 mu m). The three communities presented EC ranges comparable to those found in single species tests, suggesting that different levels of biological organization can exhibit a similar sensibility to toxicants, thus indicating that natural communities are suitable for use in these kinds of toxicity tests
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Hydrobiologia 124 (1985), S. 251-261 
    ISSN: 1573-5117
    Keywords: aliphatic amines ; freshwater ; periphyton ; photosynthesis ; pollution ; textile industry effluent
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The design and performance of a simple, community level ecotoxicological testsystem is reported. Samples of periphyton communities, established on artificial substratum in natural streams were used to study effects on photosynthetic activity in short-term experiments. Photosynthesis was measured as light-dependent oxygen evolution or as 14CO2-incorporation. The variability in photosynthetic activity between samples collected at the same time, expressed as coefficient of variation, was ca 20%. The variation in sensitivity of periphyton photosynthesis as dependent on sampling season was less than threefold for the two long-chained aliphatic amines and the textile industry effluent studied. Effects of the amines on periphyton from five different streams were also investigated. The ratio between maximum and minimum values of sensitivity was 5.6. It is concluded that the variation in sensitivity between different periphyton communities is similar to or less than that observed for fresh-water algal species. Some advantages with regard to ecological realism of using periphyton communities as test systems are discussed.
    Type of Medium: Electronic Resource
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