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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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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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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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Study of Factors Influencing the Development of "Water Bloom" in the Water Reservoir Seč
Forczek, Sándor ; Holík, Josef ; Rederer, L. ; Koza, V.
In this work, we monitored several parameters that influence the development of algal bloom on the\nwater reservoir Sec. Primarily climatic conditions belong to the monitored parameters that influence\nthe population dynamics of algae (air temperature and rainfall, incident light), temperature\nstratification of water, concentration of oxygen, concentrations of total phosphorus, phosphate,\nvarious forms of nitrogen and organic substances, turbidity and also diversity and frequency of\nphytoplankton and zooplankton species. Between 2012 and 2014 have not occurred massive algal\nblooms in the summer months, however the measured physical, chemical and biological data, can be\nused to assess the development of algal population. The population dynamic factors influencing algal\ngrowth must be understand to be able to predict formation and to attempt suppression of algal\nblooms.
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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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Changes in water quality in outdoor swimming pools and swimming areas during the summer season
MARŠÁLKOVÁ, Alena
Good quality of bathing water is an increasingly important factor taken into account when we choose summer vacations, a place to stay for a weekend or a weekend trip destination. In the Czech Republic, bathing waters may be divided according to the legal status into outdoor swimming pools, surface waters used for bathing (swimming areas), other water surfaces or artificial pools. In my thesis I dealt only with outdoor swimming pools and swimming areas. The difference between them lies in the fact that outdoor swimming pools have their own operators who monitor water quality and provide other services in the waterside. Usually there is a fee charged. Swimming areas have no operators and water quality monitoring is placed under the responsibility of regional public health authorities. In the Czech Republic, at present, 188 outdoor swimming pools and swimming areas have been monitored on a regular basis each bathing season. For my research I chose four sites located in the South Bohemian region and four sites in the South Moravian region. For each of these eight sites, I collected results of laboratory analyses, including categories of water quality in bathing seasons of the past five years, it means from the year 2005. With these obtained data I assessed the water quality development both during the bathing season of 2009 and its evolution over the past five years. On the basis of particular categories of water quality I also tried to compare water quality in the South Bohemian and the South Moravian region and also to compare water quality between individual sampling points in one locality. Another aim was to evaluate some measures and interventions made in order to improve water quality. I focused particularly on the pond Olšovec in the South Moravian region and the VN (water reservoir) Orlík in the South Bohemian region. The results do not show any prominent changes in water quality both during the bathing season 2009 and over the past five years. Pronounced fluctuations in water quality were recorded only at certain locations during the 2007 bathing season. Not even between individual regions significant differences in water quality were found. The proportion of individual water quality categories in the two regions did not differ by more than 4%. We can therefore say that water quality in selected localities in the South Bohemian and South Moravian regions is comparable. As for certain measures and interventions implemented to improve water quality, it is important to focus also on the wider neighborhood of the locality, because it could also be a source of substances worsening water quality.
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