National Repository of Grey Literature 436 records found  beginprevious199 - 208nextend  jump to record: Search took 0.00 seconds. 
Production of Selected Yeast Metabolites Applicable to Food Supplements
Němcová, Andrea ; Čertík, Milan (referee) ; Vávrová, Milada (referee) ; Márová, Ivana (advisor)
Carotenoids are naturally occurring pigments of plants also produced in many bacteria, and fungi. They represent one of the widest group of natural antioxidants with significant biological effects and numerous of industrial applications. There is an increased interest in carotenoids as natural antioxidants for their ability to reduce chronic diseases, various pathological stages and aging. The area of their application concerns mainly food industry; however, they are used in chemical, pharmaceutical, and cosmetics industry as well. One possibility is study of potential of red yeasts that are able to convert various substrates into carotenoid pigments. In presented thesis carotenogenic yeast belonging to the genus Rhodotorula, Sporobolomyces and Cystofilobasidium were tested for ability to use of selected waste substrates and also random mutagenesis in order to increase the production of biomass and specific metabolites – carotenoids and other lipid-soluble substances. As alternative nutrient sources derived from waste substrates from agricultural and food production (rapeseed substrate, rice, wheat, apple fiber, pasta and lignocellusic materials) were tested. To selected production media extracellular hydrolytic enzymes or commercial enzymes degrading polysaccharide were added. All tested red yeast strains were able to utilize these substrates as the only carbon source and simultaneous produce carotenoid enriched biomass. In this work, characterization of carotenogenic yeast using molecular techniques was studied. For this usage, interspecific variables of strongly conserved sequences of genomic DNA, especially rDNA D1/D2 large ribosomal subunit and ITS1 and 5,8-ITS2 rDNA regions were amplified. These sequences were subjected analysed by DGGE method to compare differences of carotenogenic yeasts. Isolation procedure of the intact DNA were optimized for caryotypic yeast characterization by pulsed field gel electrophoresis (PFGE). The karyotype of tested yeasts contain visible differences between yeast species and genera.
The Introduction of Contact Ecotoxicity Tests for the Assessment of Terrestrial Ecosystems
Modlitbová, Pavlína ; Kráčmar, Stanislav (referee) ; Beklová, Miroslava (referee) ; Demnerová, Kateřina (referee) ; Vávrová, Milada (advisor)
This dissertation thesis is focus on using toxicity tests with testing organism - terrestrial isopod Porcellio scaber. This organism is use for toxicity assessment of selected anorganic compunds which could contaminate terrestrial ecosystem. This organism was selected for several reasons - sophisticated test methodology; well known biology of these animals and their ecological relevance. Besides classical endpoints such as mortality, change in mass of test specimens and the effect of the presence and concentration of contaminants onto food consumption; we monitored changes in the morphometric characteristics at the level of tissues and cells, the cytotoxicity and possibly bioaccumulation in various parts of the body of the organism. Selected test substance in this thesis were nanoparticles and inorganic salts. Wherein for chosen gold nanoparticles was carried out a complete study presents several levels of organization of living matter (organism, tissue, cell). For selected salts compound, this study was carried out on the behavior of organisms and classical endpoints.
Dissolved Air Flotation – From Pilot Plant to Full Scale Implementation
Dobiáš, Pavel ; Hlaváč, Jaroslav (referee) ; Janda,, Václav (referee) ; Vávrová, Milada (referee) ; Dolejš, Petr (advisor)
The thesis deals with the use of dissolved air flotation (DAF) in water treatment technology in the Czech Republic. It summarizes the knowledge gained at pilot plant studies as well as the experience with full-scale flotation units which have been built in potable water treatment plants in the Czech Republic in years 2006-2018. This thesis provides a broad background of experimental studies of a modern separation process, which does have great advantages in the removal of natural organic matter and microorganisms from water in the drinking water treatment industry. In this thesis, there are presented some examples of the excellent efficiency of the microorganisms removal, both under the experimental conditions as well as water treatment plants, which were improved by DAF units installation in full scale. In addition to the high separation efficiency, it is shown, how DAF units could influence the subsequent separation steps as for example filtration through the granular media. The negative influence of the pre-ozonization on the DAF separation efficiency in Hradec Králové WTP is demonstrated too. The results of the pilot experiments support the idea, that the key condition for high removal efficiency is the optimal coagulation process chemistry. Design of pilot experiments was based on the factorial planning theory and some results are discussed in this thesis. The very big portion of the pilot experiments was made for estimating of the full-scale DAF design parameters before the water treatment plants reconstruction phase
Hormones in sewage sludge
Jagošová, Klára ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
Currently there is a spate of interest in the presence of pharmacologically active substances in the environment. These substances are excreted in active or metabolized form and with wastewater pass the wastewater treatment plant. Current treatment technologies do not always eliminate all pharmaceuticals effectively and therefore they enter the environment. One of these active groups is the group of steroid hormones. Steroid hormones belong to the group of endocrine disruptors and they are considered to be dangerous for the ecosystems. Due to the hydrophobic character of steroid hormones they undergo partial or total sorption from wastewater to sludge. Sewage sludge is the by product of wastewater treatment and contains heavy metals, organic contaminants and pathogenic bacteria. A part of produced sewage sludge is used as a fertilizer in the Czech Republic. This issue follows the regulation 347/2016 – conditions of agricultural use of sewage sludge. Waste policy of EU will alter the conditions of sludge disposal, so it is necessary to obtain data about the concentration levels, fate and behaviour of those pollutants. This thesis was focused on five natural female hormones and four synthetic, which are used as a part of contraceptive pills and substitutional hormonal therapy. Determination of hormones was performed in four steps including ultrasonic assisted extraction, clean up by solid phase extraction, derivatization and final analysis by gas chromatography with mass spectrometry on triple quadrupole in MS/MS mode.
Application of gas chromatography for determination of drug residuals
Sýkora, Richard ; Lisá, Hana (referee) ; Vávrová, Milada (advisor)
Analgesics are nowadays widely used group of drugs in human and also in veterinary medicine. Residuals of these drugs enter surface waters via discharges from the waste water treatment plants as the result of insufficient efficiency of their removal during cleaning process. In this bachelor thesis the possibilities of the analgesics residuals determination in waters using derivatization followed by gas chromatography with mass spectrometric detection were experimentally evaluated. Individual derivatization procedures were compared too. Several derivatization agents were tested and experimental parameters for selected analgesics were optimized (reaction time and temperature, amount of derivatizing agent). Further, several procedures of isolation of target compounds from water based on Solid Phase Extraction were verified. In all cases, gas chromatography with TOF-based mass spectrometric detection acts as final analytical method.
The environmnetal impact of burning products
Ročňáková, Ivana ; Vávrová, Milada (referee) ; Doležalová Weissmannová, Helena (advisor)
The submitted thesis deals with the study of combustion products and their impact on the environment and human organism. It explains the nature of combustion and conditions under which the fire originates. In this action is developed a large number of different substances. As concrete examples of inorganic substances were selected following compounds: carbon monoxide, carbon dioxide, sulfur dioxide, sulphates, hydrogen chloride, hydrogen cyanide, nitrous gases and ammonia. From the organic compounds were selected only a few examples, such as the burning of plastics or the subsequent fire extinguishing device is developed by a diverse range of organic compounds. The wide range of compounds was chosen phosgene, formaldehyde, acetaldehyde, PAHs and extremely toxic. When burning the noxious substances into the air first and then wet or dry slope to reach the other components of the environment. These combustion products have diverse adverse effects on both humans and the environment. In some cases, these substances have fatal consequences for all components of the environment.
Landfill Sites and Landfill Gas Risks
Klímová, Zdeňka ; Vávrová, Milada (referee) ; Valášek, Rudolf (advisor)
This work is focused on landfills and landfill gas that is created by decomposition of organic substances. Municipal waste, its origin, properties, practical use and risks related to landfill gas are discussed. At the end of the theoretical section the limits of explosiveness are specified. The practical section deals with the most important properties of methane and carbon dioxide. A photograph of a landfill site, located in Brno – Černovice, is included in the final section.
Influence of technological processes on the content of priority contaminants in wastewater treatment plants
Mikulíková, Iva ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
Water is one of the most abundant substances on Earth and it is an essential part of our lives. Its pollution has an impact on the whole ecosystem. Polybrominated diphenyl ethersare synthetic persistent organic pollutants used as flame retardants in various commercial and household products. This thesis is focused on assesing the degree of elimination of PBDEs in wastewater treatment plants with different technological processes of purification. The samples were collected in the three wastewater treatment plants in the south-moravian region, that means WTP Brno – Modřice, WTP Mikulov and WTP in VFU Brno.
Bisphenol A in water ecosystem
Nohelová, Gabriela ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
This diploma thesis deals with Bisphenol A, especially with its impact on the aquatic ecosystem. Information about its properties, production and current use are summarized here. Its harmful impact on the environment, especially on the aquatic ecosystem and the human body is characterized. Also the methods of its degradation within the aquatic environment have been described. A summary of the options of a determination of Bisphenol A in water samples is incorporated and the method of gas chromatography with mass spectrometry (GC/TOF MS) and comprehensive two-dimensional gas chromatography with mass spectrometry (GCxGC/TOF-MS) is compared in the experimental part. Analytical determination precedes the isolation of the analyte from the water samples by solid phase extraction (SPE) using SupelcleanTM ENVITM - 18 and derivatization using the silylation reagent, N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). The result of this work is the analysis of a series of real samples from wastewater treatment plants Brno Modřice and Luhačovice by a two-dimensional gas chromatography with mass spectrometry (GCxGC/TOF-MS).
Ecotoxicology of nanoparticles
Vavrčíková, Veronika ; Vávrová, Milada (referee) ; Zlámalová Gargošová, Helena (advisor)
This thesis deals with the characterization of nanoparticles, their behaviour and ecotoxicity in the environment. A brief description of nanotechnology is given together with the overview of the most commonly used nanoparticles in industry, medicine and other applications. Their sources and their fate in the environment are further described. Possibilities of ecotoxicological testing of the most commonly used nanoparticles with the most frequent occurrence in the environment are evaluated. At the same time sufficiency of currently used ecotoxicological test is assessed and necessity of their modification owing to the specific characteristics of nanoparticles is discussed.

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