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Study of the occurrence of colistin in soil
Veldamonová, Aneta ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
Colistin is a polypeptide antibiotic used as a "last resort" effective against Gram-negative bacteria. However, increase in its consumption in veterinary medicine in the last 30 years has led to the development of bacterial resistance even to colistin. The application of slurry to soil containing unmetabolized colistin and resistant bacteria poses a risk, because the resistance of bacteria to colistin can be further developed and spread to other components of the environment. Therefore, this work was focused on the creation and optimization of extraction and analytical methods for soil samples containing colistin. Colistin was detected by liquid chromatography in connection with mass spectrometry (HPLC/MS and UPLC/MS/MS). Many extraction solutions have been tested in connection with ultrasonic extraction and purification on various SPE columns, yet colistin has not been successfully extracted from the soil. Colistin was successfully detected only in the slurry extract. The reason why colistin was not detected in soil extracts could be the sorption of colistin on soil organic matter or the formation of complexes of colistin with humic substances.
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Analysis of fluoroquinolone antibiotics in the soil
Vdolečková, Monika ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
The thesis dealt with the global problem of the occurrence of pharmaceuticals in the environment, specifically fluoroquinol antibiotics (ciprofloxacin and enrofloxacin), which are among other critically important antibiotics. These drugs enter the soil environment through the application of already contaminated animal waste (e.g. manure) or through wastewater used in irrigation or through the application of treated sewage sludge, which may contain drug residues. Increasing concentrations of these antimicrobial drugs in the environment provide an environment for the emergence and spread of microbial resistance. The accumulation of these drugs then leads to the emergence of resistance to these antibiotics. The experimental part of the thesis focused on the optimization of a method for the extraction and subsequent determination of fluoroquinolones in soil and litter. For this purpose, parameters related to the extraction yield of fluoroquinolones from the soil matrix were optimized, such as sample weighting, selection of a suitable extraction medium, SPE performance, elution method from the SPE, etc. Extraction recoveries of 70 to 140 % were achieved as part of the optimization. Finally, the optimised method for extraction of fluoroquinolones from poultry litter and soil samples provided by the ÚKZÚZ was used. The experimental results confirm the long-term persistence of these drugs in the environment.
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Music information retrieval techniques for determining the place of origin of the Czech chamber and orchestral music interpretations
Miklánek, Štěpán ; Mekyska, Jiří (referee) ; Kiska, Tomáš (advisor)
This diploma thesis is focused on the statistical analysis of chamber and orchestral classical music recordings composed by Czech authors. One of the chapters is dedicated to the description of a feature extraction process that precedes the statistical analysis. Techniques of Music Information Retrieval are used during several stages of this thesis. Databases used for analysis are described and pre-processing steps are proposed. A tool for synchronization of the recordings was implemented in MATLAB. Finally the system used for classification of recordings based on their geographical origin is proposed. The recordings are sorted by a binary classifier into two categories of Czech and world recordings. The first part of the statistical analysis is focused on individual analysis of features. The features are evaluated based on their discrimination strength. The second part of the statistical analysis is focused on feature selection, which can improve the overall accuracy of the binary classifier compared to the individual analysis of the features.
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Isolation of pure aminoacids from wheat bran
Sloupová, Klára ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
Wheat bran is a promising material containing a wide range of useful components, including proteins. In addition, it is produced in significant volumes. Currently, wheat bran is used for the production of energy by combustion and for feed purposes. Gradually, new methods of valorization of this material are being sought. One of the possibilities of using wheat bran is the isolation of proteins, hydrolysis, and separation of selected amino acids. This diploma thesis deals with this issue, it is focused on the recovery of arginine and leucine from a protein isolate. Proteins were extracted from wheat bran by changing the pH. Thanks to the subsequent lyophilization a protein isolate was gained. Prior to hydrolysis of the resulting isolate, a stability test of arginine and leucine amino acid standards was first performed, to which various hydrolysis methods were applied. Acid hydrolysis using a mineralizer, which was applied to the protein isolate, was proved to be the most effective. This was followed by the derivatization of the hydrolysates with OPA and analysis of the resulting hydrolysates by high-performance liquid chromatography with UV-VIS detection. Then, suitable adsorption and desorption conditions were optimized. It was found that the time dependence does not affect the amount of adsorbed material on the sorbent. Therefore, an application time of 15 minutes was chosen. While optimizing the amount of used standard, it was found that the optimal weight was 0.25 g of sorbent. The selected conditions were applied to the protein hydrolyzate. Two fractions were obtained by the separation of selected amino acids due to the change in the pH of the citrate buffer. After the application of this procedure, 0.26 g of arginine and 0.82 g of leucine were obtained from one kilogram after evaporation. From evaporation two, 1.01 g of arginine and 0.25 g of leucine were obtained after evaporation.
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Rhodium in the environment
Ondreášová, Klára ; Nevrlá, Jana (referee) ; Komendová, Renata (advisor)
This bachelor thesis focuses on the characteristic of rhodium, its use in the automotive industry, the occurrence in environmental compartments (air, soil, vegetation, water), accumulation and transformations. In this thesis there are also described methods of sampling for determination, the types of sample preparation, separation and preconcentration techniques necessary prior to instrumental analysis. The work also focuses on the most commonly used analytical methods of rhodium determination, which are spectrophotometric methods, AAS, ICP-AES and ICP-MS.
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Study and characterization of organic substances in a biochar sample
Vojáčková, Beáta ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis characterizes biochar from a physico-chemical point of view. The theoretical part deals with biochar as a soil conditioner, its properties, use, production, and last but not least, effect of its sorroundings. For better characterization of organic and inorganic matter a phosphate buffer was used. This buffer ensures their specific extraction due to a neutral pH. The second path is to use rainwater, which simulates the condition of the soil environment. In the experimental part are discussed both; purified buffer-extracted samples and rainwater samples, which were studied by thermogravimetric analysis (TGA), elemental analysis (EA) and by infrared spectroscopy with Fouier transform (FTIR-ATR). Conductivity and pH were also measured. Moisture and ash content, which represent the inorganic non-combustible fraction, were determined using thermogravimetry. The extraction yields were converted to ashless wt. % based on these values. Results of EA provided us with information on the content of biogenic elements and basic physico-chemical characteristics of biochar. In contrast, the FTIR method defined the presence of individual functional groups and specific constitutive units, which are present in the extracts. This information allows us to better understand the environmental impact of biochar on the soil ecosystem.
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Isolation, characterization and application of biomedically important polymer P(3HB-co-4HB)
Krupičková, Kristýna ; Přikryl, Radek (referee) ; Obruča, Stanislav (advisor)
This diploma thesis deals with the isolation and characterization of copolymer P(3HB-co-4HB). The teoretical part was prepared as a literature search which describe polyhydroxyalkanoates in general, their structure, synthesis, degradation and isolation. Furthermore, copolymers containing 4HB units are mentioned in this thesis and there is also no mentioned of the biosynthesis and biodegradation of copolymer P(3HB-co-4HB). The first aim of this diploma thesis was to find out which solvent is the best for copolymer extraction and then characterize obtained copolymer P(3HB-co-4HB). The isolated copolymer was characterized by gas chromatography, SEC-MALS, thermal analysis and SEM. In the second part of the thesis, release of model biologically active substance from the PHA films was studied. Rhodamine 6G dye was selected for the simulation, which was used to stain the copolymer films and the P(3HB) films. It was observed that film prepared from P(3HB-co-4HB) copolymer released entrapped substance much faster than film made from P3HB homopolymer, and, in addition, the copolymer was substantially more susceptible to enzyme degradation.
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Obtaining and complex charaterization of Aronia spp. extracts
Seidlová, Kateřina ; Zemanová, Jana (referee) ; Veselá, Mária (advisor)
Aronia (Aronia melanocarpa) is a berry fruit with distinctive sensory characteristics and health-promoting properties. Polyphenols are the main bioactive compounds found in aronia including natural pigments – anthocyanins. Bioactive compounds are usually obtained from natural materials by extraction, in this work, two methods of extraction were compared – maceration and PHWE. Based on the total phenolic content, maceration was chosen as a more suitable method and then was optimized with statistical model – Design of Experiment. Optimal conditions were set to temperature of 30 °C, extraction agent 50 % ethanol, solid-solvent ratio 10 g per 50 ml and time of extraction for 30 minutes. Extract obtained under these conditions was characterised by total phenolic content – 1441 ± 90 mg/100 g DW, total anthocyanin content 943 ± 8 mg/100 g DW and antioxidation activity by ABTS 24,78 ± 0,09 molTE/g. In total of 25 volatile compounds were indentified in the optimal extract with content > 0,5 %. Major part created aldehydes and esters, with the main compounds being benzaldehyde (32,25 %) and methyl hexanoate (21,37 %).
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Extraction of bioactive substances from black currant pomace
Sedláčková, Lucie ; Štursa, Václav (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with extraction of bioactive substances from black currant pomace (Ribes nigrum). The theoretical part contains the botanical characteristics of the plant species Ribes nigrum. It is also devoted to the biologically active substances contained in black currant and possibilities of using black currant in the food industry. The fourth chapter deals with description of phenolic compounds, their distribution and methods of determination of phenolic substances. The fifth chapter describes selected extraction procedures. In the experimental part, there were extracted dry black currant pomace in order to optimize the extraction process and obtain the highest yields of dyes. In addition, were determined the selected chemical and physical characteristics of blackcurrant juice and extracts from blackcurrant pomace. A better solvent was a mixture of water and ethanol in a volume ratio of 1:1. After 14 hours maceration of dry pomace, were obtained 769,9 mg anthocyanins per 100 g of dry material.
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