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Beer foam stabilization using biosurfactants
Jandrtová, Sabina ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis focuses on a research of the foam stability of the beer. We specifically observed the influence of ethanol and surface tension on the foam stability, and influence of ethanol and surface tension on the height of the foam. It was observed the influence of the hop acids in non-alcoholic beers. Furthermore, different biosurfactants were added into to the beer to observe better stability of the foam. The theoretical part of this work describes the foam from the physical aspect. There are described fourth key events involved in foam formation. Then it focuses on the beer foam – its structure, substances that influence its behavior and measurement of the foam stability. In this part there are described biosurfactants as well – their characteristics, qualities, distribution and applications. The experimental part is dedicated to the influence of ethanol, surface tension, the amount of iso- acids on foam stability in beer. There is observed the influence of biosurfactants of the foam stability and surface tension, which are added into to the beer. For the measurement of the foam stability was used the Rudin method. Liquid chromatography with DAD detector was used for the measurement the amount of the hop acids. The surface tension was determined by tensiometer. According to the results addition of ethanol changed the characteristics of the foam stability, but it’s not easy to find correlation between the increasing amount of ethanol and its stability. It was found out, that there is connection between the amount of ethanol and surface tension. On the other hand, there is not much connection between the surface tension and foam height. Within the framework of addition of biosurfactants was observed, that these foaming agents interacted the surface tension of the beer (lowering), however these agents accelerated the fall of the beer foam.
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Production and characterization of biosurfactants
Kratochvílová, Olga ; Samek, Ota (referee) ; Obruča, Stanislav (advisor)
This diploma thesis deals with the microbial production of biosurfactants of selected bacterial strains. In order to test the biosurfactant production ability, screening methods were chosen to be able to review the potential of the selected strains to produce biosurfactants. With the scope of the work, 11 bacterial strains, which are used as polyhydroxyalkanoate (PHA) producers, have been tested. The ability to produce biosurfactants was tested in all strains both in complex inoculation and mineral production media. The presence of biosurfactants in Pseudomonas putida was detected on the basis of the results obtained after cultivation in inoculation and production media. The bacteria Pseudomonas fulva was put under more deep study to support their production by cultivation in different types of production media supplemented by different sources of carbon and nitrogen, and the effect of cultivation time was tested as well. Biosurfactants produced by these bacteria were subsequently identified by Fourier transform infrared spectroscopy (FTIR) on the basis of which the substances were identified as rhamnolipids. According to thin-layer chromatography result (TLC), Pseudomonas putida produces a mixture of mono- and dirhamnolipids, with monorhamnolipids being more dominant in our samples.
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Study on biotechnological potential of Pseudomonas thermotolerans
Vašířová, Kristýna ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
The aim of this bachelor‘s thesis was to evaluate biotechnological potential of the bacterium Pseudomonas thermotolerans. The ability of bacterium to produce polyhydroxyalkanoates (PHA) and biosurfaktants was examined. Theoretical part deals with characteristic of extremophilic bacteria, PHA and biosurfactants. In the experimental part, the bacterium was tested for the presence of gene that catalyzes the synthesis of mcl-PHA (phaC1), using molecular technique PCR. Presence of the gene was confirmed by the experiment. Based on the result, PHA production conditions were optimized, such as selection of ideal media for production, suitable cultivation temperature and precursors. However, non of the tests confirmed the ability of production. Another of the experiments was to examine the bacterium’s ability to produce biosurfactants. Testing was realized in a suitable mineral medium with different carbon sources. Demonstrable production of biosurfactants was only on mineral medium supplemented by yeast extract and fructose. The thin layer chromatography (TLC) demonstrated, that the bakterium produces a mixture of monorhamnolipids and dirhamnolipids. However, higher portion is represented by dirhamnolipids.
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Beer foam stabilization using biosurfactants
Jandrtová, Sabina ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis focuses on a research of the foam stability of the beer. We specifically observed the influence of ethanol and surface tension on the foam stability, and influence of ethanol and surface tension on the height of the foam. It was observed the influence of the hop acids in non-alcoholic beers. Furthermore, different biosurfactants were added into to the beer to observe better stability of the foam. The theoretical part of this work describes the foam from the physical aspect. There are described fourth key events involved in foam formation. Then it focuses on the beer foam – its structure, substances that influence its behavior and measurement of the foam stability. In this part there are described biosurfactants as well – their characteristics, qualities, distribution and applications. The experimental part is dedicated to the influence of ethanol, surface tension, the amount of iso- acids on foam stability in beer. There is observed the influence of biosurfactants of the foam stability and surface tension, which are added into to the beer. For the measurement of the foam stability was used the Rudin method. Liquid chromatography with DAD detector was used for the measurement the amount of the hop acids. The surface tension was determined by tensiometer. According to the results addition of ethanol changed the characteristics of the foam stability, but it’s not easy to find correlation between the increasing amount of ethanol and its stability. It was found out, that there is connection between the amount of ethanol and surface tension. On the other hand, there is not much connection between the surface tension and foam height. Within the framework of addition of biosurfactants was observed, that these foaming agents interacted the surface tension of the beer (lowering), however these agents accelerated the fall of the beer foam.
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|
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Study on biotechnological potential of Pseudomonas thermotolerans
Vašířová, Kristýna ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
The aim of this bachelor‘s thesis was to evaluate biotechnological potential of the bacterium Pseudomonas thermotolerans. The ability of bacterium to produce polyhydroxyalkanoates (PHA) and biosurfaktants was examined. Theoretical part deals with characteristic of extremophilic bacteria, PHA and biosurfactants. In the experimental part, the bacterium was tested for the presence of gene that catalyzes the synthesis of mcl-PHA (phaC1), using molecular technique PCR. Presence of the gene was confirmed by the experiment. Based on the result, PHA production conditions were optimized, such as selection of ideal media for production, suitable cultivation temperature and precursors. However, non of the tests confirmed the ability of production. Another of the experiments was to examine the bacterium’s ability to produce biosurfactants. Testing was realized in a suitable mineral medium with different carbon sources. Demonstrable production of biosurfactants was only on mineral medium supplemented by yeast extract and fructose. The thin layer chromatography (TLC) demonstrated, that the bakterium produces a mixture of monorhamnolipids and dirhamnolipids. However, higher portion is represented by dirhamnolipids.
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Production and characterization of biosurfactants
Kratochvílová, Olga ; Samek, Ota (referee) ; Obruča, Stanislav (advisor)
This diploma thesis deals with the microbial production of biosurfactants of selected bacterial strains. In order to test the biosurfactant production ability, screening methods were chosen to be able to review the potential of the selected strains to produce biosurfactants. With the scope of the work, 11 bacterial strains, which are used as polyhydroxyalkanoate (PHA) producers, have been tested. The ability to produce biosurfactants was tested in all strains both in complex inoculation and mineral production media. The presence of biosurfactants in Pseudomonas putida was detected on the basis of the results obtained after cultivation in inoculation and production media. The bacteria Pseudomonas fulva was put under more deep study to support their production by cultivation in different types of production media supplemented by different sources of carbon and nitrogen, and the effect of cultivation time was tested as well. Biosurfactants produced by these bacteria were subsequently identified by Fourier transform infrared spectroscopy (FTIR) on the basis of which the substances were identified as rhamnolipids. According to thin-layer chromatography result (TLC), Pseudomonas putida produces a mixture of mono- and dirhamnolipids, with monorhamnolipids being more dominant in our samples.
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