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Molecular identification of probiotic bacteria in milk products form commercial yoghurt cultures
Horňan, Samuel ; Fialová, Lenka (referee) ; Smetana, Jan (advisor)
Lactic acid bacteria are considered as an important group of bacteria with probiotic effects, which are being widely used in the food industry or pharmacology. Identification and characterization of important probiotic strains play an essential role in the validation of probiotic products for commercial purposes. Their identification using molecular-biology techniques (most commonly PCR method) is one of the standard tools in commercial operations and services. The aim of this bachelor thesis is a literature review of probiotics and probiotic strains as well as a summary of current knowledge about the use of molecular biology techniques for identification of these bacteria with probiotic properties in dairy products. The experimental part of this work verifies the presence of probiotic bacteria declared on selected commercial dairy products using the polymerase chain reaction (PCR) method.
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Detection of probiotic bacteria in diary food products using PCR technique
Klaška, Dominik ; Brázda, Václav (referee) ; Smetana, Jan (advisor)
In the bachelor thesis, DNA was isolated from commercially available white yogurt. The isolated DNA, which was gained by two different methods, was performer analyse by a spectrophotometer. Both methods provided sufficiently concentrated and high-quality DNA for further analysis by PCR. Precisely defined sections of isolated DNA were amplified using specific primers. The presence of the bacterium domain was detected, and in the case of genus specific amplification, the presence of bacteria of the genus Lactobacillus was detected too, by gel electrophoresis.
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The used of magnetic microparticles for isolation and prove of probiotic bacterial DNA in meat
Vašíček, Roman ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
This thesis deals with the isolation of probiotic DNA from meat products and its assesment by PCR methods. In this thesis is developed homogenization of samples of sausages with kopist, preparation of sausage cells lysates and isolation of DNA by using of magnetic microparticles. The DNA was isolated from sausage lysates by using magnetic microparticles. Isolated DNA was further amplified in genus and spesies-specific PCR methods. In tested products was proven presence of DNA of domain Bacteria, type Lactobacillus and Bifidobacterium. In one product was proven presence of species Lactobacillus acidophilus and Bifidobacterium animalis.
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Sample preparation for DNA analysis from foods of plant origin
Silná, Renata ; Rittich, Bohuslav (referee) ; Kovařík, Aleš (advisor)
The isolation of high quality DNA is nessecary for many molecular biology applications. However, plant DNA contains high amonts of polysaccharides, polyphenols and various secondary metabolites, which decrease yield and quality of isolated DNA. The aim of this study was preparation of samples and different food matrices for DNA isolation DNA by magnetic particles. It was about 5 species of vegetable and 10 species of processed plant food. Homogenization of samples was performed in CTAB buffer. Isolation of plant DNA was performed by magnetic particles covered with carboxyl groups. All DNAs were isolated in conventional PCR qualities using primers for 700 bp amplicons, in the case of heat processed products for 220 bp ampilicons and for real time PCR. The efficiancy of separation of magnetic particles with DNA by magnetic separator and magnetic needle was compared. It was find out that DNA of higher purity was isolated using magnetic needle. The micromethod of isolation of plant DNA from homogenates with CTAB with magnetic particles is suitable for different processed food.
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Evaluation of a micromethod for isolation of DNA from plant leaf, fruit and fruit products
Balažovičová, Nikola ; Rittich, Bohuslav (referee) ; Kovařík, Aleš (advisor)
The thesis has been focused on testing of micromethod of DNA isolation from leaves, fruits and fruit products. Jams were selected for the analysis of plant DNA in technologically processed foods. Plant leaves, fruits, and jams were homogenized using plastic copist in a lysis buffer containing 2% cetyltrimethylammonium bromide (CTAB) with 2.5M sodium chloride (NaCl). Microisolation of plant DNA was performed using poly(hydroxyethylmethacrylate-co-glycidylmethacrylate) – P(HEMA-co-GMA)microparticles. Isolated the DNA concentration and purity were assessed by UV light aborbance using a spectrophotometer. After that, amplification of the DNA was tested in PCR. Primers specific for plant ribosomal DNA: 18S_for a 5,8S_rev (PCR product - 700bp), 26S_for a 26S_rev (PCR product - 220 bp), 18S_for a 18¬S_rev (PCR product - 263 bp) were used. The PCR conditions were optimized and the effect of the amplicon length on its detection was followed. PCR products were detected by agarose gel electrophoresis. It was shown that DNA isolated from almost all of leaves using magnetic particles was in PCR-ready quality in contrary to the fruits. DNA amplified in PCR with primers giving short PCR products was isolated from almost all tested jams. The method must be optimalised, yet.
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DNA isolation from selected vegetable products (paprika)
Gőghová, Sabína ; Kuderová,, Alena (referee) ; Kovařík, Aleš (advisor)
The diploma thesis deals with micromethod of DNA isolation from ten differently processing food products containing pepper (Capsicum annum). PCR ready DNA was isolated by magnetic particles PGMA functionalized by carboxyl groups from homogenates prepared in lysis buffer with CTAB. Quantity and quality of DNA was estimated using spectrophotometric measurements and verified using PCR methods with primers specific for plant rDNA. Quality of isolated DNA varied depending on processing technology. DNA isolated from smoked grinded peppers and from heat treated food products was degraded and amplified with primers F_26S and R_26S (PCR product 220 bp) in contrary to the primers F_18S and R_5.8S (PCR product 700 bp). DNA isolated from the other food products was amplified with primers F_18S and R_5.8S (PCR product 700 bp). PCR product from one grinded pepper (Žitavská paprika) was cloned and sequenced.
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Optimalisation of a new micromethod of DNA isolation from foods
Surá, Tereza ; Rittich, Bohuslav (referee) ; Španová, Alena (advisor)
The thesis were focused on the optimalization of micromethod for isolation of DNA in quality for polymerase chain reaction (PCR) using magnetic microparticles from plant food products. There were chosen a red beetroot (fresh, frozen, dried and sterilized) for the analysis and food products containing red beetroot. Different approaches of processing of homogenates were compared and optimized. The homogenates were prepared in lysis buffer with cetyltrimethylammonium bromide (CTAB) with different amounts of NaCl with or without addition of organic extraction agents chloroform-octanol and isopropanol. Microisolation of DNA was performed using magnetic particles P(GMA). The concentration of NaCl and polyethylene glycol (PEG) 6000 in separation mixtures was tested. The influence on quantity and purity of isolated DNA was compared and the optimum amounts of NaCl in CTAB buffer and optimal concentration of PEG 6000 in separation mixtures were compared. The optimized separation mixture for the DNA isolation from red beetroot was applied to food products containing red beetroot. Amplifiability of DNA was tested in conventional PCR using specific primers for plant DNA. PCR products of length 700 bp were detected by agarose gel electrophoresis.
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The application of magnetic particles for DNA isolation from thermally processed food products
Hronová, Aneta ; Rittich, Bohuslav (referee) ; Kovařík, Aleš (advisor)
The thesis has been focused on testing of micromethod of DNA isolation using magnetic particles from thermic-managed food products in a quality suitable for polymerase chain reaction (PCR). Currant jams were selected for the analysis. These were homogenized using plastic copist and stomacher in lysis buffer with cetyltrimethylammonium bromide (CTAB). The effect of chloroform-octanol and isopropanol in the preparation of homogenates was tested. Homogenates were used for DNA isolation by magnetic particles. Rough fraction of DNA was purified by binding on the magnetic particles after centrifugation of the CTAB complexes with proteins, polyphenols and polysaccharides. Two types of magnetic particles were tested: microparticles of poly(hydroxyethylmethacrylate-co-glycidylmethacrylate) - P(HEMA-co-GMA) and nanoparticles of iron oxides covered by poly(L-lysine) - PLL. Isolated DNA was analyzed spectrophotometrically - it was assessed its concentration and contamination by polyphenols and proteins. After that, amplification of the DNA was tested in PCR. Primers specific for plant ribosomal DNA were used. PCR products of expected length 700 bp were detected by agarose gel electrophoresis. It was shown that DNA isolated from currant jams using magnetic particles was in PCR-ready quality.
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The application of magnetic particles for DNA isolation from cereal products
Starenkova, Anastasiia ; Španová, Alena (referee) ; Rittich, Bohuslav (advisor)
The thesis has been focused on micro method for isolation of PCR- ready DNA iusing magnetic particles from cereal products. Cereal biscuits and cereal products for babies were selected for the analysis. These were homogenized using plastic copist in lysis buffer with cetyltrimethylammonium bromide (CTAB). The homogenates were purified using chloroform- octanol mixture. The effect of isopropanol in the preparation of homogenates was tested, too. Homogenates were used for DNA isolation by magnetic particles. Two ways to isolate magnetic particles with bounded DNA (magnetic separator and magnetic needle have been tested. Isolated DNA was analyzed spectrophotometrically its concentration and purity were assessed. . After that, amplification of the DNA was tested in PCR. Two sets of primers specific for plant ribosomal DNA were used for their amplification. PCR products of expected length 700 bp and 220 bp were detected by agarose gel electrophoresis. It was shown that DNA isolated from seeds and cereal products using magnetic particles was in PCR-ready quality.
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Study of the effect of cosmetics on the human skin microbiome using molecular techniques
Alexová, Adéla ; Kovalčík, Adriána (referee) ; Němcová, Andrea (advisor)
The theoretical part of the thesis is focused on the basic description of the physiology of the skin, human microbiome and a brief summary of where individual microorganisms occur. Furthermore, there is a list of analytical and microbiological methods that are used in this thesis. In the beginning, the practical part is focused on determination of antimicrobial effects of the chosen cosmetic products using microbial tests. Then, the inhibiton and microbial effect of the chosen cosmetic products on examined microorganisms has been measured using ELISA method. The second part of the thesis is focused on the isolation of bacterial DNA in quality that would be high enough to be used for amplification in PCR. There has been an optimalization of isolation of microbial DNA that was to be found on tested subjects’ skin. The presence of chosen microorganisms on skin before and after the usage of cosmetic products was measured using a PCR method. PCR products were then detected using gel electrophoresis. From the gathered data it is clear that the number of observed microorganisms has changed significantly after the application of cosmetic products.
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