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The effect of selected endocrine disruptors on cytochromes P450 1B1 and 3A1/2
Holecová, Jana ; Bořek Dohalská, Lucie (advisor) ; Cajthaml, Tomáš (referee)
Many exogenous and endogenous compounds are referred to as endocrine disruptors (EDCs), as they interfere with natural synthesis, signaling and metabolism of endogenous hormones. Common exogenous endocrine disruptors are benzo(a)pyrene (BaP) and 17α-ethinylestradiol (EE2). Endogenous endocrine disruptor 17β-estradiol (E2) is frequently present in the environment as well. In this thesis, the effect of the mentioned EDCs and their combinations on gene and protein expression of CYP1B1, 3A1 and 3A2 in rat liver, kidney and lung was determined. Protein expression was studied using Western blot method and specific antibodies; gene expression was assessed by quantitative PCR. Moreover, the effect of tested EDCs and their combinations on BaP metabolism and CYP3A specific activity (measured as testosterone 6β-hydroxylation) were studied in liver microsomal samples. It was confirmed, that BaP significantly increases CYP1B1 expression in rat liver and lung both alone and together with EE2 or E2. Pretreatment of rat with E2 and BaP increases the ability of BaP to induce CYP1B1 expression. On the contrary, EE2, E2 and their combination decrease the CYP1B1gene expression. The rate of BaP metabolites formed in liver microsomal samples increases in rats pretreated with BaP and its combinations. In liver, there was...
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Biodegradation of selected psychopharmaceuticals in underground water using Pleurotus ostreatus
Krejčová, Lucie ; Cajthaml, Tomáš (advisor) ; Pivokonský, Martin (referee)
The ability of the ligninolytic fungus Pleurotus ostreatusto degrade 4 pharmaceutical drugs and 5 compounds which are either used during drug manufacturing or are created as by-products was studied. These compounds were detected in groundwater near a drug manufacturing plant. The maximum concentration levels of the selected compounds in tested groundwater samples variedfrom0.23 µg/lto 227.87 µg/l apart from 1 compound which was not detected in any sample. The degradation efficiency of P. ostreatus was examined with individual compounds as well as with the mixture of all 9 compounds. When degrading individual compounds P. ostreatus lowered the initial concentration (10 mg/l) of 5 compounds by 62-100% after 14-day cultivation in malt extract-glucose medium. When degrading the compound mixture P. ostreatus lowered the initial concentration (2 mg/l of each compound) of 5 compounds by 50-100% after 14-day cultivation in malt extract-glucose medium. Acute toxicity tests with Vibrio fischeri suggest the formation of metabolites which are more toxic than the original compounds. The EC50 value for individual compounds during toxicity tests with Vibrio fischeri was 5.45-131.98 mg/l. Keywords:biodegradation, pharmaceuticals, ligninolytic fungi, Pleurotus ostreatus, groundwater, toxicity, Vibrio fischeri
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Influence of microbial community diversity on the decomposition of organic matter
Vicena, Jakub ; Frouz, Jan (advisor) ; Cajthaml, Tomáš (referee)
Microbial diversity plays an important role in the decomposition of soil organic matter. However, the drivers of this dependence still remain unclear. The work is based on long-term monitoring of soils of different successional stages of different diversity. Soil sampling was conducted on two dumps after brown coal mining in the Sokolov. Soils were X ray sterilized and inoculated by inoculum from both soils in two inoculation density which create gradient of microbial diversity. Then microbial respiration was measured in either supplied or not supplied by litter of Calamagrostis epigejos. Results showed a strong positive correlation between the microbial diversity and decomposition of organic matter if the microbial community is limited by available carbon. If there isn't carbon limit available, the decomposition rate is controlled by the amount of microbial biomass. Results demonstrated positive correlation between the rate of decomposition and the amount of fungal biomass. The soils with the addition of leaf litter showed priming effect in the initial stage of decomposition. In the control samples without addition of litter priming effect wasn't observed. Increasing humidity led to increase of decomposition rate. We can conclude with a clear conscience that similarly conclusive results associated...
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Biodegradation of polychlorinated biphenyls in underground water using biological approaches.
Šrédlová, Kamila ; Cajthaml, Tomáš (advisor) ; Innemanová, Petra (referee)
Polychlorinated biphenyls (PCBs) are a class of important organic pollutants which undergo very slow degradation and tend to persist for a long time in the environment. PCBs have various negative effects on living organisms, human health and the environment in general. A method for determining PCB levels in aqueous matrices was developed consisting of solid-phase extraction (SPE) and GC/MS determination. The average recoveries of PCB congeners from artificially spiked deionized water were around 85%. The PCB concentration of 3.3±0.1 μg·l-1 (a sum of selected congeners) was detected in contaminated groundwater originated from the area of a former asphalt concrete producing plant. The most abundant PCBs were trichlorinated congeners which together comprised about 80% of the total PCB content. The optimised SPE method was further applied together with accelerated solvent extraction (ASE) to assess the degradation potential of oyster mushroom (Pleurotus ostreatus) which shows high degradation efficiency of various organic pollutants including PCBs. P. ostreatus belongs to ligninolytic (white-rot) fungi, which is a very promising group of microorganisms frequently studied due to their bioremediation potential. P. ostreatus, strain KRYOS was able to remove 41±8% of the initial amount (50 μg) of the...
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Study of main mycoremediation aspects - effect of bioavailability, biodegradation and toxicity of organic pollutants
Čvančarová, Monika ; Cajthaml, Tomáš (advisor) ; Kočí, Vladimír (referee) ; Bosáková, Zuzana (referee)
Many organic compounds are released to the environment and can be harmful to living organisms. These compounds are often persistent and toxic. Some are mutagens, carcinogens, endocrine disruptors or they can cause an increase in bacterial resistance. They tend to accumulate in nature and their transformation is a long-term process. Therefore, various remediation techniques are needed for decontamination. Remediation and bioremediation processes depend on many factors which should be critically evaluated. This dissertation thesis studies the relationship between bioavailability, biodegradation and toxicity of polychlorinated biphenyls, polycyclic aromatic hydrocarbons and fluoroquinolone antibiotics. These compounds of different origin, character and properties were degradated by ligninolytic fungi. Desorption behaviour of pollutants from historically contaminated sites, degradation potential of ligninolytic fungi, ongoing degradation mechanisms, transformation products and their toxicity were studied as important factors for evaluation of mycoremediation and its environmental impact. The results show that determination of bioaccessible fraction by sequential supercritical fluid extraction is very useful for precise prediction of biodegradability of pollutants. The evidence that ecotoxicity and...
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Impact of litter quality on decomposition
Vicena, Jakub ; Frouz, Jan (advisor) ; Cajthaml, Tomáš (referee)
The text of the thesis is divided into two parts. The literature overview discusses the importance of decomposition to carbon cycling in soils and evaluation of biological, physical and chemical factors that affect decomposition. To understand the factors affecting the soil respiration is essential to improve the global carbon balance. Decomposition affects also the release of nutrients, soil fertility and other soil processes and properties. The very project aims at the impact of leaf litter quality assessment (specifically, the C: N: P ratio) on the rate of decomposition. The assumption is that the low C:N ratio initially accelerates the decomposition which quickly reaches its minimum. Conversely, at a high C: N ratio the rate of decomposition is initially slower and subsequently reaches its minimum, and the average value of decomposition will be higher than in samples with low C:N ratio. For litter which has undergone leaching phase none of the significant differences in respiration of the individual samples with different C:N were statistically proved.
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Optimization and application of assays for determination ecotoxicity of nanomaterials
Semerád, Jaroslav ; Cajthaml, Tomáš (advisor) ; Kočí, Vladimír (referee)
This thesis deals with optimization and application of assays for determination of ecotoxicity of nanomaterials based on nanoscale zero-valent iron (nZVI), which are used in remedial technologies. After in situ application of nZVI, a significant decrease in toxicity of polluted environment was detected; however, a potential negative effect of nanoparticles has not been sufficiently investigated yet. Standard used tests were found to be incompatible with nZVI for toxicity determination. Specific characteristics of nZVI, such as high reactivity and sorption, complicate determining the toxicity by routinely used ecotoxicity tests. Concentration ranging from 0,1 to 10 g/l that are used in practise for decontamination were tested. These concentrations resulted in formation of turbidity, which prevented the use of standard tests. In this work, a new method has been optimized for in vitro toxicity testing of nZVI and derived nanomaterials using bacteria. The principle of this assay is determination of oxidative stress (OS). The disbalance between formation and degradation of reactive oxygen species (i.e. OS) leads to irreversible changes in biomolecules of organisms and formation of undesirable products. A toxic and mutagenic product - malondialdehyde (MDA) is formed during lipid peroxidation and it is a...
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Modern Trends in High Performance Liquid Chromatography and Their Application
Kozlík, Petr ; Bosáková, Zuzana (advisor) ; Pacáková, Věra (referee) ; Cajthaml, Tomáš (referee)
(EN) The dissertation thesis is focused on major trends in high performance liquid chromatography such as miniaturization of separation systems in hyphenation with high- sensitivity detection or characterization of new types of stationary phases for the separation of polar compounds in systems suitable for mass detection. Application of recently developed stationary phases in hydrophilic interaction liquid chromatography (HILIC) is also considered. Capillary liquid chromatography with tandem mass spectrometry (cLC-MS/MS) method was developed for determination of five estrogenic pollutants in samples of water. Several new sorption materials for solid phase extraction (SPE) were compared to obtain sufficient recovery of all the tested analytes. Discovery DSC-18Lt column provided the highest recovery (95 - 100 %). The optimized cLC-MS/MS with SPE was used for determination of estrogens in water samples in the order of units to tens of ng/L. HILIC separation systems with silica gel, cyclofructan and isopropyl cyclofructan modified silica stationary phases were tested and compared. Ability to donate protons and dispersion interactions are the main interactions that affect retention in HILIC with cyclofructan-based columns while they are less important in separation systems with bare silica stationary...
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Bioremediation of persistent aromatic pollutants
Stella, Tatiana ; Cajthaml, Tomáš (advisor) ; Mihaljevič, Martin (referee) ; Tesařová, Eva (referee)
The remediation of persistent chlorinated aromatic compounds has become a priority of great relevance due to the teratogenic, carcinogenic and endocrine-disrupting properties of these xenobiotics. The use of biological methodologies for the clean-up of contaminated sites, collectively referred to as "bioremediation", has been gaining an increasing interest in recent years because it represents an effective, cost-competitive and environmentally friendly alternative to the physico-chemical and thermal treatments. In this respect, "white rot" fungi, an ecological subgroup of filamentous fungi, display features that make them excellent candidates to design an effective remediation technology ("mycoremediation"). In spite of this, fungi have not been widely exploited for their metabolic capabilities and the mechanism by which they are able to degrade the aforementioned pollutants has not been fully elucidated yet. Within this frame, the present Ph.D thesis was aimed at: i) assessing the efficiency of different mycoremediation strategies for the clean-up of a polychlorinated biphenyl (PCBs)-contaminated soil; ii) understanding the fungal degradation pathways of polychlorinated biphenyls and their major metabolites, namely chlorobenzoic acids (CBAs) and hydroxylated polychlorinated biphenyls (OH-PCBs). i)...
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Fungal Biodegradation of Endocrine Disruptors
Křesinová, Zdena ; Cajthaml, Tomáš (advisor) ; Macek, Tomáš (referee) ; Smrček, Stanislav (referee)
This dissertation thesis contains scientific results attained in the field of bioremediation. The major part of the results has been published in international journals in 7 papers. In addition, relevant yet unpublished results have been included too. The first thematic part describes the screening of the degradation ability of white rot fungi (WRF). In the screening, several endocrine-disrupting compounds (EDs; bisphenol A, triclosan, 4-nonylphenol and 17α-ethinylestradiol) were degraded by 8 different fungal strains in the presence of liquid medium. The most promising strains were used for the degradation of an ED mixture (synthetic and natural estrogens) in the presence of a straw substrate. Attention was paid to the evaluation of stimulation or suppression of enzyme activities during the biodegradation processes and changes in residual estrogenic activity. Pleurotus ostreatus, Irpex lacteus and Trametes versicolor showed the highest degradation ability under both cultivation conditions. On the contrary, Phanerochaete chrysosporium, to date the most studied representative of white rot fungi, did not degrade bisphenol A and 17α-ethinylestradiol (EE2) at all. Two review articles have been published to summarize the origin, presence and biodegradation of EDs, mainly EE2, in the environment. The...
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