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Identification of bacteria of Lactobacillus acidophilus species in probiotic products
Sznapková, Veronika ; Trachtová, Štěpánka (referee) ; Španová, Alena (advisor)
Probiotic lactic acid bacteria (LAB) are an important part of fermented dairy products, pharmaceuticals and food supplements. At present, rapid and accurate identification of bacteria is carried out using molecular biological methods based on DNA amplification. The aim of the thesis was to identify by non-cultivation bacteria of genus Lactobacillus and bacteria of species Lactobacillus acidophilus in complex matrices at total of seven different food supplements. Total DNA was isolated from crude cell lysates using magnetic carrier P(HEMA-co-GMA). Amplificability of DNA was verified by PCR using primers specific for the domain Bacteria. In next step isolated DNA was amplified using primers specific for the genus Lactobacillus and species Lactobacillus acidophilus to demonstrate the presence of this bacterial genus and species declared by the producers. The results of bacteria identification obtained by PCR were compared with declared specification given by the producers.
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The use of magnetic microparticles for DNA isolation
Jelínek, Zdeněk ; Horák, Daniel (referee) ; Rittich, Bohuslav (advisor)
The effectiveness of magnetic microparticles in isolation of DNA from Lactobacillus rhamnosus CCM 1825T and DNA from chicken erythrocytes were studied in diploma thesis. Magnetic HEMA based microparticles coated by carboxylic groups and hyperbranched styrene-divinylbenzene particles (IMC AS ČR, Prague, Czech Republic) were used for DNA isolation. Magnetic microparticles Dynabeads® DNA DIRECT™ Universal (Dynal, Norway) based on polystyrene and MPG® Uncoated (PureBiotech, USA) based on magnetic glass were used as a control. The dependence of amount of eluted DNA on concentration of DNA in the base solution and the dependence of amount of eluted DNA on concentration of magnetic microparticles were studied. The affinity of magnetic microparticles to RNA for various concentrations of RNA solution was studied, too. The ability of tested particles to isolate DNA from real samples was validated using milk product Actimel. The quality of isolated DNA of Lactobacillus genus was proved using genus specific PCR.
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Probiotics and prebiotics in food and other products
Langová, Denisa ; Havlíková, Šárka (referee) ; Trachtová, Štěpánka (advisor)
Theoretical part of this thesis focuses on present state and research of probiotics and prebiotics, their use for microflora modulation of host and their beneficial effects on the health of individuals. Furthermore thesis deals with efficiency of probiotics strains, which depends on the food matrix and other various factors. The experimental part focuses on the identification of chosen bacterial strain, which is contained in probiotics product. It is realized due the isolation of bacterial DNA by phenol extraction and by use of magnetic particles and subsequent analysis of obtained DNA by polymerase chain reaction (PCR).
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Analysis of the composition of selected probiotic products by PCR-HRM
Tomanová, Barbora ; Španová, Alena (referee) ; Trachtová, Štěpánka (advisor)
This work was focused on the detection of probiotic bacteria in four different probiotic products (probiotic cream, probiotic tampons, oral probiotics and soy beverages with probiotics). The viability of the bacteria contained in the products was verified. Complex matrices of the products were used to isolate DNA in a quality suitable for the PCR method, followed by identification of the declared bacterial genus and species. Amplification was achieved with conventional PCR and real-time PCR, genus- and species-specific primers were used. Bacteria, of the genus Lactobacillus and Bacillus and bacterial species Lactobacillus pentosus, Lactobacillus rhamnosus, Lactobacillus fermentum and Lactobacillus gasseri, were proven to be within the products. Subsequently, the DNA from mixed bacterial species in the probiotic tampon were distinguished using PCR-HRM. Five sets of primers were used to test this. Two sets of primers (primers P1V1, P2V1 and V1F-HRM, V1R-HRM) were evaluated as the most suitable for resolution.
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Magteic particles and their applications in biotechnology
Knápková, Monika ; Konečná, Jana (referee) ; Trachtová, Štěpánka (advisor)
The thesis is focused on the magnetic particles which are used in several biotechnological applications. The theoretical part deals with the specific properties of these nanoparticles and materials of which the nanoparticles can be made. There are also mentioned some of the biotechnological applications of magnetic particles. During the experimental part, selected types of magnetic particles were used to isolate nucleic acid. The quality of the isolated DNA with respect to purity was evaluated using the polymerase chain reaction and its modifications. High resolution analysis (HRM analysis) was also used to verify the quality of the isolated DNA and to resolution Lactobacillus casei and Lactobacillus rhamnosus. DNA isolation using magnetic carriers was successful. Commercially available MPG microcarriers and magnetic microparticles Fkol 77ox were the most suitable. In terms of purity magnetic nanoparticles F79/L3-PLL were the most suitable for the DNA isolation. The resolution of bacterial strains of Lactobacillus casei and Lactobacillus rhamnosus was not successful.
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Magnetic carriers and their practical use
Chlopková, Barbora ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
The theoretical part summarizes the current knowledge for practical use of magnetic carriers in molecular diagnostics. It includes both already used methods and methods with potential for the future. In the experimental part was tested by use of magnetic media for isolation of DNA from a dairy product and a bacterial culture. It was confirmed that the magnetic carrier DNA was isolated in quantity and quality suitable for carrying out polymerase chain reaction.
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Recombinant probiotics
Surá, Tereza ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
Theoretical part of this thesis focuses on present state and research of recombinant probiotics and their use in food industry and health care. It also concentrates on their beneficial effects on the health of individuals. The experimental part focuses on the identification of specific bacterial strain in a probiotics food supplements. The DNA was isolated from these products by use of magnetic microparticles and obtained DNA was subsequently analysed through polymerase chain reaction.
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Probiotics and their use in food industry
Diado, Aleksandra ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
Probiotic bacteria are defined as live microorganisms, which when consumed in the determining quantities, have healthy and beneficial effects. Most of probiotics belongs to the genera Lactobacillus and Bifidobacterium. These and other genera of microorganisms are successfully used in industry, including food industry at present. Probiotics are used primarily in dairy products and food additives in food idustry. Probiotic bacteria, like other organisms, can be to identifie by PCR method that allows amplifying specific regions of DNA. Polymerase chain reaction was performed after DNA isolation from bacterial cultures of three strains using phenol extraction method. PCR specific for the domain Bacteria and genus-specific PCR were used for the confirmation of the presence of bacteria of the genus Lactobacillus.
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Applications of real-time PCR for characterization particles suitable for DNA isolation
Ondrejková, Martina ; Šálek, Petr (referee) ; Trachtová, Štěpánka (advisor)
The theoretical part of the diploma thesis was focused on core-shell type magnetic carriers, used mainly in medical, molecular-biological and biochemical applications. Encapsulation of the core is essential for these applications due to the decrease od non-specific protein adsorbtion, increase of biocompatibility and the possible functionalization of magnetic carriers. In the experimental part, the DNA (E. coli) was amplified by real-time PCR in the presence of poly(hydroxymethacrylate-co-glycidylmethacrylate) (P(HEMA-co-GMA)) magnetic carriers with/without carboxyl groups. The inhibitory effect of different concentrations of magnetic carriers in the PCR mixture was evaluated from the calibration curve parameter values obtained by regression analysis. The presence of a specific PCR product was verified by agarose gel electrophoresis. Most of magnetic carriers without carboxyl groups extinguished the fluorescence in the concentration range of 2,0 – 4,0 g.l-1 in the PCR mixture, without inhibition of DNA amplification - the carriers were biocompatible. Magnetic carriers with carboxyl groups extinguished the fluorescence in the lower concentration range (0,4 – 4,0 g.l-1 in the PCR mixture). Their inhibition of amplification was in the concentration range of 2,0 – 4,0 g.l-1 in the PCR mixture, from the concentration 0,8 g.l-1 in the PCR mixture, the inhibition did not occur and the carriers were biocompatible. The results do not depend on the characteristic properties of the magnetic carriers but on the presence of the carboxyl groups on the surface of the carrier and the degree of coverage of the magnetic core by the polymer. Real-time PCR has become an effective tool for studying magnetic core encapsulation and the influence of functional groups on the surface of the polymeric layer.
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Real-time PCR and it´s use in food processing
Tomanová, Barbora ; Pravečková, Martina (referee) ; Trachtová, Štěpánka (advisor)
Polymerase chain reaction (PCR) is a method abundantly used in molecular diagnostics. PCR in real time or quantitative PCR (qPCR) is one of its modifications and thanks to its advantages it finds still wider utilization nowadays. It finds its use in the food-processing industry too with relatively precise detection, identification, and qualification of both desirable and undesirable components in food, which often brings considerable difficulties and leads to an intensive development of this method. In the experimental part a DNA was isolated from dairy product Bio Via Natur drink for its further processing by means of PCR and gain more detailed information about a bacterial composition using real-time PCR and HRM analysis.
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