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Vliv vybraných leguminóz na mikrobiální aktivity půdy
HODAN, Lukáš
The presented diploma thesis presents an evaluation of the results of the influence of selected legumes on soil microbial activity. The literature review includes a description of legumes in sowing procedures, a description of the spectrum and representatives of the soil microbial community, the main features of soil microbial activity and methods of measuring this activity. The conclusions were preceded by a small-plot experiment on a plot of land managed in an organic farming regime, from which soil basal respiration, as the main parameter of soil microbial activity, was investigated in the laboratory with mixed samples, and further quantification of the total number of microorganisms by the cultivation method.
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Genetic potential for methane metabolism in the Greenland subglacial ecosystem
Rybár, Marek ; Stibal, Marek (advisor) ; Šabacká, Marie (referee)
Subglacial environments, located at the interface of glacier ice and bedrock, represent one of the major ecosystems associated with glaciers and ice sheets. This environment contains liquid water and underlying sediment with large amounts of organic matter overridden during periods of ice advance. Large areas of subglacial sediment are exposed annually by glacier melting and retreat, which affects the subglacial carbon stores and may significantly impact regional carbon fluxes. Due to the widespread anoxia at glacier beds, subglacial environments are potential producers and reservoirs of methane that can be released into the atmosphere as a consequence of glacial retreat. While the presence of methanogens and methane oxidisers has been shown based on 16S rRNA gene data, no data on the functional genetic potential for methane metabolism currently exist. In this study, the first subglacial metagenomes obtained from subglacial sediment exported from beneath the Greenland ice sheet by a meltwater river were used to characterize the metabolic potential for methane metabolism by the identification and quantification of genes involved in methane production and consumption. Functional genes of potential syntrophic pathways were also investigated. Functional genes of methanogenesis/anaerobic oxidation of methane and...
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Comparison of soil microbial activity on sites with different forest management practices
Volánek, Jiří
Presented thesis is focused on microbial activity of forest soils and aims at characterizing some of its parameters on sites with different silvicultural management practices. Coppice, coppice-with-standard and high forest stands were compared in terms of carbon and nitrogen content, content of microbial biomass, enzymatic activity and selected physical properties of soil. Study was conducted between September 2015 and April 2016 on pre-existing TARMAG II research plot near Soběšice, Brno, Czech Republic. Samples were collected during three different calendar seasons, allowing for seasonal dynamicity assessment of the studied parameters. Statistical evaluation detected significant effect of management type on potential respiration of studied soil samples as well as significant effect of seasonality on microbial biomass content in incubated samples, phosphatase activity in fresh soil samples, catalase activity in both fresh and incubated samples and potential respiration of studied samples. Results also show that the overall potential activity of urease and catalase was at its highest during the winter season.
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Microbial communities and carbon cycling in subglacial ecosystems and their analogues
Rybár, Marek ; Stibal, Marek (advisor) ; Řeháková, Klára (referee)
Subglacial environments are located at the interface of glacier ice and bedrock. They represent one of the major ecosystems associated with glaciers and ice sheets. They contain liquid water and fine material including organic matter, accumulated during periods of glacier advance. It is well established that there are active microbial communities residing in these environments, which are adapted to living in extreme conditions. Subglacial ecosystems are mostly isolated from the atmosphere and thus their oxygen content is usually very low. Therefore, the organisms residing in these environments often employ anaerobic/anoxic strategies to ensure their survival. However, knowledge of these communities is limited due to practical constrains associated with subglacial ecology and biogeochemistry research. The activity of microorganisms beneath glaciers significantly influences carbon cycling. In recent years, this ecosystem is dynamically changing and may have important impact on regional and global carbon cycle. Therefore, it is important to better understand this ecosystem. This thesis summarizes recent knowledge of microbial communities and carbon cycling in this ecosystem and discusses suitable analogues, which could help us understand the fascinating subglacial ecosystem and formulate future research...
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Microbial activity of deep subsurphace miocen sediments near Soklov
Galertová, Renata ; Frouz, Jan (advisor) ; Kryštůfek, Václav (referee)
In my diploma thesis I observed microbial activity in Miocene sediments collected at two different depths - 30 and 150 meters - in the "Družba" open-mine pit, which is located in Sokolov Brown Coal Basin. There were three different types of sediment: lamellar, amorphous and transitional. Samples were obtained under sterile conditions and following treatments were applied to the transitional sediment: addition of glucose, wetting and freezing. The aim of my study was to observe the activity of the original microflora at various depths and the impact of environmental factors that can affect the quarried claystones after being put on heaps. Microbial activity was evaluated by measuring released CO2 (titration). Obtained values of microbial activity did not show any differences between the respiration of sediments of different ages (depths), but differences between different types of sediments were significant, the highest values were found in lamellar sediment. Affection of samples then showed biota activity response suggesting that microbial communities at lower depths are limited by nutrients. Because the application of glucose did not show any noteworthy effect, we can assume that these communities are specialize on present fossil organic matter they are able to decompose, which is important especially in...
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Rozdíly mezi mikrobiálními aktivitami rhizosférní a nerhizosférní půdy
Trčková, Nikola
The bachelor's thesis presents basic findings of soil -- its formation and importance, essential functions, physical and chemical properties and composition. Further issues described are organic matter, soil humus and cycles of major elements. Particular importance is dedicated to the rhizosphere, microorganisms and their microbial activity on rhizosphere and non- rhizosphere soil. Based on the microbiological analysis of rhizosphere and non- rhizosphere soil, the count of significant physiological groups of microorganisms is determined. The results are compared and evaluated.
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