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Changes of microbial growth during use of face masks from different materials
Korvasová, Lucie ; Hoová, Julie (referee) ; Márová, Ivana (advisor)
Due to the current spread of Covid-19 disease, there are many types of respiratory protective equipment on the Czech market. However, due to the conditions that breath creates on the inside of the masks, they can be an ideal place for multiplication of microorganisms such as yeasts, moulds and especially bacteria. Since various protection masks differ in their production materials, bacteria colonization won’t always be the same. The subject of the thesis is a comparison of individual types of masks and respirators with regard to multiplication of microorganisms in their structure, which were tested using the contact stamp-form method on agar plates and in a liquid medium. Sterile environment was required during the work to avoid external contamination. Methods of imprinting on agar plates and the fact that turbidity and thus measurable absorbance increases with rising number of microorganisms were used to obtain the data. Result of the work was that face masks already contained some level of contamination from their production. As the best kind of face masks in terms of multiplication of microorganisms came out cotton, which prevented multiplying in the inoculated sphere. At the same time each growing culture was tested for viability, where it was determined how many viable cells each sample contained in comparison to a fully grown culture.
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Biological effects of substances isolated from Isoptera species
Dušková, Simona ; Hrstka, Miroslav (referee) ; Brázda, Václav (advisor)
This thesis was focused on monitoring the viability of eukaryotic and prokaryotic cells after exposure of termites-isolated chemicals. Recently, evidence of antibacterial and antifungal properties of these defense substances has grown, and they can find a wide range of uses not only in the pharmaceutical industry. In this work, three defensive substances from termites were studied: nerolidol, nitropentadecene and methylanthranilate. Their antibacterial effects, minimal inhibitory concentrations and minimal bactericidal concentrations against Escherichia coli STBL3 strain were monitored. Further, their cytotoxic effects on eukaryotic non-tumor (HEK293FT) and tumor cells (MCF7) as well as their effect on plasmid DNA were studied. Antibiotic ampicillin and cytostatic cisplatin were used as control substances for antibacterial and cytotoxic effects, respectively. In the case of the action of nerolidol, nitropentadecene and methylanthranilate on the STBL3 strain, antibacterial activity was not demonstrated. Cytotoxic effects were observed nerolidol and nitropentadecene. None of the examined substances modified the plasmid DNA.
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Influence of PHA accumulation on resistance of bacteria against selected antibacterial drugs
Hrabalová, Vendula ; Kučera, Dan (referee) ; Obruča, Stanislav (advisor)
The aim of this bachelor thesis was to study the effect of bactericidal drugs on bacteria from the genus C. necator H16 and its mutant genus PHB-4. The genus H16 shows ability to accumulate polyhydroxyalkanoates (PHA) in the form of granules while the genus PHB-4 lacks to show this ability. The theoretical part of the bachelor thesis is focused on the effect of antibiotics on bacteria in general and the determination of susceptibility of bacteria to antimicrobial substances. The effect of three specific antibiotics (nisine, streptomycin and penicillin) on both bacterial strains was tested in the experimental part. The viability of bacteria was determined by the spread plate method and flow cytometry. Agar diffusion test and broth microdilution test were used to test the susceptibility of bacteria. It was concluded that the accumulation of PHA decreases the tolerance of bacteria to antimicrobial substances because the genus C. necator H16 is more susceptible to streptomycin and penicillin then the strain C. necator PHB-4.
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Investigation of yeast properties during the beer fermentation
Kociánová, Lenka ; Vítová, Eva (referee) ; Omelková, Jiřina (advisor)
In this diploma thesis, the properities of brewery’s yeasts during the operation beer fermentation in the selected brewery and dependences of diferent agents and their influence on viability and vitality of the yeasts were studied. Other observed properities were physiological state, pH, temperature, a value of soft and coarse sludges, a value of dissolved oxygen in wort, the level of wort’s fermentation. It were collected the samples of fermenting wort and washing yeasts for determination. The used yeasts were observed from the first time until thein last used (generally 4 times). pH, temperature, apparent fermenting and total numer of yeast cells were measured in the collected samples. The used yeasts were washed before every other application and vitality was determined. The number of death cells were observed by this method. The number of death cells never fell bellow 5 %. The value of dissolved oxygen in wort is also the important agent for the growth of yeasts. The touchs with low number of oxygen showed that the time for fermentation had to be longer (by about 3 or 4 days more). The touchs with higher number of sludges showed that the sludges haven’t any influence on the yeasts and the procces of fermentation. Confirm the accuracy of the repeated used of the yeasts was the object of this thesis.
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Involvement of polyhydroxyalkanoates into stress response of bacteria
Kučera, Dan ; Skoumalová, Petra (referee) ; Obruča, Stanislav (advisor)
The aim of this work was to study the involvement of polyhydroxyalkanoates (PHA) into stress response of bacteria. The theoretical part of the thesis deals with the possibility of establishing the viability of microorganisms using modern techniques, in particular flow cytometry. Furthermore, the research focused on selected stress factors and PHA involvement in stress response was described. In the experimental part of the work the stress response with regard to the ability to accumulate PHA was assessed. Bacteria Cupravidus necator was used for the experiment. Its ability to accumulate PHA at a later stage of growth increased resistance to ethanol, high temperature and freezing. Conversely, the PHA-producing strain showed lower resistance to the action of inorganic acids and bases. This may be caused by different morphology of PHA-producing cells. One of partial objectives was also to study the possibilities of staining of living cells accumulating PHA using Nile red. The research proved that the dye penetrates into living cells at elevated temperature of 40-45°C. This temperature is not lethal to the cells and the intensity of staining is sufficient to distinguish PHA-producing cells using flow cytometry; that can be applied in the selection of industrial PHA producers.
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Utilization of physicochemical and spectroscopic techniques in study of stress-response of cyanobacteria
Skoryk, Maksym ; Šedrlová, Zuzana (referee) ; Sedláček, Petr (advisor)
Tato bakalářská práce je soustředěná na zkoumaní cyanobakterií, vystavených hyper a hyposmotickým stresům. Na základě literární rešerše byly navžené vhodné analytické metody určené ke studiu dvou modelových organismu - Synechocystis sp. PCC 6803 a Synechocystis sp. salina Wislouch CCALA 192. Celkem čtyři metody byly použité k charakterizaci osmoticky zatížených bakterií. Průtoková cytometrie byla použita k vyhodnocení viability. Fluorescenční sonda SYTOX Blue poskytla důvěryhodnou informaci ohledně viability bakterií. Propidium jodid naopak poskytl nezřetelnou informaci. Optické vlastnosti cyanobakterií byly prozkoumané pomoci UV-VIS absorpčních a turbidimetrických měření. Termogravimetrická analýza byla použita pro mapování změn obsahu vody v osmoticky stresovaných buňkách. Tato metoda ukazala. že PHB-positivní Synechocystis sp. PCC 6803 jsou pravděpodobně vice odolné vůči hyperosmotickým stresům než PHB-negativní. Plynová chromatografie byla použita ke kvantifikaci vnitrobuněčného PHB, který činil přibližně 1-2 % suché hmoty PHB-positivních buněk.
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Addition of probiotics and algae extracts to baby foods
Liová, Alexandra ; Szotkowski, Martin (referee) ; Němcová, Andrea (advisor)
This bachelor thesis deals with the selection of a suitable combination of probiotic culture with algae extracts as an addition to the baby formula and the application of the optimal composition of baby formula. Arame, wakame, hijiki and kombu seaweeds were selected for these purposes. The theoretical part is focused on the proper nutrition of children, their deficiencies and possible diseases. Subsequently, it deals with the characterization of probiotic cultures and their importance in the child's nutrition. Last but not least, the theoretical part characterizes the individual seaweeds, their nutritional composition and also their importance in the child's nutrition. In the experimental part, samples of selected algae were first analyzed in terms of saccharides, insoluble fiber content, fructooligosaccharides and -glucans or pigment content. A sample of inulin, a commonly used prebiotic in probiotic products, was used as a reference component. An important analysis of this experimental part was to determine the effect of algal extracts on the viability and growth of probiotic bacteria. Subsequently, a model digestion of a mixture of probiotics and algal extracts was performed, and the condition of the probiotic cells was evaluated during digestion and after digestion by measuring turbidity and flow cytometry. Finally, not only the optimal combination of algae extract and probiotic culture was proposed, but also the possibility of improving the long-term viability of probiotic cells in combination with algal extracts.
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Analysis of bacrerial cells employing flow cytometry and flurescence microscopy
Müllerová, Lucie ; Mravec, Filip (referee) ; Obruča, Stanislav (advisor)
This thesis focuses on fluorescent analysis of viability and PHA content in bacterial cultures, the main methods of investigation were flow cytometry and fluorescent microscopy. In order to determine viability of C. necator H16, several viability probes were tested, nevertheless, only BacLightTM kit and propidium iodide can be used to estimate portion of viable and live bacterial cell in samples. Further, Acridine orange was used to monitor physiological state of bacterial culture and two hydrophobic probes, Nile Red and BODIPY 493/503, were used to investigate PHA content in bacterial cells. Application of BODIPY 493/503 seems to be promising since this probe does not require permeabilization of bacteria cells and it can be used along with propidium iodide. Furthermore, several fluorophores were tested in the microscopic part. In was found that concentrations used in cytometric analyses were too high for microscopic use. Emission from the SYTO9 fluorophore is seen mainly in the green channel but because of the high concentration some emission was visible in the red channel. Cells stained with BODIPY 493/503 had very high fluorescence intensities when the stain concentration was 10 . At the same time, negative amplitudes of fluorescence were measured in both strains of C. necator, but in case of C. necator H16 that amplitude was much more pronounced. In this strain surprising high concentration of BODIPY stain was observed on the surface of PHB granules. Anisotropy of the fluorophore was nearing 0 which is very surprising.
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Study on PHa biosynthesis by cyanobacteria
Drinka, Jakub ; Kouřilová, Xenie (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis concerns with the effect of selected environmental stresses towards the viability of cyanobacterial species Synechocystis sp. PCC 6803 and Synechocystis salina CCALA 192. Both strains were studied via flow cytometry using the appropriate fluorochromes while also observing the applicability of these stains and precision of this method in the analysis of cyanobacterial cultures. In spite of the optimization being carried out, fluorescein diacetate was not suitable for the analysis of these cells because of their autofluorescence interfere with the fluorochrome emissions. Therefore, SYTOXTM Blue Dead Cell stain was used for the further experiments. A cryoprotective effect of polyhydroxybutyrate was observed during the freezing-thawing cycles. On the other hand, the culture rich in PHB seemed to be less resistant towards the oxidative stress induced by the hydrogen peroxide, probably justifiable by the state of chlorosis. Furthermore, this thesis deals with the increase/decrease in biomass concentration and intracellular PHB pool as a response to the external carbon source addition, analysed by the gas chromatography paired with FID detection. The most intesive cell growth in Synechocystis sp. PCC 6803 was detected in the presence of sodium acetate combined with gamma-butyrolactone while the highest PHB content in the medium supplied with acetate and 1,4-butanediol. Nevertheless, Synechocystis salina CCALA 192 showed markedly higher polyhydroxybutyrate accumulation under both photoautotrophic and mixotrophic conditions, the only non-suitable substrate was gamma-butyrolactone.
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