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Use of stress factors for the production of lipid substances by yeasts of the genus Metschnikowia
Tručková, Marie ; Márová, Ivana (referee) ; Němcová, Andrea (advisor)
This Master´s thesis consists of two parts. The theoretical part is focused on the influence of various stress factors in the cultivation process, such as osmotic stress, oxidative stress, dehydration, cultivation time, pH or temperature on yeasts of the Metschnikowia genus. The practical part deals with osmotic and oxidative stress. Oxidative stress was performed under two different conditions (various cultivation time and temperature). The properties of yeast production were monitored mainly by gas chromatography and marginally also by flow cytometry. The analysis was performed for Metschnikowia pulcherrima, Metschnikowia andauensis, Metschnikowia chrysoperlae, Metschnikowia sinensis, Metschnikowia zizyphicola and Metschnikowia shanxiensis strains. The results showed that both oxidative stress and osmotic stress induce better lipids production. The amount of lipids, especially the fatty acid composition, also varied depending on the strains studied and the culture conditions used. The production of unsaturated fatty acids was further demonstrated in this work. The most suitable medium for the production of lipids and unsaturated fatty acids was the salt medium. It is clear that yeasts of the genus Metschnikowia are highly adaptable yeasts. Therefore, they might be potentially auspicious biotechnology producers.
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Knowledge of substitutes of salt in food
Vaňková, Marie ; Váchová, Alena (advisor) ; Hanušová, Jaroslava (referee)
The diploma thesis deals with the issue of salt and possibility of its replacement in food. The chosen is topical because healthy nutrition is one of current modern trends. Table salt is an entire part of a diet of every person. As the compound of two biogenic elements - sodium and chlorine - it has unsubstitutable function in human body. However, an increased intake of sodium can be associated with health risks, especially hypertension. The World Health Organization recommends a maximum daily intake of salt 5 g. According to current statistics, nevertheless the salt intake in the Czech republic is up to three times higher. Therefore, it is appropriate to reduce the consumption of salt and attempt to its replacement without cutting down the taste of food. One of the goals of this thesis was find out possibilities of replacing the salt and what is their availability. The practical part deals with the results of survey, within these was examined the awareness of salt and the posibility of its replacement among different group of our population (students, pedagogical workers, heads of school canteens). In terms of established facts there was suggested a project called The salt is beneficial and dangerous which aids to raise awareness of students about this topic. These outputs can be put into the...
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Study on PHA accumulation by cyanobacteria
Pacasová, Viktorie-Alexandra ; Slaninová, Eva (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis was focused on studying the influence of selected stress factors on PHB production in strains of cyanobacteria Synechocystis sp. PCC 6803 and Synechocystis salina CCALA 192. Cyanobacterial stains were cultivated in multicultivator and as a stress factor an increased salt (sodium chloride) as well as a mixture of acetate and -butyrolactone was selected. The PHB content in cyanobacteria was determined by gas chromatography. In addition, the content and presence of pigments in cyanobacteria strains was determined by pigment extraction as well as using direct spectroscopy of whole cells. When cultivated with an increased salinity, the hypothesis of an increased PHB production was not confirmed most likely due to and overstressing the Synechocystis salina CCALA 192 cultures with increased salt content, constant illumination of multicultivator and by nitrogen limitation due to the used medium. When cultivated with the mixture of acetate and -butyrolactone the stains were analysed in the same way as in the cultivation with an increased salinity. In this case, the presence of 3-hydroxybutyrate and 4-hydroxybutyrate copolymer was determined in the stain cultivated with the mixture of acetate and -butyrolactone. During this cultivation, a positive effect of initial concentration of cells in the cyanobacterial cultures combined with continuous illumination and the type of nitrogen-limiting type of medium on the growth rate of selected stains was observed.
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Production technology of wine sausage with reduced salt content
Martonová, Rebeka ; Punčochářová, Lenka (referee) ; Mikulíková, Renata (advisor)
The aim of this bachelor thesis was preparation of wine sausages with reduced salt content, followed- up by sensory analysis. The theoretical part generally characterizes meat and meat products, sodium chloride and its importance in food. In the next chapters, the paper deals with sensory analysis of samples and analytical method for determining the concentration of elements in biogenic samples, in particular inductively coupled plasma - optical emission spectrometry. The experimental past focuses on the evaluation of data from sensory analysis using the Kruskal- Wallis and Spearman test. The samples were analyzes using ICP-OES method. The analysis determined the concentration of sodium and potassium in the samples before and after roasting.
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Salt content in food and its intake in the Czech Republic
Olišarová, Anna ; Dostálová, Jana (advisor) ; Chrpová, Diana (referee)
This bachelor thesis deals with the salt content in food and its intake in the Czech Republic. The consumption of salt in the Czech Republic allows up to three times the recommended amount of salt per a day. The companies such as the WHO, EU, EFSA, WASH, SPV and others have been trying to reduce it for a long time. The food reformulation is providing to be the most effective tool for reducing salt consumption. The theoretical part describes salt legislation, the effect of sodium chloride on the human body. It shows what happens when there is lack or excess of sodium in the body. Furthermore, the possible risks of excessive salt consumption are described. There is explained the use of salt in the food industry and the food technology. Food commodities that are important sources of salt, such as bread and pastries, meat products and some types of cheese, are described. The reformulation of food and the efforts of food producers to reduce salt in their products are also presented. The recommended amount of salt and the current production and consumption of salt are also presented. The aim of the practical part is to find out what is the awareness of population of the Czech Republic about the amount of salt in food, their own salt consumption, knowledge of the recommended amount of salt per day and...
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Diagnostics of Diaphragm Discharge in Water Solutions and its Application for the Nanomaterials Surface Treatment
Dřímalková, Lucie ; Brablec, Antonín (referee) ; Janda,, Mário (referee) ; Krčma, František (advisor)
The exact mechanism of the discharge in liquids ignition is not sufficiently known up to now. Although during the last years was achieved the great progress and overloading which some of them are written in this theoretical part of thesis. This thesis is divided into two experimental parts. When the first part deals with diagnostics of diaphragm discharge in electrolyte solutions and the second part is focused on its use for uncoiling (higher homogenization) of carbon nanotubes in solutions. In experiment 1, three different sized (4 l, 100 ml, 50 ml) diaphragm discharge configurations were used to diagnose diaphragm discharge in electrolyte solutions. Diagnostics is done through current and voltage waveforms with the addition of synchronized ICCD camera images that have been connected to a four-channel oscilloscope. The V-A characteristic can be described by three events occurring in the electrolyte solution with a gradual increase in voltage. Slowly increasing of the voltage in the solution leads first to electrolysis. The next phase is the formation of microbubbles or bubbles, which is characteristic of the curve by a slight decrease in the increase of the current passing between electrodes. The sudden increase in the current flow is characteristic of the last phase, namely the discharge phase. The distance of the electrodes from the diaphragm does not significantly affect the V-A characteristic. The higher diameter of the pin hole, therefore, has a higher voltage, but this does not affect the origin of bubble generation or breakdown. The higher thickness of diaphragm, the higher voltage is needed to the beginning of the bubbles generation, and consequently the discharge breakdown. Comparison of the voltage of the start generation of the bubbles and breakdown for PET diaphragms and diaphragms from the ceramic there was no mark able difference. One of the most important parameters is the conductivity of the electrolyte solution. The lower voltage is needed for the start generation of the bubbles at the higher solution conductivity, and also the discharge generation is observed at a lower breakdown voltage. The second experimental part is focused on the study of the diaphragm discharge effect on carbon nanotubes. A specially designed U-shaped reactor is used to modify carbon nanoparticles. Tap water and aqueous solutions of organic compounds are used as the electrolytic solutions. The discharge is generated by a non-pulsed DC high source with a voltage in the range of 0-2.8 kV supplied to platinum electrodes located in the electrolyte solution. The experimental results have shown that the diaphragm discharge has positive effects on the disintegration of clusters and agglomerates of carbon nanotubes. The primary effect on disintegration is probably the shock waves generated by the discharge. It turned out that it depends on the electrode configuration, where the treatment in anode space has far greater effects than the treatment in cathode half of the reactor. Effects of carbon nanotubes disintegration in solution are long-lasting and the treatment effect is not loosed after several months. There were detected no significant changes in the structure of plasma-treated nanotubes by Infra-red spectroscopy.
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Health aspects of salt in food
Wűrzová, Anna ; Bušová, Milena (advisor) ; Králíková, Eva (referee)
Sodium chloride is an integral part of our nutrition and has an important function in the metabolism of the human organism. It contains sodium which is one of the basic minerals of the body. Although the salt is necessary for our body, its excess intake leads to a number of negative health effects. The theoretical part of the thesis describes the physiological importance of sodium chloride and the negative effect of salt on the body. It also deals with legislative requirements for salt, the recommended daily doses and trends in the consumption of salt. Last but not least, inform about therapeutic nutrition and the prevention of diseases associated with excess salt intake. The aim of the work is to make an overview of the importance and use of salts and the negative health effects of excess salt in human nutrition and further laboratory verification of the salt content in selected food and compared the measured results with the data on the salt content listed on the packaging. Part of the work is sample menus with different content of salt. The assembled full-day menus using the program Nutriservis represent, how to eat properly and to follow the health recommendations for salt intake according to the WHO and at the same time contain examples of bad menus with overdue daily amount of salt. For...
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Crystallization force of sodium chloride
Koudelková, Veronika ; Wolf, Benjamin
Soluble salts are one of the most deteriorating factor causing damage of historical building materials due to generation of crystallization pressure inside pore space. Direct measurement of crystallization force is quite challenging, hence we developed at our institute a novel device able to detect the force of growing crystal. The device is based on the monitoring of force developed with upper microscopic glass on the growing crystal to maintain constant position. The crystal could generate force because of the existence of thin liquid layer of solution between both surfaces come into contact. The driving force for the subsequent growth of crystal against obstacle is supersaturation, which is mainly induced by evaporation of the salt solution. In this experiment, the crystal of sodium chloride generated force 16.8 mN and the corresponding crystallization pressure was equal to the value 0.48 MPa.
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Knowledge of substitutes of salt in food
Vaňková, Marie ; Váchová, Alena (advisor) ; Hanušová, Jaroslava (referee)
The diploma thesis deals with the issue of salt and possibility of its replacement in food. The chosen is topical because healthy nutrition is one of current modern trends. Table salt is an entire part of a diet of every person. As the compound of two biogenic elements - sodium and chlorine - it has unsubstitutable function in human body. However, an increased intake of sodium can be associated with health risks, especially hypertension. The World Health Organization recommends a maximum daily intake of salt 5 g. According to current statistics, nevertheless the salt intake in the Czech republic is up to three times higher. Therefore, it is appropriate to reduce the consumption of salt and attempt to its replacement without cutting down the taste of food. One of the goals of this thesis was find out possibilities of replacing the salt and what is their availability. The practical part deals with the results of survey, within these was examined the awareness of salt and the posibility of its replacement among different group of our population (students, pedagogical workers, heads of school canteens). In terms of established facts there was suggested a project called The salt is beneficial and dangerous which aids to raise awareness of students about this topic. These outputs can be put into the...
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Use of energetic by-products and other secondary raw materials for the alpha gypsum production
Moldrzyk, Jan ; Jiroušková, Kateřina (referee) ; Dvořák, Karel (advisor)
Thesis focus on the longterm research in an area of alpha gypsum production by non pressure method in chloride salt solutions production, which is researched by Institute od technology of building materials and components, Faculty of civil engineering for many years. The result of given research is non pressure equipment for alpha gypsum production. The scope of this research was to make a production of alpha gypsum more efficient through modification of the facility itself and through an optimalization of dehydration process. The scientific aim of this process was to compare an influence of dehydratation solutions of CaCl2, NaCl and KCl on the final product provided that molarity of solutions was at the same level.
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