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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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A novel way of preparing hydrogels
Kratochvílová, Olga ; Smilek, Jiří (referee) ; Mravec, Filip (advisor)
This work is focused on testing the effect of ionic strength on the preparation of hydrogels prepared by phase separation hylauronanu polyelectrolyte solution (Hya) with cationic surfactant cetyltrimethylammonium bromide (CTAB) called „dry way“. In this case, there is a mixing of the polymer and the surfactant in the dry form and then added to the dispersion medium. With observation and rheology, the effects of the proportion of the components for the formation of the hydrogel. It was found that the higher the ionic strength causes the hydrogel has a lower viscosity and a more fluid. Tthis fact was confirmed from the results of rheological measurements. The gel with the ionic strength of 1 M is less viscous to gel the ionic strength of 0,5 M. Next, the purity of the hydrogel was observed, and it was found that hydrogels with the ionic strength of 0,15 M are clear without the use of centrifugation. In case of getting gel of the specific ionic forces of 0,15 M and 0,3 M formed by addition of multivalent cations/anions from observations we can say that the ionic strength in the case of the method of preparation of gels does not matter.
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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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The issue of loans in the banking and non-banking sector
Kratochvílová, Olga ; Cvik, Eva Daniela (advisor) ; Pikola, Pavel (referee)
This Bachelor Thesis is focused on the issue of credit products in banking and non-banking sector in the Czech Republic. The first part introduces the theory related to explanation keywords, description of the credit products which are currently offered on the Czech market and which are linked with the legislative interpretation of relevant terms related to the credit issues. The practical part includes description of the credit products by leading representatives of the banking and non-banking sector, comparison of consumer credit, questionnaires and interviews with employees representing selected financial institutions. Author's own experience and the analysis of accomplished investigation helped to design an innovative loan products that could use its parameters to provide clients with more favorable conditions.
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A novel way of preparing hydrogels
Kratochvílová, Olga ; Smilek, Jiří (referee) ; Mravec, Filip (advisor)
This work is focused on testing the effect of ionic strength on the preparation of hydrogels prepared by phase separation hylauronanu polyelectrolyte solution (Hya) with cationic surfactant cetyltrimethylammonium bromide (CTAB) called „dry way“. In this case, there is a mixing of the polymer and the surfactant in the dry form and then added to the dispersion medium. With observation and rheology, the effects of the proportion of the components for the formation of the hydrogel. It was found that the higher the ionic strength causes the hydrogel has a lower viscosity and a more fluid. Tthis fact was confirmed from the results of rheological measurements. The gel with the ionic strength of 1 M is less viscous to gel the ionic strength of 0,5 M. Next, the purity of the hydrogel was observed, and it was found that hydrogels with the ionic strength of 0,15 M are clear without the use of centrifugation. In case of getting gel of the specific ionic forces of 0,15 M and 0,3 M formed by addition of multivalent cations/anions from observations we can say that the ionic strength in the case of the method of preparation of gels does not matter.
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