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Using different methods of DNA isolation of lactic acid bacteria in molecular biological methods
Chvalkovská, Eva ; Skoumalová, Petra (referee) ; Brázda, Václav (advisor)
This thesis focused on the probiotic bacteria, DNA isolated from these bacteria by three different methods and the effect of isolation on DNA identification using molecular biological methods. Probiotic bacteria are an important part of human intestinal tract. They have an important role in the function of the immune system due to adhesion to the mucosa of the intestinal flora. They create a inhostile environment for pathogens. Probiotic bacteria are commonly taken in the food like dairy products or food supplements. However, overuse of antibiotics is at risk of passing on the intrinsic resistance that probiotic bacteria have to the pathogenic bacteria. The intrinsic resistence they have to maintain the natural homeostasis of the intestinal tract. It is important to effectively identify risky probiotic bacteria that have the ability to transmit resistance to eliminate their presence in food and dietary supplements. Three methods of DNA isolation like phenol extraction method, magnetic particle isolation and commercial kit isolation were used in the experimental part. DNA was isolated from three dietary supplements, namely Biopron 9 premium, Linex forte and GS Lactobacily forte 21. The purity and concentration of the isolated DNA was detected spectrophotometrically. The presence of individual DNA strains in dietary supplements was confirmed by real-time polymerase chain reaction. The best method of isolation in terms of purity and concentration of isolated DNA was evaluated by RT-PCR and spectrophotometry using a commercial kit isolation method.
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Characterization of adsorption properties of probiotic bacteria
Černá, Klára ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
The aim of the diploma thesis is to characterize the adsorption properties of probiotic bacteria. Characterization was performed using of designed and optimized spectrophotometric method of determination of adhesion of probiotic bacteria to mucin as the main viscoelastic component of mucus. In order to provide a more detailed description of the adhesion interactions involved in the adhesion of probiotic bacteria to mucin, the viability of selected probiotic bacterial strains Lactobacillus rhamnosus CCM 1825, Lactobacillus plantarum CCM 7039, Lactobacillus delbrueckii subsp. bulgaricus CCM 7190, Lactobacillus acidophilus CCM 4833, Lactobacillus casei CCM 4798, Bifidobacterium breve CCM 7825, Bacillus coagulans CCM 2658 and a potential probiotic strain of Lactobacillus zeae CCM 7069. Moreover, bacterial adhesion to carbohydrates was also determined for all the bacteria tested. The last proposed and optimized technique was dynamic and electrophoretic light scattering characterizing surface properties such as -potential, average size distribution and isoelectric point. From this method, information was obtained on aggregation of bacterial cells and on electrostatic interactions. The combination of these methods was used as a complex tool to characterize adhesion of the tested bacterial cultures as a very specific, sensitive and key parameter of a successful probiotic microorganism that is influence by the multiple effects.
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Viability of probiotic bacteria in some foods
Pokorná, Martina ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on viability od probiotic bacteria in some foods and looking for optimal food and beverages, that exhibited a minimal negative effect on the growth and viability of probiotic bacteria. Lactobacillus acidophilus, Bifidobacterium breve and commercially complex of probiotics were tested. In the practical part, probiotics were incubated in the environment of selected types of model and real foods. Further, incubation in model gastrointestinal juices to simulate human digestion was performed. Model foods with a moderate value of concentrations of sugar, protein and alcohol were shown the best alternative for growth of bacteria and their lowest mortality. For salt, the smallest concentration was shown as the most suitable. The chicken broth, chicken and beef meat were evaluated as the best environment for the capsule with complex probiotics. The vegetables and vegetable broth were stated like the best for Lactobacillus acidophilus and Bifidobacterium breve. According to the preliminary results we can conclude that the probiotics should be preferably consumed during meals and with the sufficient amount of liquids for the activation of all cells.
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Influence of some foods on growth and viability of probotic bacteria
Vajglová, Klára ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The goal of this work was a study the influence of food and beverages on the viability and growth of probiotic bacteria. The influence of food and beverages was tested on monocultures of Lactobacillus acidophilus, Bifidobacterium breve and mixed culture of probiotic microorganisms. In the experimental part, probiotic cultures were incubated in selected foods and beverages. After that they were tested in a model conditions of digestive tract. In some probiotic cultures, growth of viable cells during incubation in the digestive tract was observed. The increase of probiotic cells was showed predominantly in foods that contained higher levels of sugars and fats or a suitable combination. Their increase was up to four times in some cases. Based on the results, mixed probiotic cultures aren’t surprisingly exhibited better survival and maintain sufficient amount of viable cells even during the digestive process. Moreover, probiotic microorganisms could be recommended to consumption during meals better than just with a beverage.
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Microbiota of the digestive tract of bees and related insect and the influencing facftors
Hroncová, Zuzana ; Havlík, Jaroslav (advisor) ; Kalous, Lukáš (referee)
This thesis consists of six research chapters, out of which, five have already been published in research journals, 1 is in the process of submission and the last chapter presents original unpublished confidential data in the process of manuscript preparation.
The research presented in this thesis concerns the complex mechanisms of bees and wasps immune system focused on microbiota as component of immunity. As shown in the introduction, highly social and managed species of bees like honey bees and bumble bees, play key roles in natural and agricultural ecosystems worldwide. Recent losses of bees have been attributed to pesticide exposure, poor nutrition, increased parasite loads and habitat degradation. Over the past several years, governments, beekeepers, and the general public worldwide have become concerned by increased losses of honey bee colonies, calling for more research on how to keep colonies healthy. Our main aim was to explore the complex mechanisms of bees and related species gut bacterial populations, their links to insect immunity and investigate the opportunities for an intervention. Part of our aim was to characterise the bumble bee and wasp gut microbiota using 16S RNA sequencing in a search for potentially novel bacterial species.
We have tried to explain how microbiome interacts with the host and showed that major members of these communities appear to benefit the host. The simple gut communities of social bees present ideal model systems to investigate the underlying evolutionary and genetic processes of such interactions. Information based on our results may help in the design of proper probiotic supplementation strategies with respect to physiological conditions in the honey bee gut.
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Probiotic bacteria and their health importance.
ČAPKOVÁ, Martina
Nowadays probiotics and their positive effect on human health is often discussed topic. Their positive effects on the immune system and intestinal flora are proven scientifically. In recent years, potential effects of probiotics in prevention and treatment of diseases have been the centre of interest. Despite this fact public doesn´t have enough information about effects of probiotic bacteria. The theoretical part deals with a conception of probiotics, prebiotics and synbiotics, their features, effects and applications in food and health benefits. The practical part mentions results of public awareness of probiotics. 240 people, devided into 4 groups, took part in this questionnaire survey.
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