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The characterisation of selected type of „bio“ dairy product
Hanychová, Silvie ; Trachtová, Štěpánka (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the sensory evaluation of kefir. Specifically the differences in the sensory properties of kefir produced using the same method from various types of milk were observed. The theoretical part was focused on kefir, its characteristics, composition and production using kefir grains. The experimental part deals with the comparison of four kefir samples based on sensory evaluation. The evaluation was made by the students from Faculty of Chemistry BUT, the untrained assessors. Therefore the evaluation results may be closely reflecting the opinions of common consumers. The samples of kefir were subjected to sensory evaluation by the ranking test and the pleasantness of chosen properties (appearance, colour, texture, odour and taste) was evaluated using a seven-point scale, as well as the overal acceptability of samples. The results were statistically processed and graphically evaluated.
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Non-traditional foods containing probiotic bacteria
Sobotková, Markéta ; Konečná, Jana (referee) ; Trachtová, Štěpánka (advisor)
Probiotic microorganisms are contained in common dairy products as well in unconventional probiotic products consumed especially in Asian countries. In the thesis is shown overview of chosen less common foodstuffs containing probiotic microorganisms, which no belong to fermented dairy products. In the thesis are discussed positive health benefits of probiotics foodstuffs on the host. The experimental part deals with the identification of probiotic microorganisms, which are contained in chosen probiotic product from Asia. DNA was isolated from the product by use phenol extraction and using magnetic particles. Probiotic microorganisms in chosen product were detected using method real-time polymerase chain reaction (qPCR).
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Pretreatment of polysaccharide waste materials to maximize of hydrolysis products
Myslivcová, Pavla ; Trachtová, Štěpánka (referee) ; Babák, Libor (advisor)
This thesis deals with study of the polysacharidic waste material pretreatment in order to maximize the hydrolysis products. It has been chosen a pastry as a waste material, specifically rolls and bread. Pastry was pretreated by milling and 15% w/v suspension of pastry in the water was prepared. Then several types of hydrolysis were performed with suspensions. Products of hydrolysis were characterized by spectrophotometric method of Somogyi-Nelson and efficiency of hydrolysis was compared. Three acids (H2SO4, HNO3, HCl) and two alkalis (NaOH, KOH) in three various concentration were used for the chemical hydrolysis. Microwave and ultrasound were chosen for the physical hydrolysis.
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Lactobacillus DNA analysis using real-time PCR and HRM analysis
Aksamitová, Dagmar ; Illková, Kateřina (referee) ; Trachtová, Štěpánka (advisor)
The rapid and accurate identification of the bacterium of the genus Lactobacillus, which are an important part of the normal gastrointestinal microflora and fermented dairy products are currently mainly used amplification methods. The aim of the study was to analyze the possibility of resolution of selected bacterial strains of the genus Lactobacillus, using the metod of polymerase chain reaction in the real time combined with high resolution melting curve analysis (qPCR HRM). It was tested five primers designed for qPCR-HRM analysis of lactic acid bacteria. The specificity of the primers was also verified simultaneously using bioinformatic analysis. On the basis of analysis of the DNA were selected as the most appropriate primers P1V1/P2V1, V3F/V3R and V6F/V6R. The suitability of the primers V3F/V3R and V6F/V6R was verified on a complex sample of food supplement from which the DNA was isolated using magnetic particles. The presence of bacteria of the genus Lactobacillus was performed using high resoluting melting analysis curves. The obtained results were in agreement with the information given by the manufacturer.
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Microbiological analytical methods suitable for dairy industry
Vlasák, Jaroslav ; Illková, Kateřina (referee) ; Trachtová, Štěpánka (advisor)
The theoretical part of the thesis is focused on probiotics in dairy products. Thesis deals with molecular genetic methods, which are used to analyze DNA. Especially are discussed methods used for isolation bacterial cells belonging to genus Lactobacillus. The polymerase chain reaction (PCR) is the basic technique at present time. Short chain of oligonucleotide primers are used to amplification specific parts of DNA molecule chain. The practical part of the thesis is focused on the DNA from pure bacterial culture and probiotic dairy product. DNA was isolated using methods of phenol-chloroform extraction and magnetic separation. For magnetic separation was used magnetics particles covered with carbonyl functional groups. Quality of the DNA was confirmed by PCR amplification. Primers specific for domain Bacteria and genus Lactobacillus and Bifidobacterium was used.
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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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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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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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