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Energy utilization of wastes
Havlas, David ; Neděla, René (advisor) ; Jakub, Jakub (referee)
This thesis is conceived as a comprehensive document about energy utilization of waste in appropriate facilities. In the first part, the thesis deals with the issue of waste production and disposal with it. Subsequently, for the introduction to the topic of Waste to Energy, is chronologically described history of energy utilization of waste in Czech Republic and also the technology of facilities, where the combustion with subsequent utilization of energy occurs. Thesis likewise contains a list of currently operating WTE plants and information about future projects for their construction in the Czech Republic. As a crucial part, is considered the assessment of WTE plants, both in terms of the impact on saving fossil fuels, and in terms of potential impact on the environment. The conclusion brings economical evaluation, which is focused on the economic efficiency of investment into these facilities.
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Impact of pesticides on the gut microbiota of human
Kočová, Kateřina ; Rada, Vojtěch (advisor) ; Jakub, Jakub (referee)
Pesticides are substances or mixtures of substances used in agriculture against pests (animals, plants and parasitic fungi), who damage the crops, stocks of agricultural products, food and reduce livestock utility or threaten human health.
The thesis consists of two parts. The first (theoretical) part describes composition and function of gut microbiota; pesticides and their classification, environmental transport and effects of these substances on human health, and glyphosate as the active substance of herbicide Roundup, its mechanism of action, environmental fate and proven effects of glyphosate on human.
The aim of second (practical) part of this thesis was to test impact of pesticide Roundup on the gut microorganisms of human. The impact of pesticide was tested in in vitro pure cultures. Roundup was added in concentrations of glyphosate 17 g/L, 1,7 g/L and
0,17 g/L to the complex media and after cultivation the growth of microorganisms was evaluated. The next samples of stool were collected from human volunteers; these were cultivated similarly in the complex media with different concentrations of glyphosate. The total numbers of microorganisms, bifidobacteria, lactobacilli, enterococci and coliformn bacteria were defined after cultivation.
When the pesticide was tested in pure cultures, concentration of 17 g/L glyphosate significantly inhibited total bacterial growth (P < 0.05), at lower concentrations no difference was observed. The cultivated microorganisms from samples of stool demonstrated only that bifidobacteria are sensitive to glyphosate at the highest used concentration of this pesticide compared with the control sample.
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The application of plant-derived biologically active substances for shelf-life improvement of root vegetable
Krondlová, Marie ; Klouček, Pavel (advisor) ; Jakub, Jakub (referee)
High level of agricultural products processing and especially better storage of products currently represent one of the hottest topics. At the same time, there is a lot of effort to grow crops without chemical substances. Root vegetables, which are consumed a lot, are prone to many harmful and damaging influences. There are several risk factors, including a long vegetation period. This creates an opportunity to use natural substances, in particular essential oils. Their effects are used in various different fields because they are safe for the environment as well as for the human health and the area of food commodities treatment. This study focuses on antibacterial activity testing of several essential oils: satureja, cinnamon, clove, thyme and oregano. Carrot, garden parsley and celery were chosen as representatives of root vegetables. The antibacterial activity was measured by the broth microdilution method. Even though the vegetables were inoculated with pathogenic bacteria, putrefaction did not develop in the specific places. Therefore an isolate from the parsley and the celery was then used to identify several other microorganisms by the MALDI TOF mass spectrometry. Consequently, the minimum inhibitory concentration of essential oils was again tested against these bacteria in in vitro conditions.
There was a demonstrable positive result: the most frequent minimum inhibitory concentration of the cinnamon essential oil was 0.128 mg/ml. At this level the essential oil inhibited eight out of the seventeen tested microorganisms. The other tested essential oils showed some inhibition activity at least against one bacterium in in vitro conditions.
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