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Identification of lactic acid bacteria in probiotic products (tablets) using amplification methods
Balogová, Petra ; Trachtová, Štěpánka (referee) ; Španová, Alena (advisor)
Lactobacillus have been playing a crucial role in the fermentation processes for millenia. Their probiotic effects have been studied deeply and nowadays they are used in the production of fermented products and food adjunkt including probiotic preparations. This thesis was focused on bakteria of genus Lactobacillus in probiotic preparations (tablets). Polymerase chain reaction method (PCR) based on amplification of DNA was used to identify lactobacillus in seven probiotic preparations. As DNA matrices whole DNA recovered from tablets with the help of magnetic microparticles (P(HEMA-co¬-GMA) coated by carboxylic groups was used into a PCR mixture. Genus specific PCR products (250 bp) were detected with the help of gel electrophoresis on agaróse. DNA of genus Lactobacillus was proved in all but one product. In this product only probiotic bacteria were declared presence without family identification was proved. It contained different bakteria then bakteria of Genus Lactobacillus probably.
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Methods for detection of antimicrobial properties of lactic acid bacteria
Vránová, Petra ; Němcová, Andrea (referee) ; Trachtová, Štěpánka (advisor)
Lactic acid bacteria are classified as probiotics producing substances that act against microorganisms. These antimicrobial substances include organic acids, carbon dioxide, hydrogen peroxide and bacteriocins. Currently, the focus is on bacteriocins, which are used in the food and pharmaceutical industries. The aim of this thesis is creating an overview of antimicrobial properties of lactic acid bacteria, methods of their determination and their applications in the food industry. The experimental part deals with identification of lactic acid bacteria present in selected samples of bacterial DNA. In addition, we tested for bacteriocin Gassericin K7A-producing gene. Molecular diagnostic methods such as real-time polymerase chain reaction (qPCR) and conventional polymerase chain reaction were used to distinguish bacterial DNA as well as the bacteriocin.
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Production of biogenic amines in double moulded cheese
Šuláková, Miroslava ; Standara, Stanislav (referee) ; Veselá, Mária (advisor)
For production of double moulded chesses are used lactic acid bacteria, which can be present in a form of non-starter lactic acid bacteria or as starter or adjunct culture. Genera Lactobacillus spp. and Enterococcus spp. are prevalent microorganisms present in these cultures. Of course, these microorganisms are for us interesting because of their possibility of coagulation, proteolytic possibility, probiotic function and antibiotic resistance, but especially because of their decarboxylation abilities. Bacteria contain decarboxylation enzymes, which are able to decarboxylized free amino acid, which rising at proteolysis during process of manufacturing and cheese ripening. Biogenic amines are the result of proteolytic activity. Biogenic amines occur practically in all foodstuffs as a common product of metabolic processes. BA are mainly presented in fermented food (cheeses), where rice just microbial action. Typical representatives of biogenic amines, which occurs in double moulded cheeses (Sedlčanský Vltavín, Bresse bleu) and in blue cheeses (Bleu des Causses, Bleu d'Auvergne) are cadaverine, putrescine, tyramine a 2 fenylethylamine and in much smaller amount histamine, spermidine and spermine too. On assessment concentration of BA is used high pressure liquid chromatography with reverse phase (RP HPLC) with utilizing simple direct derivatization with dansyl chloride and detection by UV VIS detector.
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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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Microbial characterization of yoghurts and probiotic foods.
Kocourková, Hana ; Burdychová, Radka (referee) ; Španová, Alena (advisor)
Zvýšená konzumace fermentovaných mléčných výrobků v posledních letech vede k zavádění nových výrobků na trh. Funkční a probiotické produkty jsou v dnešní době také hojně rozšířeny. Cílem diplomové práce bylo posoudit mikrobiální kvalitu komerčních jogurtů a nefarmakologických probiotických výrobků. Bylo zkoumáno 24 vzorků jogurtů a 8 vzorků probiotických mléčných výrobků. Pozornornost byla zaměřena zvláště na kvantifikaci mikroorganismů v jednotlivých výrobcích a na sledování viability buněk. Většina mléčných produktů obsahovala počty odpovídající minimální požadované hodnotě 1x107cfu/ml. Nicméně byly objeveny produkty, které neobsahovaly živé bakterie nebo obsahovaly jen jejich menší množství. To platí zejména pro běžné jogurty. Probiotické mléčné výrobky v zásadě obsahovaly větší množství bakterií než jogurty, protože je u nich navíc požadováno 1x106cfu/ml minimálního množství specifických bakterií jiných než jogurtových startovacích kultur. Isoláty z fermentovaných mléčných výrobků byly identifikovány jako Streptococcus thermophilus and Lactobacillus spp. Isoláty byly poté rozlišeny na jednotlivé kmeny pomocí RAPD použitím tří různých primerů. Byla zjištěna velká různorodost mezi kmeny rodu Lactobacillus spp. používaných různými podniky.
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Kinetic of lactic acid formation in kefir
Fajtl, Zbyněk ; Vítová, Eva (referee) ; Veselá, Mária (advisor)
This bachelor thesis deals with the kinetic production of lactic acid and consumption of lactose in the kefir fermentation from one type of milk under the same conditions. The theoretical part contains information on kefir and kefir grains, lactose intolerance, antimicrobial properties and high-performance liquid chromatography. The experimental part describes the methods and procedures used in the manufacture of kefir itself, the determination of lactic acid and lactose. Kefir samples were tested at precise time intervals for lactose, lactic acid and lactobacilli. The data was graphically evaluated and commented. The results of this work may be beneficial for consumers with lactose maldigestion and for consumers searching for qualite source of lactobacilli for enhancing their gut microflora.
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Factors affecting stability and consumer acceptance of sauerkraut water
Vašků, Barbora ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on the optimization of pasteurization of the cabbage juice in order to extend its shelf life. The theoretical part is focused on the description of the sauerkraut production technology and characterization of the main components of fermented cabbage and its juice, it also deals with pasteurization options and presence of probiotic strains. In the experimental part, the composition of the brine was analyzed from a chemical point of view (bioactive substances, sugars, carbohydrates), from a microbiological point of view (presence of probiotics, pathogenic organisms) and the effect of selected pasteurization processes on these components. Pasteurization at 90 °C for 0.5 minutes was determined as the most suitable treatment, during which potential pathogens are being eliminated, while most of the original bioactive components are preserved. After suggesting the effective pasteurization treatment, suitable species of genus Lactobacillus was selected to enrich the cabbage juice product because of decreasing of probiotics viability during pasteurization treatment. The strain Lactobacillus plantarum was determined as the most suitable probiotic species for cabbage juice enrichment, due its ability to survive in 2 weeks storage at 8 °C in cabbage juice. Chemical composition after 2 weeks of incubation with mentioned organism has changed. Quantity of lactic and acetic acid increased, while no changes in content of vitamin C were observed. Finally, sensory analysis was performed to evaluate suggested mixed fruit-vegetable drink. According to results of sensory analysis, the drink composed of cabbage juice and apple-beetroot juice in the ratio of 2:1 was found as the most acceptable.
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The content of lactic acid bacteria in several types of probiotic foods
Páterová, Alena ; Vránová, Dana (referee) ; Vítová, Eva (advisor)
Probiotics are defined as live microorganisms that have, if ingested, a positive impact on human and animals health. The best known probiotics are the lactic acid bacteria, among them most commonly used are lactobacilli and bifidobacteria. For therapy the minimum daily consumption of at least 100 g of milk product with a minimum 1000000 of probiotic bacteria in 1 g or 1 ml is considered. In this work, several products that have declared on the label probiotic cultures have been selected. All products were analyzed for the number of lactic acid bacteria. Two media - MRS agar and skim milk agar Modified were used for cultivation. Cultivation proceeded at 37 °C for 48 hours under aerobic and anaerobic conditions. Amount of live bacteria, which must be present in the product, indicates Ministry of Agriculture No. 77/2003 Coll.. Quantitative representation of lactic acid bacteria in all selected products comply with the requirements of legislation.
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The monitoring of the lactic acid bacteria in the Moravian wines
Valicová, Markéta ; Španová, Alena (referee) ; Omelková, Jiřina (advisor)
The aim of this Master Degree Thesis was to monitor the total number of lactic acid bacteria occurring in grape must during wine production. The study was performed on the red wine grape variety Cabernet Moravia from organic vineyard and on the white wine grape variety Sauvignon from both organic and integrated vineyards. The isolation of pure cultures of lactic acid bacteria from mixed cultures and subsequently their identification by genus and species-specific PCR was also subject of the thesis. The experimental results show that the number of viable cells of lactic acid bacteria is influenced not only by the wine grape variety, whether it is a variety of red or white wine grape, but also by the way of wine growing. The method of wine growing also had an impact on the species representation of lactic acid bacteria in each variety.
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Biological synthesis of silver nanoparticles
Kubínová, Martina ; Španová, Alena (referee) ; Rittich, Bohuslav (advisor)
Silver nanoparticles and its potencial use and influence on the environment is still object of research. Methodics of synthesis of silver nanoparticles is already well investigated and study deals with more economical ways of syntesis by metireals, which are environmentally friendly and nontoxic. Biochemical production of nanoparticles has both advantages. This study focused on the production of nanoparticles by lactic acid bacteria and antibacterial activity. Experimental part of the study focused on amplification DNA isolated from Lactobacillus gasseri K7, which has efficiency to form silver nanoparticles. DNA was isolated in PCR, it was confirmed using primers specific for domena Bacteria and species Lactobacillus gasseri.
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