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Toxic products of cyanobacteria with the focus on endotoxins
Eršilová, Kateřina ; Načeradská, Jana (advisor) ; Semerád, Jaroslav (referee)
Cyanotoxins are toxic products of cyanobacteria that cause problems (e.g. humans can experience unrecognised health effects), especially when they are overgrown. These cyanotoxins include the group of endotoxins, which includes lipopolysaccharides. Based on a literature search, it was found that the structure of these compounds consists of three chemical parts, Lipid A, a central oligosaccharide and O-Antigen. The structure is not the same for all cyanobacterial species and shows considerable variation. As far as the toxicity of lipopolysaccharides is concerned, it appears to be higher in Gram-negative bacteria than in cyanobacteria. The work in section 4.1 on toxicity states that microcystins do not play a major role in toxicity to Daphnia and that other substances from cyanobacteria will be toxic, while lipopolysaccharides are not excreted. In contrast, Chapter 6 states that lipopolysaccharides from Microcystis are not toxic to Daphnia and that other substances will be behind the toxicity. The thesis further considers that a large number of toxic substances coexist in water blooms, thus synergistic effects are at work in water blooms, hence the toxicity of cultures cultivated in laboratories is lower compared to the toxicity of natural cyanobacterial blooms. Water bloom contain many different...
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Allelopathy of aquatic plants and its possible application to control cyanobacterial blooms
Kolářová, Anna ; Jandová, Kateřina (advisor) ; Kučerová, Andrea (referee)
The excessive growth of phytoplankton and the development of water bloom leading to the damage to aquatic ecosystems are becoming a more and more frequent problem. There are many methods to control the water bloom from which mainly those that use interactions of living organisms have been developing lately, with the utilisation of aquatic plant allelopathy being one of them. Allelopathy is a type of relationship between two organisms when one of them influences the other by secreting allelopathically active compounds in the environment. However, the effect of these secondary metabolites depends on many biotic and abiotic factors, which also has consequences for their potential use to control the water bloom. Although the results of many studies suggest that allelopathy can affect the community of phytoplankton, its role in aquatic ecosystems is still unclear. This thesis summarizes the knowledge about the occurrence of allelopathy among aquatic organisms, the modes of action of allelochemicals and the impacts of the key factors influencing the allelopathic effect. At the same time, it evaluates the prospects of using the allelopathy of aquatic plants to control water bloom and reviews experimental approaches to studying allelopathic interactions.
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Monitoring neurotoxinu \recke{beta}-N-methylamino-L-alaninu v povrchových vodách
PIXA, Jan
This bachelor thesis describes common information about cyanobacteria and cyanotoxins, environmental drivers of cyanobacterial blooms and summaries present knowledges of the occurrence of their secondary metabolite neurotoxin \recke{beta}-N-methylamin-L-alanin. The thesis includes a project proposal regarding monitoring of neurotoxin \recke{beta}-N-methylamin-L-alanin in fishponds and water reservoirs.
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The effect of sampling point on hygienically significant water indicators in natural bathing establishment
Zelinková, Myra ; Benešová, Libuše (advisor) ; Popovský, Jiří (referee)
In this diploma thesis, I deal with the influence of the sampling site on water quality in natural bathing lakes (Hostivar reservoir, Seberak pond and Vyzlovka pond) in this. I have established that hygienically significant kinds of phytoplankton may differ in terms of water quality especially where there are cyanobacteria constituting water bloom. Surface water bloom may be moved by wind to the lee side of the water body (Microcystis sp.). Aphanizomenon flos-aquae water bloom floating in water column can be affected by wind and by water flow (which may be partly affected by wind as well). With the prevailing fibrous Planktothrix agardhii which does not connstitute water bloom the concentration of chlorophyll-a and cyanobacterial cell abundance in individual sampling sites are similar although the concentration of chlorophyll-a a is about 200 g.l-1 . Microcystis sp. and Scenedesmus sp. survive under eutrophic conditions in competition. From the microbiological perspective, water quality can differ within a single sampling site in places at a distance of less than 100 m. Microbial contamination can be caused by bathers, water birds, farm animals and probably by the removing of microorganisms from sand, mud and sediments on the beach or shore. Rain episodes probably increase the abundance of E.coli...
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Eutrofizace povrchových vod
Kunze, David
This bachelor thesis deals with eutrophication of surface waters. People dramatically increase trophic conditions of water ecosystems. Attention is focused on phosphorus as a crucial nutrient for excessive growth of phytoplankton, especially cyanobacteria. Wastewaters are the main source of phosphorus. For this reason, wastewater treatment plants must use the best available techniques to eliminate phosphorus. Phosphorus will be a scarce resource. Author describes the possibilities for recycling of phosphorus. Measures to reduce eutrophication, including completed projects, are also mentioned. Nitrogen sources and the possibility of its removal, are discussed too. Measured concentrations of the basic indicators in representative profiles of river basins show the development of eutrophication in the Czech Republic. Finally, values of these indicators are compared with the limits set by current legislation.
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Detekce a monitoring potenciálně toxických sinicových lipopeptidů
BÁRTOVÁ, Marie
The aim of this study was to design and optimize new PCR primers for detection of potential cyanobacterial producers of cytotoxic lipopeptides puwainaphycins and minutissamides in environmental samples. Samples from two distinct localities were tested, as suggested based on preliminary data. The first set of samples consisted of cyanobacterial soil biofilms from sheep pastures affected by Alveld illness in Norway. The other one contained samples of planktic cyanobacaterial blooms from Protected Landscape Area Třeboň and its vicinity. Three different approaches were used for evaluation of the presence of cyanobacterial lipopeptide producers: microscopy, PCR with the designed primeres, and liquid chromatography-mass spectrometry analysis. Results of this study confirmed the specificity of the newly designed PCR primers. The presence of producers of puwainaphycins/minutissamides was proven at both tested localities.
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The effect of sampling point on hygienically significant water indicators in natural bathing establishment
Zelinková, Myra ; Benešová, Libuše (advisor) ; Popovský, Jiří (referee)
In this diploma thesis, I deal with the influence of the sampling site on water quality in natural bathing lakes (Hostivar reservoir, Seberak pond and Vyzlovka pond) in this. I have established that hygienically significant kinds of phytoplankton may differ in terms of water quality especially where there are cyanobacteria constituting water bloom. Surface water bloom may be moved by wind to the lee side of the water body (Microcystis sp.). Aphanizomenon flos-aquae water bloom floating in water column can be affected by wind and by water flow (which may be partly affected by wind as well). With the prevailing fibrous Planktothrix agardhii which does not connstitute water bloom the concentration of chlorophyll-a and cyanobacterial cell abundance in individual sampling sites are similar although the concentration of chlorophyll-a a is about 200 g.l-1 . Microcystis sp. and Scenedesmus sp. survive under eutrophic conditions in competition. From the microbiological perspective, water quality can differ within a single sampling site in places at a distance of less than 100 m. Microbial contamination can be caused by bathers, water birds, farm animals and probably by the removing of microorganisms from sand, mud and sediments on the beach or shore. Rain episodes probably increase the abundance of E.coli...
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The influence of the surrounding landscape , fishery management , external and internal factors on water quality in ponds
Janáček, Štěpán ; Vach, Marek (advisor)
The thesis deals with the influences that affect water quality in the ponds . It focuses on selected factors which define water quality . These include e.g. the amount of dissolved oxygen in the water , ammonia, etc. To determine the change in water quality in a fish breeding tank, measured quality of water at the inlet of the tank and at its drain. I enter into the analysis and facts about the amount of fish stocking in ponds , basin shape , location of the pond in the countryside , farming in the watershed .
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Methods of reduction of excessive biomass of phytoplankton
CHADTOVÁ, Gabriela
The aim of this study was to prepare review of methods to combat over development of phytoplankton. The work also includes a critical evaluation of usability, efficacy and risks of these methods. The methods to combat over-development of phytoplankton can be divided into direct and indirect. While the direct methods acts directly against phytoplankton, indirect methods are based mostly on reducing the amount of nutrients available for phytoplankton growth. Both of these methods can be further divided to biological, physico-mechanical and chemical. The direct methods of physico-mechanical include ultrasound, flushing and dilution, direct chemical methods include the use of chemical algaecides, coagulants and flocculants. Direct biological methods are especially divided by the principle of parasites(viruses,bacteria and fungi), competitors (algae), allelopathy (extracts from higher plants),predation (protozoa and herbivorous fish). The indirect physico-mechanical methods include extraction and overlapping sediment. Chemical methods are meant by the binding of nutrients to insoluble compound in the sediment and the biological methods are meant use of communities of bacteria for mineralization of sediments. The next part of the work is devoted to the characteristics of algae and cyanobacteria, as well as factors affecting the formation and development of algal blooms. In this part of the work I focus mainly on cyanobacteria, their toxins and the effect they have on the individual components of aquatic ecosystems.
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