National Repository of Grey Literature 36 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Production of magnetic particles by microorganisms
Chvalkovská, Eva ; Mgr. Martina Mikešová, Ph.D. (roz. Pravečková) (referee) ; Trachtová, Štěpánka (advisor)
This thesis focuses on the magnetic nanoparticles produced by bacteria. These are two types of bacteria. First of them we can find in an industrial environment that produce magnetic nanoparticles using magnetosomes. Magnetosomes are units containing nanocrystals and are surrounded by a lipid layer. They are made up of chains and work as a compass. In this thesis I deal with possibilities of cultivation od these bacteria, acquisition of magnetosomes and subsequent processing. The second type is bacteria living in the human body, they start to produce magnetic nanoparticles after the addition of trigger, such as silver nitrate. Bakteria which can produce silver or ferrous nanoparticles are Bacillus sp, Escherichia coli, Lactobacillus casei ssp. casei and Lactobacillus fermentum. Experimental part of bachelor thesis focused on the production of silver nitrate in concetration of 0,1; 1; 2; 4 mM. The bacteria that have been shown to produce silver nanoparticles are Lactobacillus casei ssp. casei CCM 7088T a Lactobacillus casei ssp. casei CCM 7089 a Lactobacillus rhamnosus CCM 1825T.
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.
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.
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.
Identification of microorganisms in cosmetic products with probiotics
Romanovská, Denisa ; Španová, Alena (referee) ; Trachtová, Štěpánka (advisor)
Probiotics products are an integral part of the current market. Products containing probiotics cultures are also cosmetic products. The first part of the study focuses on testing of bacterial survival abilities in the environment of preservatives presented in cosmetic products. Collection strains of genus Lactobacillus were used for these tests. Another part of the study focuses on isolation of bacterial DNA from probiotic cosmetic products Ryor, Yoghurt of Bulgaria, FeminaMed and Lactovit Activit in PCR-ready quality. DNA was isolated by fenol extraction and with magnetic particles. Presence of bacteria was proved by genus and species specific PCRs Lactobacillus. Species specific PCR for identification of Lactobacillus pentosus was optimalized. Species identification was in accord with data declared by producers.
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.
Properties of probiotics used in food and their safety
Koplík, Jerguš ; Němcová, Andrea (referee) ; Trachtová, Štěpánka (advisor)
The thesis deals with the criteria and the properties which the microorganisms must fulfill to be included among the probiotics. After it deals with the assessing of the safety of probiotic strains used in the food industry nowadays and their potential negative influence on the food quality and the human health. Then the thesis defines the kind of cheese Bryndza like the potential probiotic product. It focuses on the microbial composition, the process passing during the production and the general qualities of this kind of regional food. The aim was to analyse microflora of cheese Bryndza and that´s why PCR was carried out in the real time by using primers, which are typical for domain Bacteria, total yeasts and genus Lactobacilli. Three different samples of cheese Bryndza were analysed. DNA was isolated by two types of magnetic carriers. To find out the particularities of these products the analysis of the melting curve was carried out and its results were verified by the gel electrophoresis. The existence of bacterial DNA and lactobacilli was proved in two samples. In the third one there was lower, even no concentration. The existence of yeasts was not proved only in one of the samples.
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).
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.
Isolation of yeasts from the vineyard and their using in the production of wine
Ždiniaková, Tereza ; Trachtová, Štěpánka (referee) ; Vránová, Dana (advisor)
The aim of this thesis was the isolation and identification of yests obtained from the wine berries by different molecular methods. The yeasts for identification were collected from the species of Veltlínské zelené white wine from the wineyard from Milotice, district Hodonín. Identification based on analysis DNA by PCR method and followed by RFLP using restriction enzymes HaeIII, HinfI, HhaI a TaqI. To obtain values lenghts of the restriction fragments was used gel electrophoresis. For getting genetic similarity of analyzed yeasts was used BioNumerics software, that processe the results using cluster analysis using Jaccard´s coefficients and the yeasts were identified by comparing the characteristic lenghts with number of articles and educational databases.

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