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Content available remote The in situ influence of Ceratophyllum demersum on a phytoplankton assemblage
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The aim of this work was to present a quantitative and qualitative analysis of a phytoplankton assemblage under the influence of Ceratophyllum demersum L. during a two-year field study. Literature data obtained under laboratory conditions indicate that C. demersum may cause a decrease in the blue-green algae biomass, which is considered to be evidence of the significance of allelopathy. The observations reported in the current paper indicated that there was no clear effect on cyanoprokaryota whereas decreases in the quantity of Cryptophyta, Dinophyta, Chlorophyta, and Chrysophyceae are noted.
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The composition and abundance of cyanobacteria in three lakes of the Polesie Lubelskie (East Poland) were studied in summer periods. Vertical distribution of these algae was analysed in two depths - in epilimnion and deoxygenated metalimnion. Species composition and domination was similar for these two sites. It means that the species like: Limnothrix planctonica (Wołosz.) Meffert, Limnothrix redekei (Van Goor) Meffert, Planktothrixs agardhii (Gom.) Anagn. et Kom., Woronichinianaegeliana (Unger) Elenk. and Microcystis viridis (A. Braun in Rabenhorst) Lemm. are not affected by turbulence of water as well as by oxygen conditions.
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Content available remote Cyanoprokaryota of shallow lakes of Lubuskie Lakeland (mid-western Poland)
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In the summer seasons 2001 - 2004, water samples were collected in 25 shallow lakes in the area of the Lubuskie Lakeland (mid-western Poland). These investigations were the first detailed studies of phytoplankton in this part of Poland. A total of 73 taxa of Cyanoprokaryota were found. Two water blooms of Cyanoprokaryota were documented, with extremely high biomass in one of them. Water blooms were caused by Planktothrix agardhii, Anabaena flos-aquae and Pseudanabaena limnetica. The genus Anabaena represented the highest number of species. The occurrence of an invasive Cyanoprokaryota species - Cylindrospermopsis raciborskii - was detected in two lakes with the highest biomass of cyanoprokaryotic algae (where the above-mentioned blooms were observed).
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Under light stress of 1000 /imol s-1m-2 (λ=400 - 700 nm) for 140 min cyanobacteria mats of "tintenstrich" formations on limestone rocks of Kobylaňska-Valley, west of Cracow, Poland showed reduction of the potential and eiTective quantum yield variables ∆F/Fm' and Fv/Fm3, respectively of PSII and the samples first recovered partly after six days. Also, the Fo level, known to be affected by environmental stress, increased rapidly due to strong light intensity. Sulphite stress (100 mM) was first manifested very clearly after a long, 15h exposure, but not during the first 40 min. Thus, these terrestrial cyanobacteria appear to be less sensitive to sulphite stress than eucaryotic algae, lichens and higher plants studied so far. It is not yet clear if this is due to i) special adaptation of these free living terrestrial cyanobacteria growing in a heavily polluted area, ii) buffering capacity of the limestone support, or iii) other factors.
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This study focused on site-specific preferences of potentially harmful cyanobacterium Gloeotrichia echinulata to occur in lakes with different ecological and trophic conditions. Its pelagic growth was studied in six lakes from June to September in 1986-1988, 2000-2001 and 2009. In total, 78 samples were taken from the epilimnion (stratified lakes) or the whole water column (non-stratified lakes). Analyses of phytoplankton and environmental variables were performed according to standard methods. During summer, a distinct maximum of the Gloeotrichia growth was observed in July or August (the warmest period). Bloom events of G. echinulata occurred in lakes where the light and oxygen conditions were significantly inferior while the phosphorus content remained on a slightly elevated level. The distinct domination of this cyanobacterium (above 40% of the total phytoplankton biomass) was limited to lakes with a high, moderate or even poor ecological status, and to the meso-eutrophic or eutrophic state of lakes. However, G. echinulata occurred in a broader range of ecological and trophic conditions of lakes. The historical approach to mass occurrence of G. echinulata, with its possible contribution to phosphorus translocation from sediment to the pelagic zone, suggested its importance as an indicator of progressive ecological and trophic deterioration of lakes. This indication should be very useful for establishment of main targets in water management.
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The atricle is devoted to the study of the cultivation of cyanobacteria Microcystis aeruginosa (Kützing) Kützing, Microcystis pulverea (H.C.Wood) Forti. in the presence of basalt tuff. The possibility of using basalt tuff as an adsorbing material for regulating the number of cyanobacteria and preventing toxic “water bloom” in fluid circuits. The study analyzes the change in the biomass amount and the dynamics of the proportion of dead cyanobacteria in response to the presence of basalt tuff in the culture medium. It is noted that the use of basalt tuff leads to a decrease in the growth activity of cultures of Microcystis aeruginosa, Microcystis pulverea, manifested in an increase in the number of dead cells and slowdown the accumulation of cyanobacterial biomass. These effects are the result of a decrease in the amount of available nitrogen in the nutrient medium.
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Eukaryotes acquired the ability to process photosynthesis by engulfing a cyanobacterium and transforming it into a genuine organelle called the plastid. This event, named primary endosymbiosis, occurred once more than a billion years ago, and allowed the emergence of the Archaeplastida, a monophyletic supergroup comprising the green algae and plants, the red algae and the glaucophytes. Of the other known cases of symbiosis between cyanobacteria and eukaryotes, none has achieved a comparable level of cell integration nor reached the same evolutionary and ecological success than primary endosymbiosis did. Reasons for this unique accomplishment are still unknown and difficult to comprehend. The exploration of plant genomes has revealed a considerable amount of genes closely related to homologs of Chlamydiae bacteria, and probably acquired by horizontal gene transfer. Several studies have proposed that these transferred genes, which are mostly involved in the functioning of the plastid, may have helped the settlement of primary endosymbiosis. Some of these studies propose that Chlamydiae and cyanobacterial symbionts coexisted in the eukaryotic host of the primary endosymbiosis, and that Chlamydiae provided solutions for the metabolic symbiosis between the cyanobacterium and the host, ensuring the success of primary endosymbiosis. In this review, I present a reevaluation of the contribution of Chlamydiae genes to the genome of Archaeplastida and discuss the strengths and weaknesses of this tripartite model for primary endosymbiosis.
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The paper suggests to worldwide problem of standing waters eutrophication. It describes one of the possible solutions of the problem - design and application of the electrolytic equipment. It indicates effects of its application in practice. The second part of the paper deals with possibilities of economic efficiency evaluation of development and application of the equipment.
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Microorganisms colonising sulphurous waters were found at the bottoms of the spring niches and along spring outflows. Five springs from the Carpathians and two from the Carpathian Foredeep were selected for investigations. Sulphurous flora is represented mainly by sulphuric bacteria. They occur as individual threads, spider-webs, festoons, encrustations and covers. Their colours may be white, creamy, violet, pink and purple. Altogether 31 microorganism taxa: bacteria (16), cyanoprokaryota (3) and algae (12) were identified and illustrated. The bacterial occurrences have been correlated with physico-chemical state of the waters.
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