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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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Food products with probiotics
Zemanová, Tereza ; Valicová, Markéta (referee) ; Trachtová, Štěpánka (advisor)
Fermented dairy products containing probiotic microorganisms which are distinguished by favorable effects on the intestinal microflora, are in present time consumed in large quantities. Products range in which microorganisms are contained in recent years expanded greatly. On the market are currently available not only milk, but also meat or vegetable products of this type. The aim of work was to get acquainted with probiotic microorganisms, a description of their use in food industry, and whether they have for us “Homo sapiens sapiens,, favorable or unfavorable effects. In the practical part of work was showed the presence of probiotic bacteria in fermented dairy product using the polymerase chain reaction methods.
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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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Probiotic lactic acid bacteria in food products
Sásková, Denisa ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
In food industry molecular genetic methods based on DNA analysis are used for identification of probiotic microorganisms. An example of these methods is the polymerase chain reaction, in which specific fragments of DNA are amplified using short oligonucleotide primers. The teoretical part of this bachelor thesis follows probiotic bacteria, their features, beneficial health effects and use in food and clinical applications. The experimental part of the thesis focuses on an analysis of two probiotic dietary supplements. DNA was isolated from these products by method of phenol extraction. The use of PCR confirmed the presence of DNA of probiotic bacteria of genera Lactobacillus and Bifidobacterium.
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Identification of probiotic species of genus Lactobacillus
Vystavělová, Růžena ; Trachtová, Štěpánka (referee) ; Rittich, Bohuslav (advisor)
Germs of the Lactobacillus genus form part of the micro flora, the composition of which exercises the influence on the state of health of its host. In view of the fact that at some types of Lactobacillus there were proved clinical effects (e. g. strengthening of the immune system, prevention of diarrheic illnesses and so on), the Lactobacilli have been often used for making fermented dairy products and they form part of food additives because of their probiotic effect. Germs of the Lactobacillus genus and germs of different types of Lactobacillus can be identified by means of PCR based on amplifying specific DNA fragments. The complete bacillary DNA Lactobacillus rhamnosus was separated by the phenolic extraction method. The presence of germs of the Lactobacillus genus was proved by the generic-specific PCR method; the presence of Lactobacillus rhamnosus germs was proved by the species-specific PCR method.
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Molecular typisation of lactic acid bacteria
Jelínek, Zdeněk ; Ing. Špano Miroslav,PhD. (referee) ; Rittich, Bohuslav (advisor)
Lactic acid bacteria play important role both in food industry and health care. They are part of many fermented dairy products and gastrointestinal microflora. There is a whole variety of methods for bacteria identification, but we will focus on Rep-PCR and RAPD only. The aim of this work will be to discuss the impact of different correlation coefficients and cluster analysis algorithms on the results of taxonomic analysis.
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Lactic acid bacteria and their utilization
Jiříková, Ivana ; Vránová, Dana (referee) ; Babák, Libor (advisor)
This bachelor thesis is aimed at the study of lactic acid bacteria. Within the frame of this thesis I have performed a literature research into findings about these bacteria. The first section is focused on the general bacteria identification and division into separate genus groups. It also describes the cytology, metabolism and industrial use of milk fermentation bacteria.
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Probiotic foods
Páterová, Alena ; Navrátilová, Jana (referee) ; Vítová, Eva (advisor)
This bachelor thesis summarizes the knowledge about problematic of probiotics and their positive effects on human health. Probiotics are live microorganisms, which, at application in appropriate quantity as component of food, have health benefit in humans and animals. Probiotics are already an important component of treatment in gastroenterology, in hepatology, at treatment of urogenital system, at prevention and therapy of cancer and mycoses. The best known probiotics are lactic acid bacteria, of which most often used are Lactobacillus and Bifidobacterium genera. Lactic acid bacteria because of their unique metabolic characteristics are involved in many fermentation processes of milk, meat and vegetables. We can say, that advances in probiotic bacteria research are beneficial for both the consumers and the producers.
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Identification of lactic acid bacteria in food products using amplification methods
Jurečková, Nela ; Trachtová, Štěpánka (referee) ; Španová, Alena (advisor)
The aim of the study was isolation of genomic DNA from 7 milk products (yogurts/ yogurt milk) in quality for use it in PCR. Magnetic microparticles (P(HEMA-co¬-GMA)) were used for the DNA isolation. DNA was reversibly adsorbed to the microspheres in the presence of 8% poly(ethylene glycol) PEG 6000 and 5 M sodium chloride. The adsorbed DNA was released from the microspheres in a low ionic strength TE buffer and use as DNA matrix in genus specific PCR Lactobacillus. The presence of DNA of genus Lactobacillus was detected in all analysed products.
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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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