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The effect of magnetic field and other selected stressors on physiology of bacterial cells
Mrázová, Kateřina ; Mravec, Filip (referee) ; Obruča, Stanislav (advisor)
This thesis deals with the effect of magnetic field and organic substances, namely benzene and p-nitrophenol, on cell of PHA producing bacteria Cupriavidus necator H16 and mutant strain Cupriavidus necator PHB4, which does not produce polyhydroxyalkanoates. Static magnetic field was generated by both permanent magnet and electromagnet. The effect of magnetic field on the growth of bacterial cells was studied using growth curves. It was found that cultivation in magnetic field and mineral medium mostly inhibits bacterial growth. Also the amount of polyhydroxyalkanoates was observed using FT-IR, flow cytometry and microscopy with fluorescent dye. Growth curves and flow cytometry were also used to study the influence of organic substances on bacterial cells. It was found that while benzene does not affect either C. necator H16 or C. necator PHB4, p-nitrophenol acts as the inhibitor of bacterial growth for both cultures. Finally the impact of p-nitrophenol on the accumulation of PHA was studied using gas chromatography.
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The effect of magnetic field and other selected stressors on physiology of bacterial cells
Mrázová, Kateřina ; Mravec, Filip (referee) ; Obruča, Stanislav (advisor)
This thesis deals with the effect of magnetic field and organic substances, namely benzene and p-nitrophenol, on cell of PHA producing bacteria Cupriavidus necator H16 and mutant strain Cupriavidus necator PHB4, which does not produce polyhydroxyalkanoates. Static magnetic field was generated by both permanent magnet and electromagnet. The effect of magnetic field on the growth of bacterial cells was studied using growth curves. It was found that cultivation in magnetic field and mineral medium mostly inhibits bacterial growth. Also the amount of polyhydroxyalkanoates was observed using FT-IR, flow cytometry and microscopy with fluorescent dye. Growth curves and flow cytometry were also used to study the influence of organic substances on bacterial cells. It was found that while benzene does not affect either C. necator H16 or C. necator PHB4, p-nitrophenol acts as the inhibitor of bacterial growth for both cultures. Finally the impact of p-nitrophenol on the accumulation of PHA was studied using gas chromatography.
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Study of bioremediation of some organic polutants by Cupravidus necator
Miléřová, Miluše ; Hurtová, Jana (referee) ; Obruča, Stanislav (advisor)
The aim of this work is the study of bioremediation of p-nitrophenol using bacteria Cupriavidus necator. The theoretical part contains a summary of organic pollutants and the bioremediation aproaches used to remove them from the environment. In the experimental part of this work we used bacteria Cupriavidus necator H16 and its mutant strain Cupriavidus necator H16/PHB-4 unable of PHB accumulation. The experiments were performed with different concetrations of p-nitrophenol and also under none-optimal conditions. Apart from concentration of p-nitrophenol, viability of the bacterial cultures was determined by flow cytometry. During cultivation in progress for sub-optimal conditions with a concentration of 50 mg•l-1 p-nitrophenol at 4°C using a flow cytometer seemed more resistant bacteria Cupriavidus necator H16. On the contrary strain Cupriavidus necator H16/PHB-4 was more resistant at 37 °C. The biodegradation assay was also performed in fermentor, during 51 hours lasting cultivation, bacterial culture degraded 65 % of p-nitrophenol and moreover decreased wavelenght of maximum in absorption spectra from 401 m to 384 nm was observed. The quantity of PHB was analyzed by gas chromatography with FID detector along with the p-nitrophenol determined by spectrophotometry, whose maximum content of PHB was achieved in 20 hour of cultivation
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