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The Influence of Biochar Application on the Microbiological Characteristics of Soil
Štorková, Natálie ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
This diploma thesis is focused on the effect of Pflazenkohle biochar application into the soil and its corresponding microbial characteristics. Along with microbial characteristics (microbial functional diversity, microbial and enzymatic activity), the effect of biochar on soil physicochemical properties (pH, organic matter content, organic C and N content) and plant growth (height, above and below ground dry weight) was also assessed in this thesis. Two types of soils with low organic matter content (sandy arid soils and arenaceous chernozem) were used for the experiments. These soils were obtained after two years of cultivation with biochar at application doses 0 and 20 g-kg-1, maize (Zea mays) was selected as the model plant. The results of the cultivation experiment showed that Pflanzenkohle biochar has the potential to affect soil microbial properties, soil physicochemical properties and also plant growth, but its detectable effects on microbial characteristics of soil were limited. This was probably caused by the inappropriate biochar application form and also by the selection of soil type used for cultivation experiment. To be able to further study the effect of biochar on the soil microbial properties we considered, it would be necessary to modify the setting of cultivation experiments in the way to pronounce the statistically significant differences.
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Interactions of pharmaceuticals with fulvic acids – calorimetric study
Papko, Nadezhda ; Sedláček, Petr (referee) ; Klučáková, Martina (advisor)
Tato diplomová práce se zaměřuje na studium interakcí mezi půdní organickou hmotou a vybranými léky pomocí izotermické titrační kalorimetrie. V rámci experimentu byly použity tři fulvinové kyseliny a léky: ibuprofen, diclofenac a sulfapyridine. Vybrané léky a fulvinové kyseliny byly rozpouštěné v roztocích NaCl a MgCl2, jelikož kovové ionty jsou přítomny v organickém materiálu půdy. Mobilita léčiv závisí na sorpci, což je interakce mezi léčivy a půdními částicemi. Faktory ovlivňující sorpční chování zahrnují vlastnosti léčiv, půdy a enviromentální podmínky. Během bakalářské práce podražilo optimalizovat metodu ITC pro daný studiu, což usnadnilo experimentální práce a zlepšilo vyhodnocení dat. Pomocí metody byli stanovené tepelné efekty (naměřené a porovnané) interakcí mezi fulvinovými kyselinami a léky.
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Development and experimental evaluation of bioactivity of the next-generation bioinnoculants
Súkeník, Martin ; Pekař, Miloslav (referee) ; Sedláček, Petr (advisor)
This diploma thesis aimed to characterize specific mechanisms of biological activity in plant growth-promoting rhizobacteria (PGPR) commonly found in the rhizosphere of plants and to study the effects of liquid and gel application of PGPR bioinoculants on plants in a controlled environment. An original concept of self-encapsulation via cross-linking of alginate directly produced during their culturing was proposed for the preparation of gel bioinoculants based on these PGPRs. To validate the efficacy of this concept, all selected strains had to be subjected to gelation experiments with the crosslinking agent CaCl2 2 wt. % under alginate gel formation. Three specific strains of Azotobacter vinelandii DSM 87, DSM 720 and CCM 289 were selected for the preparation and characterization of the bioinoculants. The material properties of the formed gels were characterized by oscillatory rheometry (amplitude test). All strains were subjected to gravimetric determination of alginate and biomass concentrations. Flow cytometry with fluorescent probe PI, DAPI and SYTOX™ Green was used to verify cell viability immediately after culturing. Furthermore, the drying of gels was performed using a lyophilizer, where the lyophilized gel was used in swelling experiments followed by drying. To verify the biological activity of the bioinoculants, the ability of all strains to dissolve and utilize phosphate from the agar medium was qualitatively verified. Furthermore, the production of indole-3-acetic acid was spectrophotometrically verified for all strains. The production of siderophores was also verified qualitatively and quantitatively. Cultivation pilot experiments on the lettuce (Lactuca sativa) plant were performed with the addition of both liquid and gel carrier PGPR compositions; as a negative control, the plant was left without the addition of carrier PGPR composition. The results from the pilot growth experiment showed a positive growth effect of both gel and liquid PGPR composition on the plants. At the end of the growing experiment, higher leaf and root system lengths were recorded after the application of both forms of PGPR to the soil, specifically, the average leaf length with the addition of gel carrier PGPR composition was 4.3±1.0 cm and 4.3±1.2 cm for the gel carrier PGPR composition, and the average root system length was 18.3±5.2 cm and 17.4±6.0 cm, respectively. The dry weight per plant grown with the addition of liquid and gel PGPR was the same 0.19±0.07 g. The highest content of chlorophyll a, chlorophyll b and carotenoids in the leaves was spectrophotometrically detected in plants grown with the addition of liquid PGPR composition, specifically chlorophyll a was found to be 6±1 µg/ml, chlorophyll b 7±2 µg/ml and carotenoids 3.6±0.5 µg/ml. The diversity of soil microbiomes collected from the soil without the addition of PGPR composition, with the addition of liquid PGPR composition and with the addition of gel PGPR composition was analysed using BIOLOG EcoPlate™ plates. The diversity of the microbiome was evaluated using the average well colour development, i.e., the AWCD parameter, and the Shannon diversity index, H'. The highest utilization of the widest number of carbon sources on the plate was recorded for the soil microbiome with the addition of the gel PGPR composition. The aforementioned soil microbiome also showed the highest value of the H' index.
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Study on metabolism of polyhydroxyalkanoates in selected thermophilic bacteria
Reinohová, Nikola ; Sedláček, Petr (referee) ; Pernicová, Iva (advisor)
This thesis is focused on adaptive evolutionary engineering in the thermophilic bacterium Schlegelella thermodepolymerans M15344. The theoretical part deals with extremophilic microorganisms, biotechnological applications as well as polyhydroxyalkanoates and evolutionary engineering. In this work, adaptation of this microorganism to 40 °C and 60 °C was carried out using glucose and xylose substrates. Furthermore, repeated-batch cultivation at 50 °C on glucose and xylose was performed. In these experiments, the concentration of PHA produced in the biomass was determined by gas chromatography, and the concentration of residual sugars in the medium was determined by a method using DNS. Production of polyhydroxyalkanoates in the adapted strains from each experiment was compared with the non-adapted strain. Subsequently, the PHA produced by individual bacteria was studied using the SEC-MALS method, where the effect of adaptation on molecular weight was observed. The highest producing bacteria was adapted to 40 °C and the substrate was glucose. In this case, the biomass value was 6,74 g/l with a PHA percentage of 56.5 wt%. The bacteria was also adapted to 60 °C where it was able to grow and produce unlike the original bacteria.
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Program-controlled freeze drying for the preparation of the delivery system based on hyaluronan and real drugs
Řihák, Marek ; Sedláček, Petr (referee) ; Enev, Vojtěch (advisor)
The aim of this thesis was to prepare native hyaluronan-based carrier systems using the lyophilisation as a suitable method to ensure an interaction between certain drugs and the polymeric structure which would lead to an increased solubility of hydrophobic drugs. For the preparation of such a system the tert-butyl alcohol was used as a co-solvent with the ability to support hydrophobic effect between the drug and a hydrophobic domain of hyaluronan. Since all polar domains of hyaluronan are located in the equatorial position, the axial position is occupied by hydrogens and therefore the molecule gains the amphiphilic character. Previous studies have confirmed that freeze-drying is a useful method for a carrier system preparation. However, this study focuses on the preparation of such systems with samples of real drugs, which were previously replaced by fluorescence sondes. Since all drug samples have good fluorescence characteristics, the fluorescence spectroscopy was used as the main method to determine the success of the preparation. Other methods included a thermogravimetric analysis and the infrared spectroscopy with Fourier transformation. All the mentioned methods have confirmed that lyophilisation is a useful method for the preparation of the carrier systems with real drugs. Great results have been achieved in the terms of the solubility of freeze-dried systems. In the last step, the co-solvent residues were determined by head-space solid phase microextraction. This method also provided some valuable information and confirmed that tert-butyl alcohol could be found in the lyophilised systems only on very low levels.
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Humic substances as modifiers of the transdermal absorption of active phasrmaceutical ingredients
Blahuš, Petr ; Klučáková, Martina (referee) ; Sedláček, Petr (advisor)
This thesis deals with the influence of humic substances on the transdermal penetration of the analgesic drug ibuprofen. Analgesics in the form of oral administration have major side effects. Thanks to topical preparations, side effects could be reduced and also bring a number of other benefits. The problem in the development of a transdermal form of the drug is the very effective barrier capacity of the human skin. Therefore, a lot of research is focused on the search for various accelerators that can improve its properties due to interaction with the drug. In the future, such substances could also include humic acids, which have a long tradition of use in a number of therapeutic approaches, and recently examples of their use in human medicine are increasingly appearing. The research was focused on the diffusive transport of sodium ibuprofen and its acidic counterpart. Franz diffusion cells were used to simulate the real environment, and skin isolated from pig ears was used as a membrane. Using UV-VIS spectrophotometry and HPLC, the samples were analyzed. Several values were calculated from the measured data, such as the effective diffusion coefficient, which were then compared and statistically checked. The result of this thesis is data that show the positive effect of humic substances on the transport of drugs through the skin membrane.
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Involvement of vibrational spectroscopy in the study on interactions of natural organic matter with model environmental pollutants.
Stehlíková, Kristína ; Enev, Vojtěch (referee) ; Sedláček, Petr (advisor)
The main objective of this diploma thesis was to verify the potential of using advanced infrared spectra processing techniques – specifically the principal component analysis (PCA) – in order to monitor the interaction of natural organic matter with organic pollutants. Natural organic matter was represented by standard IHSS Leonardite humic acid, while the aromatic dyes methylene blue and Rhodamine 6G and the aliphatic substance Septonex were chosen as representatives of organic ions. Their interactions were monitored using Fourier-transform infrared spectroscopy, the use of which for this purpose was verified in my bachelor's thesis. Principal component analysis was finally applied to the obtained infrared spectra of the formed complexes and prepared blank samples, which helped to reveal spectral changes at first glance unrecognizable in the spectra themselves. It was found out that the most likely mechanism of humic acid interaction with aromatic pollutants is a - interaction, while the electrostatic nature of the interaction is assumed for the binding of aliphatic substances.
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Involvement of various gelation strategies in development of next-generation bioinnoculants
Krýslová, Jana ; Smilek, Jiří (referee) ; Sedláček, Petr (advisor)
This diploma thesis deals with the investigation cross-linking approaches of the bacterium Azotobacter vinelandii, which belongs to the PGPR group and is capable of producing alginate extracellularly. This crosslinking concept represents a novel approach to development of bioinoculants based on the PGPR. The first part is dedicated to investigating the effect of oxygen on the gelation of bacterial cultures itself. Experimentally, it was found that bacterial cultures in a total volume of 50 and 100 ml in 250 ml Erlenmeyer flasks showed spontaneous gelation already during the cultivation process, while the formed gels were measured rheometrically and showed values of const. complex modulus 0,026 kPa and 0,030 kPa. With a bacterial culture in a total volume of 150 ml, spontaneous cross-linking itself did not occur. In addition to gelation testing, the content of PHB and extracellular alginate and its molecular weight were determined in the bacterial cultures using size exclusion chromatography with multi-angle light scattering (SEC-MALS) and the mechanical properties of the resulting gels using rheometry. Cross-linking of bacterial cultures took place mainly with the use of CaCl2 as a cross-linking agent, but various alternative methods of gelation were tested as well (by means of polyvalent ions, weak organic acids, precipitants such as DMSO, emulsion gelation). The effect of glucono-D-lactone (GDL) as a gelling agent based on a slow release of crosslinking ions from their insoluble form was also tested. The strongest gels were formed by the addition of polyvalent ions (they ranged in the value of the complex modulus of 10 kPa, in the case of the use of weak acids and DMSO, the gels ranged in the value of the complex modules in the range of 1 to 10 kPa. The addition of GDL did not create gels immediately, but delayed, and gelation was observed in time.The formed gel ranged in value up to 1 kPa.
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Wartime economic headquarters in Cisleithania (1914-1918)
Sedláček, Petr ; Kubů, Eduard (advisor) ; Štolleová, Barbora (referee) ; Jemelka, Martin (referee)
The dissertation deals with the topic of Wartime Economic Headquarters in the time span of the First World War in Cisleithania; these organisations are understood primarily as institutions authorized with the administration of goods and foodstuffs in short supply. Firstly, the thesis evaluates and defines the position of the Wartime Economic Headquarters in the system of the Cisleitanian war economy, offers their classification based on their roles and forms and it offers their overview. In the three individual studies the thesis deals in detail with the chosen Wartime Economic Headquarters - The Wartime Grain Agency, The Central Sugar Agency, and the organizations active in the field of the cotton industry - The Central Cotton Agency, and The Wartime Union of Cotton Industry. Based on a thorough analysis of wartime legislation, the thesis specifies the tasks and role of each closely analyzed organization in the framework of governmental regulation. It follows the chosen organizational forms of the respective organizations, including the persons in charge and it evaluates the profitability of those organizations. Above all, the thesis deals with the ways, in which the said organisations took part in performing of the state regulations of the individual branches. Moreover, the thesis puts a closer...
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Transport Properties of Gellan Hydrogels
Sokolínský, Jan ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
This bachelor thesis deals with the characterization of mechanical and transport properties of gellan based hydrogel systems. As gellan gum is a biopolymer, hydrogels based on this biopolymer are suitable candidates for use in the pharmaceutical industry and medical applications. The characterization of mechanical properties was realized by rheological analysis and by drying scales, transport properties were characterized by diffusion experiments in combination with the detection using UV-VIS spectrometry. The result of this work is a comparation and commentary of the measured data, in order to provide an overview of the properties of physical gellan gum hydrogels. It was found out that by changing the concentration of the biopolymer and by a suitable selection of the dispersion medium, transport, and mechanical properties of the physical gellan gum hydrogels can be modified.
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