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Biologicky aktivní látky produkované řasami a cyanobakteriemi
Maršálek, Blahoslav
Algae and cyanobacteria produce broad spectrum of biologically active compounds - enzymes, vitamins, acids, carbohydrates, exopolysaccharides, odours, tastes or toxins. Effect of these compounds are discussed. Focus is given on cyanotoxins and their effect on the health of aquatic ecosystems and human health as well.
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Mikroprocedura řasového testu
Lukavský, Jaromír
Growth algal bioassay is based on long-term cultivation of a testing alga with tested substance in nutrient solution, or in a sample from nature. The bioassay is at least 3 generations and also chronic affects or influence of repruction process can be so detected. The yield of biomass of testing alga in a sample from nature represent the maximal biomass which could be expected in nature without limitation with light, temperature, CO2 and predation.Miniaturized bioassay is exploating cultivation of algae in wells of an immunological plate in volumes of 0.2 ml. In a plate 9x13 cm, there are 96 wells which enables us to expose 10 samples every in 6 replicates, 2x25 plates in a cultivation unit of size of a common table has capacity of 3 000 miniaturized cultures. Their filling, inoculation and evaluation can be facilitated with a great spectrum of tools and equipments for immunological assays
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Srovnání citlivosti 17 ekotoxikologických bioestů pro detekci cyanotoxinů
Maršálek, Blahoslav ; Bláha, L.
Detection potential of some bioassays used for cyanotoxin detection seems to be promising, but the real comparison of results and the sensitivity to cyanotoxins is imposible, because different authors use different cyanobacterial sample with uncomparable toxin composition, different methods for sample preparation, different design of bioassay, media, etc. A critical comparison of alternative bioassays for cyanotoxins detection, which is important for water management is up to date still missing. The aim of the present study was to compare the sensitivity of 17 bioassays for cyanotoxins detection (with respect to the content of hepatotoxic microcystins )using the same cyanobacterial biomass, and the same sample preparation . Additional aims of this study was as follow: i) can the fractionation of cyanobacterial biomass improve the sensitivity and decrease the variability of bioassays? , ii) which bioassay can more precisely dicrimine the presence of microcystins - is there any dose-response relationships? Cyanobacterial biomass was fractionated by SPE-C18 columns. Crude aqueous extracts, "non-toxic" pigment fraction without microcystins and "toxic" fractions (concentrated microcystins) were compared. This fractionation allowed to determine if the toxicity is due to microcystins, or some other not monitored metabolites present in the complex crude extract.
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Flóra zelených vláknitých řas přírodní památky Kutnar (Podle stavu vegetace v letech 1986-1990)
Gardavský, Alexander ; Skácelová, O. ; Lenský, V.
Filamentous green algae were thoroughly studied from preserved samples collected in the Kutnar pool, from which Cyanophyta had been determined earlier (Skácelová et Komárek, 1989). The progress of eutrophication of the nature reserve (mainly caused by washout from fields) and its terrestrialisation caused changes in communities of both higher plants and filamentous algae. Hydrocharis morsus-ranae and Nymphaea alba have retreated: Cladophora globulina (KÜTZ.) KÜTZ., C. rivularis (L.) HOEK /and C. fracta (O. F. MÜLL. ex VAHL) KÜTZ. and Oedogonium capillare (L.) KÜTZ. at present/ are progressing. The expansion of Oenanthe aquatica is also an important factor in the process.More interesting species are presented and illustrated in detail, particularly: Cylindrocapsa geminella WOLLE, Mougeotia scalaris HASS., Oedogonium rivulare (LeCLERC) A. BRAUN, Schizomeris leibleinii KÜTZ. and Uronema cf. africanum BORGE. Other species include: Chaetophora elegans (ROTH) C. A. AG., Cladophora fracta, C. globulina, C. rivularis, Coleochaete scutata BRÉB. and Oedogonium capillare. Uronema africanum is a new species for Czech and Slovac Republic; Oedogonium rivulare var. tongiense is a new variety for Central Europe (it is the second found of this species in Czech and Slovac Republic).Uronema and Schizomeris were studied thoroughly. Schizomeris leibleinii is morphologically highly variable. Some of their stages resemble the genus Uronema in their morphology but differ cytologically. Starch envelopes of pyrenoids are divided into a few parts in Schizomeris, in contrast to the genus Uronema. The anticipated relationship of the genus Schizomeris to other genera of filamentous green algae requires further study and cultivation.
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Fytoplankton aluviálních tůní
Pithart, David ; Kylbergerová, Magdalena ; Pechar, Libor ; Hrbáček, Jaroslav ; Fiala, Dan ; Bílý, Michal ; Rulík, M.
Phytoplankton of alluvial pools at Lužnice alluvium have been investigated by following methodological approaches: seasonal course of phytoplankton in two pools, extensive sampling (quarterly) of 30 pools, and phytoplankton diurnal vertical migration studies in several pools. Prevailing dominance of phytoflagellates, especially Cryptophyceae and Euglenophyceae and low contribution of coccal forms as Chlorococcales and Cyanophyte has been found as a main feature of phytoplankton community. This is caused by poor mixing of water column (large relative depth, wind protectio), where th ecoccal forms sediment out and are outcompeted by motile forms, able to determinate the position within the water column.
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