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Analysis of mycotoxins from biological matrices using biomembranes and capillary electrophoresis
Kubová, Natália ; Šesták,, Jozef (referee) ; Duša,, Filip (advisor)
This thesis summarizes knowledge about mycotoxins, with focus to ochratoxin A. It also summarizes its tolerable levels of food intake, detoxification and analytical methods for mycotoxins. The work also includes a chapter describing liposomes that were used for the analysis of ochratoxin A by liposomal electrokinetic capillary electrophoresis (LECK). The practical part includes the analysis of ochratoxin A from Aspergillus ochraceus Wilhelm and Aspergillus melleus Yukawa fungi cultivated on a rye and optimization of the method for analysis of ochratoxin A based on liposomes of different compositions. By capillary zone electrophoresis, ochratoxin A is not sufficiently separated and detected in the extracted mixture; conversely, when liposome solutions are used, different migration behavior can be achieved while stabilizing ochratoxin A in solution due to amphiphilic interactions between mycotoxins and liposomes. Therefore, the LEKC method was used for this work. The most suitable liposome composition has been shown to be molar ratios of 25% cholesterol (membrane stabilization) / 50% 2-oleoyl-1-palmitoyl-sn-glycerol 3-phosphocholine (main zwitterionic lipid) / (25% 1,2-diacyl-sn-glycerol)-3-phospho-L-serine (introduction of negative charge).
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Analysis of beta-glucans in some fungi
Phan, Huong Tra ; Veselá, Mária (referee) ; Márová, Ivana (advisor)
The main goal of this thesis was to analyse the amount of beta glucans in selected mushroom species. The overall characterization of the composition and content of bioactive compounds in mushrooms was studied too. The theoretical part was focused on description of Fungi, especially the Basidiomycota phyla. The overview of fungal morphology and chemical composition was elaborated. Further, theoretical basis of analytical methods used was introduced. In the experimental part, extracts from selected species of mushrooms (shiitake, oyster mushroom, white champignon, brown champignon and jew’s ear) were prepared. Overall group parameters such as polyphenols, flavonoids, antioxidant activity were determined by spectrophotometry. The amount of beta-glucans in the fungi was measured after enzyme hydrolysis using commercial kit. The content and composition of fatty acids was measured by gas spectrometry. Using emission spectrometry (ICP/OES) the presence of heavy metals was analysed in fungal extracts. Cytotoxicity was tested by MTT test on human cell lines. In the last part the antimicrobial activity against Gram-positive bacterium Micrococcus luteus, Gram-negative Serratia marcescens and yeast Candida labrata was tested. In the thesis, a complex characterization of composition and biological effect of some mushrooms was given.
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Influence of storage conditions on content of biologically active substances in apple fruits.
Ferdová, Jitka ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This study deals with antioxidants in diet and their effects on human organism. Further, it summarizes the agents affect the quality of apples in the course of long-term storage and it outlines the possibility of defence against them. In the experimental part methods of determination of antioxidant enzymes superoxid dismutase (SOD), catalase and polyphenol oxidace (PPO) in apples were introduced. The enzymes were measured in apples tissues in liquid nitrogen after 158 days in normal or modified atmosphere. In Apple the quantitative and qualitative analysis of proteins was realized. Further, some low molecular antioxidants (total phenolics, total flavonoids and vitamin C) as well as total antioxidant status were measured in frozen raw juice. This values were compared with values from apples analyzed immediately after the harvesting. Artificial inoculation with fungi was made in the last part and the fruitfulness was observed.
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Microorganisms with lipoplytic activity and their applications
Pavlačková, Jana ; Omelka, Ladislav (referee) ; Omelková, Jiřina (advisor)
Lipases are hydrolytic enzymes that are produced by many types of microorganisms. This thesis describes not only the microorganisms which produce lipases but also different possibilities for the industrial utilization of lipases. Lipases are widely used in reactions where the combination of a lipophilic substrate with a hydrophilic one is necessary – in the synthesis of ascorbic acid fatty esters, sugar esters, lipoaminoacids and in the lipophilization of phenolic derivatives. Lipases are also important in relation to environmental protection. For example, they are used for the purification of waste water. In this thesis, five different preparations containing microorganisms with lipolytic activity were tested for lipolytic activity. There are many ways of determining lipolytic activity. The spectrophotometric determination of lipolytic activity that uses the ability of lipases to divide p-nitrophenyllaurate to p-nitrophenol may serve as an example. After this p-nitophenol is detected spectrophotometricaly.
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Development of mycorrhizal communities in primary succession
Mádle, Jan ; Kohout, Petr (advisor) ; Ponert, Jan (referee)
Primary succession is the process of ecosystem development that takes place in sites that were not suitable for colonization by plants and organisms dependent on them. These sites arise either naturally, for example after a volcanic eruption or glacial retreat, or anthropogenically, for example by strip mining. During primary succession, plants colonise the bare substrate and gradually modify its abiotic and biotic conditions. During primary succession, interactions between plants and the soil microbiome, especially with fungi and bacteria, occur. Plants and soil microorganisms influence each other's growth and development through various interactions. Plants, or rather their roots, form a specific niche for a wide range of soil microbial communities. Through their roots, plants provide a wide range of substances, organic acids, sugars, amino acids and other often carbon-rich compounds that can serve as a substrate for microorganisms. Plants are able to do this by producing litter, root exudates, and translocation of sugars for symbiotic fungi and bacteria. Soil microorganisms contri- bute to the release of nutrients and the decomposition of organic materials that would otherwise be unavailable to plants. Many soil microorganisms can form a symbiotic relationship with the plant; this relationship may be...
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Influence of plasma activated water on fungal diseases
Moskvina, Anastasia ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
This bachelor thesis focuses on influence of plasma treated water on fungal diseases. The theoretical part is dedicated to plasma-liquid interactions, properties and application of plasma activated water and its influence on different microorganisms. Plasma activated water contains reactive oxygen species which cause inactivation of living cells, making it a potential sterilizer. The experimental part of this work compares the effectiveness of three plasma treated water preparation techniques. Dielectric barrier discharge system was used to activate water above its surface. For the under the surface activation, a two-electrode system of both alternating and direct current was used. Plasma treated water was then used to prepare a suspended mixture with Aspergillus niger spores. The latter was then cultivated on agar plates for 72 hours. The overall effect was evaluated in amounts of colony forming units. The experimentally obtained data was processed and discussed in the results and discussion section of the thesis. It was found that the underwater surface activation had more significant effect on mold deactivation, which corresponds with the information contained in the theoretical part. Although the effect of dielectric barrier discharge was not as promising, all three methods used led to a decrease of colony forming units in comparison to the non-treated control sample.
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Molecular and Genomic Methods for Analyzing Hybridization in Aspergillus and other Fungi
Jirkovský, Pavel ; Sklenář, František (advisor) ; Kolařík, Miroslav (referee)
Interpecies hybridization is being studied since the first half of 20. century, when it was described based on phenotypical traits on plant model. Study of this process was historically centred around botanical studies, while its importance in mycology is just being uncovered in recent years. Introgression is a phenomenon that can occur when hybrid backcrosses with one of the parental species. Based on recent studies it is apparent that hybridization played its role in evolution of MAT locus genes of Neurospora, transfer of adaptive traits with Ophiostoma species (invasive pathogen of elm trees). Within Aspergillus family hybridization was described both on intraspecific and interspecific level. More detailed study of this process and improving of used methods could potentially help in clinical application by uncovering adaptive genes responsible for resistance towards antimycotics, higher virulence and other traits.
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An analysis of fungal exudate and carbon use efficiency
NÜBL, Laura
The exometabolome of various fungal functional guilds was investigated as part of the below-ground carbon flux. This thesis addresses the incorporation and exudation of carbon by individual, axenic fungal cultures, with a focus on developing a protocol for characterisation and identification of those compounds.
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The evaluation of 137Cs content in mushrooms and forest berries in the South Bohemia region
HÁLOVÁ, Jana
The collection and consumption of forest fungi and blueberries are among the most popular seasonal activities in Czech Republic. Due to the Chernobyl accident, however, these raw materials are believed to have contained increased amounts of radionuclides. The aim of the work is to evaluate the content of 137Cs in blueberries and fungi collected from South Bohemian region in the period of 1992 - 2020. Data of 137Cs mass activity obtained from the State Office for Nuclear Safety's MonRas database were re-examined for validation using samples of fungi (n = 318) and blueberries (n = 142). The results ranged widely as follows: (a) boletes fungus, from 0.18 to 6430 Bq / kg; (b) leafy fungus, from 0.28 to 4040 Bq / kg; and (c) blueberries, from 0.24 to 2046 Bq / kg. Between boletes fungus and leafy fungus, the former was seen to have a higher ability to accumulate the radionuclide 137Cs. The calculated effective dose caused by the consumption of fungi and blueberries was assessed as negligible, amounting only to less than 1% of the general limit for the population. Despite these favorable results, detailed monitoring of raw materials from nature needs to be continued and the safety of the food chain ensured.
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Houby vřesovišť CHKO Brdy
SYNKOVÁ, Hedvika
The aim of this thesis was to assess the impact of controlled fire on fungal community in heathlands in CHKO Brdy and describe their changes during succession. Fungal fruitbodies were monitored during years 2018 and 2019 at twenty-five monitoring plots at Jordán, Tok and Brda. The relationship between fungal species richness and the time since the last fire and soil humidity was determined. The effect of the time since the last fire, soil humidity and vegetation on fungal species composition was analysed using multivariate ordination methods. The quality of studied habitat was evaluated based on the presence of red-listed and indicator fungal species.
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