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Dynamics and structure of diatom communities in glacier and/or groundwater-fed streams.
Prüherová, Alžběta ; Kulichová, Jana (advisor) ; Žárský, Jakub (referee)
Alpine streams and their algal communities have been increasingly challenged in recent years by the effects of climate change, particularly associated with glacier retreat and their melting. Glaciers in particular are an important hydrological source for alpine ecosystems, which are threatened by rising temperatures, that are more influential in these areas than at lower altitudes. Due to the ongoing retreat of glaciers, glacier meltwater is increasingly being added to tributary streams. This glacier water has significantly different characteristics and may thus be a significant contributor to changes in the diatom biodiversity of alpine aquatic ecosystems. The manipulated experiment of this thesis took place from July to September 2020 in the Swiss Alps. Using permanent diatom slides created out of samples taken from the experimental channels, changes occurring when glacier meltwater was added to ground water-fed tributary streams and changes occurring when ground water was added to glacier-fed streams were analysed. Changes in diatom abundances were compared with environmental factors such as temperature, pH, turbidity or conductivity. Glacial streams were characterised by significantly lower temperature, higher values of conductivity and turbidity, higher oxygen saturation and also higher pH...
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Role of microbes in the decomposition in headwater streams.
Kociánová, Petra ; Kopalová, Kateřina (advisor) ; Tátosová, Jolana (referee)
The decomposition of organic matter in headwater streams is a key process in stream ecology and an important component of the global carbon cycle. Decomposition rates depend on both abiotic and biotic factors, the former including temperature, discharge, and nutrient chemistry, and the latter including stream community structure and activity, trophic interactions, biodiversity, and productivity. Of the stream community, microbial decomposers play a particularly important role in decomposition by chemically degrading compounds and transferring nutrients and energy to higher trophic levels. These processes are prone to change due to current and future global warming which will affect both decomposer communities and associated decomposition rates. This thesis provides a short overview of the main factors that control stream decomposition rates, including biological factors like microbial activity, abiotic factors such as water temperature and nutrient availability, and how these factors may be altered in the future under a warmer climate. Specifically, I predict that climate change will increase microbial activity and decomposition in headwater streams due to increased water temperatures, changes in surrounding vegetation, and shifts in the hydrological regime due to global warming. .
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Biodegradation of new types of lightweight polyurethanes in different environmentally-relevant microcosms
Hušek, Pavel ; Innemanová, Petra (advisor) ; Cajthaml, Tomáš (referee)
Presented diploma thesis focuses on a new type of lightweight polyurethane foam (PUR), which has been manufactured with the intention of it being biodegradable within currently valid norms on biodegradation of plastic materials. The future use of said polyurethane foam is as carrier for odor repellent to avoid wildlife-vehicle collisions in agriculture landscape, where, after the end of its lifespan it could be left to biodegrade in soil the environment. The examined material, PUR BIO-10, was tested for biodegradability in laboratory microcosms according to standardized method ASTM D5988-03. Biodegradability was tested in two separate soil types - forest soil and agricultural soil, which have been selected with the future use of the material in mind. According to the method biodegradability was measured as mineralization of the material by capturing evolved carbon dioxide. Two trials with different treatments were executed. In the first trial the material was introduced directly into the soil and in the second trial the material was tested in a litterbag to avoid soil contamination which was problematic for further analysis. During the first trial, after 90 days, the mineralization of polyurethane foam was 10.65 ± 2.54 % in the forest soil and 20.48 ± 9.18 % in the agricultural soil. During the...
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Biodegradation of new types of lightweight polyurethanes in different environmentally-relevant microcosms
Hušek, Pavel ; Innemanová, Petra (advisor) ; Cajthaml, Tomáš (referee)
Presented diploma thesis focuses on a new type of lightweight polyurethane foam (PUR), which has been manufactured with the intention of it being biodegradable within currently valid norms on biodegradation of plastic materials. The future use of said polyurethane foam is as carrier for odor repellent to avoid wildlife-vehicle collisions in agriculture landscape, where, after the end of its lifespan it could be left to biodegrade in soil the environment. The examined material, PUR BIO-10, was tested for biodegradability in laboratory microcosms according to standardized method ASTM D5988-03. Biodegradability was tested in two separate soil types - forest soil and agricultural soil, which have been selected with the future use of the material in mind. According to the method biodegradability was measured as mineralization of the material by capturing evolved carbon dioxide. During the first trial the mineralization of polyurethane foam was 10.65 ± 2.54 % in the forest soil and 20.48 ± 9.18 % in the agricultural soil. During the second trial the mineralization was 3.88 ± 3.42 % in the forest soil and 8.96 ± 1.79 % in the agricultural soil. In the second trial the difference between the soils was statistically significant. After the end of the biodegradation experiments the tested material was...
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Assembly, successional development and functioning of microbial communities in deadwood
Bernardová, Natálie ; Brabcová, Vendula (advisor) ; Kopecký, Jan (referee)
Dead wood is one of the most important reservoirs associated with forest ecosystems. In natural forests, its volume is counted in hundreds of m3 ha-1 , whereas it reaches only tens of m3 ha-1 in productive commercial forests. In contrast to soil and plant litter, deadwood is unevenly distributed on the forest floor. The specific physicochemical properties such as high content of recalcitrant polymers, low nitrogen level and impermeability negatively affect the rate of decomposition especially in the initial stages of wood deconstruction. The deadwood decomposition is very slow in comparisons with other substrates, it accumulates and thus it represents the important reservoir of nutrients. This thesis is focused on the structure, development and function of microbial (fungal) community in decomposing deadwood in unmanaged forest. Functional screening of fungi isolated from fruit bodies collected from coarse deadwood was set aside. Physico-chemical properties of deadwood including pH, carbon and nitrogen content and microbial biomass were estimated for four wood decomposition stages and three different tree species. New generation sequencing (Illumina MiSeq platform) was applied for fungal community structure analysis based on ITS2 fragment. Fungal functional screening was based on physico-chemical...
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Utilization of phospholipid fatty acids analysis for biodrying study
Stránská, Štěpánka ; Cajthaml, Tomáš (advisor) ; Innemanová, Petra (referee)
The aim of this thesis is the utilization of phospholipid fatty acids (PLFA) analysis to determine groups of microorganisms present during the biodrying of sewage sludge and their description in relation to the temperature regime of the biodrying. Four experimental cycles A, B, C, D were followed. Cycles A, B and C, D differred from each other in the sewage sludge collected from two waste water treatment plants. The cycles A, B, C and D were each performed in two reactors with different aeration regimes to compare the mesophilic (max. temperature ±50 řC) and thermophilic (max. temperature ±70 řC) regimes of biodrying. PLFA analysis was used to determine the microbial groups. Concentrations of individual PLFA were subjected to principal component analysis (PCA). The total PLFA concentration corresponding to total microbial biomass was decreasing during both temperature regimes of cycles B, C, D, while the total PLFA concentration increased towards the end of both temperature regimes of cycle A. The total PLFA concentration reached statistically higher values at the end of the mesophilic regime of cycles B, C and D. The development of fungi to bacteria ratio showed that fungi applied more with the progression of both temperature regimes of cycles A, B and the thermophilic regime of cycle C. Based on...
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Use of microbial community structure as a marker of conditions in underground biotops
Burkartová, Kateřina ; Falteisek, Lukáš (advisor) ; Drahota, Petr (referee)
The amount of data obtained by barcoding of prokaryotic 16S rDNA from natural habitats is increasing exponentially. Thus, methods enabling us to extract useful information from these data are of increasing importance. In this thesis microbial communities from water, sludge and drilling dust were analyzed by 16S rDNA sequencing in three geologically well described sedimentary aquifers in Bohemian Massif. The main goal of this research was to establish how different analytical approaches can be useful in interpretation of groundwater biogeochemical processes. Three approaches were used: First, taxonomy and metabolic traits of the most abundant microorganisms were assessed. Second, ordination methods showing metabolic and taxonomic variability between communities were used. Last the analysis of phylogenetic dissimilarity using UniFrac metrics was performed. When analyzing individual localities separately, the shift in microbial community composition corresponds with the change of environmental conditions. The unconstrained ordination method based on the variability in metabolic traits indicated, that sludge samples are more informative than water samples when asking which electron donor is used in microbial communities. On the other hand, unconstrained ordination methods were useless when the...
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