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Influence of production environment on the occurrence of contaminating Penicillium in smear ripened cheese
Veselá, Vendula ; Brázda, Václav (referee) ; Vítová, Eva (advisor)
The topic of this thesis is the monitoring of the environment in a cheese production plant specializing in cheese ripened under a smear rind. The aim is to evaluate the occurrence of Penicillium mold as the main contaminant microorganism, depending on the sampling location and production time. Air samples were collected throughout the production process using the sedimentation method at 21 designated locations. The total number of microorganisms, selected groups of microorganisms, and the target microorganism (Penicillium mold) were monitored in the collected samples using cultivation (according to ČSN standards), microscopic, and molecular diagnostic techniques. The aim was to evaluate the occurrence of Penicillium citrinum, chrysogenum and commune species in dependence on the sampling location and production time. As part of the production screening, the broader microflora was first evaluated, followed by monitoring for contaminating molds. Using macroscopic and microscopic methods, 36 morphologically distinct colonies were selected. Microscopic analysis confirmed the presence of bacteria, yeasts and molds of the genera Penicillium, Cladosporium and Aspergillus. In order to identify the microorganisms present, an analysis using the polymerase chain reaction (PCR) method was performed, preceded by DNA isolation using the NucleoSpin Microbial DNA kit and phenol extraction. Based on real-time PCR results, the occurrence of contaminating Penicillium and Cladosporium molds was detected even in the early stages of production. Molds from these genera are found throughout the entire facility except for the single room that serves as a curd cooler before forming. Aspergillus mold, in the form of yellow mold with white mycelium on the edge of the colony, was detected only once in the drying room where cheese ripening occurs, and confirmed by microscopic observation. The genus Cladosporium was found in five morphologically distinct forms in the production environment. In addition, DNA was isolated from 11 morphologically distinct bacteria. Real-time PCR identified this DNA as belonging to coryneforms, with four of them belonging to the genus Brevibacterium. The genus Penicillium was represented by 13 morphologically distinct colonies, real-time PCR confirmed the presence of Penicillium commune and Penicillium chrysogenum. In addition to the mentioned molds, 11 morphologically distinct bacteria were detected, from which DNA was isolated. Real-time PCR identified this DNA as belonging to coryneforms, with 4 of them belonging to the genus Brevibacterium. The results of this work completely map the contamination of the production environment of the plant, and based on these results, methods for environmental sanitation were proposed to ensure the decontamination of the production process.
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Factors influencing the quality of red wine
Zechmeisterová, Lucie ; Vránová, Dana (referee) ; Omelková, Jiřina (advisor)
In my thesis, I focused on monitoring of microorganisms in the sample of red grape juice and on the interactions between yeasts, bacteria and filamentous fungi. Three different media were applied for the cultivation of microorganisms; firstly for monitoring of total volume of microorganisms, secondly for yeasts and third time for lactic acid bacteria. The indirect method was used for the determination of the amount of viable cells. This method consists in enumerating of visible macroscopic colonies grown up on agar plates. When the cells grew up, the forms of colonies were analyzed visually and the morphology of microorganisms was detected microscopically. The operating time of enzymes in grape juice in the production of red wine was monitored after application of commercial enzymatic preparation. The enzym action in grape juice was observed on the basis of the process of degradation of high – molecular substrate by enzymes through the use of Ubbelohd´s viscometer. The research findings provided a lot of knowledge about the occurance of microflora in the process of production of red wine. The commercial preparations added to grape juice played a significant role.
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The Health Conditions of Ornamental Plants of the Family Begoniaceae in Greenhouse Systems
DEMELOVÁ, Šárka
The main aim of this study was to identify patogenes, which cause dying of begonia tubers while dormancy. Experiments consisted of two main parts: detection fungal pathogens during the vegetation and laboratory tests of hybernating tubers. Begonia plants were controled regularly once per week during the vegetation for health and number of healthy, disease and dying plants. For laboratory tests were used tubers before dormancy and healthy and disease ones for testing during vegetation season. The selection of tubers for testing was based on results from last season, when the tubers were compared in mortality. Depending on this factor were selected mutatins: the most sensitive (begonia tuberhybrida white), ordinary (Begonia pendula yellow-orange) and the most resistent (Begonia tuberhibrida cinnabar, red). Plants were observed at all phases of vegetation.
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Sledování úrovně mikrobiální kontaminace vybraných druhů čajů
Polášek, Viktor
This Diploma thesis describes the history of tea, its charakterisic, technologic processing, chemical structure and effect on human organism, as well as requirements of legislation. This is followed by characterization of microbes which contaminate teas, products of their metabolism which have negative effects on human health (especially mykotoxins) and struglge against these microbes. Experimental part is orientated on assignment of significant groups of microbes in samples of tea in draw leaves and prepered tea.
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Factors influencing the quality of red wine
Zechmeisterová, Lucie ; Vránová, Dana (referee) ; Omelková, Jiřina (advisor)
In my thesis, I focused on monitoring of microorganisms in the sample of red grape juice and on the interactions between yeasts, bacteria and filamentous fungi. Three different media were applied for the cultivation of microorganisms; firstly for monitoring of total volume of microorganisms, secondly for yeasts and third time for lactic acid bacteria. The indirect method was used for the determination of the amount of viable cells. This method consists in enumerating of visible macroscopic colonies grown up on agar plates. When the cells grew up, the forms of colonies were analyzed visually and the morphology of microorganisms was detected microscopically. The operating time of enzymes in grape juice in the production of red wine was monitored after application of commercial enzymatic preparation. The enzym action in grape juice was observed on the basis of the process of degradation of high – molecular substrate by enzymes through the use of Ubbelohd´s viscometer. The research findings provided a lot of knowledge about the occurance of microflora in the process of production of red wine. The commercial preparations added to grape juice played a significant role.
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