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Physicochemical and structural analysis for characterization of native and modified humic acids
Solanský, Pavel ; Sovová, Šárka (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis is focused on structural and physicochemical characterization of native and methylated humic acid. These samples of humic acids, which were isolated from oxidized brown coal Leonardite, were characterized by thermal and spectrometric methods. The following analytical techniques were selected to determine the structural and physico-chemical changes between native and methylated humic acid: thermogravimetry (TGA), elemental analysis (EA), molecular absorption spectroscopy (UV/Vis), Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy and last but not least nuclear magnetic resonance (13C NMR). The aim of this bachelor thesis was to find the differences in the structure of selected humic acids and also to verify the suitability of the techniques, which were used to characterize these biocolloid substances.
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Sorption of charged organic compounds on humic acids
Krist, Tomáš ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
Bachelor thesis deals with a sorption properties and physical-chemical characterization of humic acids before and after the adsorption. Sorption experiments with a methylene blue and a rhodamin 6G were performed. Adsorption isotherms were obtain via UV/VIS spectrometry. The Langmuir isotherm was used to evaluate the experimental data. Standard of HA isolated from Leonardite was characterized by an elemental and thermogravimetric analysis, by a Fourier-transform infrared spectroscopy, a surface area analysis and also by a potentiometric titration.
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Isolation and fractionation methods for determination of humic substances content in Leonardite
Lišková, Kateřina ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
The main aim of this thesis was to isolate humic substances (HA and FA) from the natural sample of Leonardite, to characterize their structure and physical and chemical properties. Among other things, the humic acid standard supplied by IHSS, isolated from Leonardite, originally from Dakota, USA, was also studied. The following thermal and spectrometric methods were used to characterize the samples of isolated humic substances: thermogravimetric analysis (TGA), elemental analysis (EA), ultraviolet-visible spectrometry (UV / Vis) and infrared spectrometry with Fourier transformation (FTIR). The atomic ratios were determined from the results of the elemental analysis. Absorption coefficients were calculated from the measured UV/Vis spectra and were used for the physicochemical characterization of these biocolloid compounds. The measured infrared spectra were used to identify the individual functional groups.
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Utilization of Raman spectroscopy and Raman tweezers for analysis and isolation of PHA producing bacteria
Beránková, Barbora ; Enev, Vojtěch (referee) ; Obruča, Stanislav (advisor)
This diploma thesis deals with the study of the utilization of Raman spectroscopy and Raman tweezers for analysis and isolation of polyhydroxyalkanoates (PHA) producing bacteria. Using gas chromatography with FID detection, we determined the polyhydroxybutyrate (P(3HB)) content of the PHA biomass of bacterial strains Burkholderia cepacia, Halomonas halophila, Cupriavidus necator H16 and its mutant strain Cupriavidus necator H16/PHB-4 and Lactobacillus delbrueckii, which is not a producer of polyhydroxyalkanoates but this bactrea was selected as representative of Gram-positive bacteria. Subsequently, thanks to Raman microspectroscopy, Raman tweezers and FT-IR spectrometer in combination with Raman FT-module, we were able to confirm or disprove the presence of P(3HB) in bacteria. Furthermore, the thesis describes Cupriavidus necator H16, which is a model organism for the production of P(3HB), and his mutant strain Cupriavidus necator H16/PHB-4. The bacterial strain Cupriavidus necator H16 was cultivated in a production mineral medium of various nitrogen contents, while cultivation was also carried out in liquid Nutrient Broth. By this cultivation we were able to reach various P(3HB) content in bacterial biomass, the spectra were subsequently compared with the spectrum of the bacterial strain Cupriavidus necator H16/PHB-4. Raman spectroscopy is well used to characterize the composition of individual bacterial cells, is a fast, versatile, and virtually non-invasive tool for studying cells.
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Interactions of hormones and drugs with soil organic matter
Krajňáková, Soňa ; Enev, Vojtěch (referee) ; Klučáková, Martina (advisor)
This thesis is focused on the problem of interaction of hormones and drugs with a soil organic matter. The most commonly occurring drugs are described, as well as their features, behaviour and possible factors influencing this behaviour. These substances are frequently transported to the soil through a sewage treatment plant, as the cleaning process of wastewater is not effective enough to ensure complete removal of these substances. Once in the soil, the life of organisms in this environment can be negatively influenced. The soil used in experiments was not contaminated with any of these substances as it was used as a matrix for sorption and desorption. Two experiments were conducted using Ibuprofen, where its sorption and desorption on the soil was observed. The intention was to ensure detection of changes which occurred in the concentration of Ibuprofen after concluding these processes. Liquid chromatography method with mass spectrometric detection was used for a final analysis.
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Raman spectroscopy as a tool for analysis of microbial cells
Pokorný, Petr ; Enev, Vojtěch (referee) ; Samek, Ota (advisor)
This bachelor thesis is focused on the use of Raman spectroscopy for analysis of ectoine and hydroxyectoine presence in bacterial strain Halomonas elongata. Theoretical part compile characteristics of extremophiles with closer look on halophilic organisms and one of their main osmolytes, ectoines. Following by description of Raman spectroscopy method and its uses. Experimental part deals with cultivation of bacteria on different combinations of substrate and salt concentration in order to reach optimal production of PHA and for achieving the highest possible yield of biomass to be analysed by Raman spektroskopy. As the best substrate for PHA production turned out to be glukose along with salt concentration 30 g/l NaCl, where percentage representation of PHB makes 30,5229 %. As an ideal substrate for the highest yield of biomass proved to be sacharose. Bacteria that grew on sacharose with three different salt concentrations, 40, 70 and 100 g/l NaCl was measured along with Halomonas salina and Halomonas organivorans for comparison. Raman spectroscopy unfortunately turned out to be inadequate for measurement of this type of sample, thus we were not able to measure ectoine of hydroxyectoine presence in cells.
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Analytical methods for determination of polyhydroxyalcanoates content in bacterial cells
Černayová, Diana ; Enev, Vojtěch (referee) ; Sedláček, Petr (advisor)
This bachelor thesis deals with methods that are used for determination of polyhydroxyalkanoates (PHA) in cells of bacteria Cupriavidus necator H16. To the applied methods belong Fourier transform infrared spectroscopy, Raman spectoscopy, turbidimetry and thermal analysis (thermogravimetric analysis and differential scanning calorimetry). The results of each method were compared to amount of PHA determinated by gas chromatography. Fourier transform infrared spectroscopy and Raman spectroscopy revealed a linear relation between ratio of characteristic peaks and amount of PHA. FTIR enabled to determine not only the quantitative amount of PHA, but the quality of the sample (cristallinity, amorphous state) as well. Another method was turbidimetry, which has shown correlation between dispersion of UV-VIS light to amount of PHA in bacterial cells. Thermogravimetric analysis was the most effective technique for determination of PHA. The dependence of weight loss of PHA on its content (found by gas chromatography) was determined with the highest accuracy to gas chromatography. Tha last method- DSC was not alternative replacement for quantitative PHA determination. However, DSC indicated crystalline and amorphous state of the polymer.
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Stability of soil organic matter and humic substances
Nováková, Šárka ; Enev, Vojtěch (referee) ; Klučáková, Martina (advisor)
This diploma thesis is focused on changes of stability in organic matter by extraction in different agents. Two soils of a different type and isolated humic acids were used for stability determination. Extraction agents were selected usually used for soil metal extraction, and a changes in the structure of the organic matter was observed. Samples were characterized using FTIR analysis and elemental analysis, the extracts were measured by UV-VIS spectroscopy, absorption ratios E2/E3, E4/E6 were discovered, dynamic light scattering were determined for particle size distributions. Next part of the thesis was the assessment of the change of thermal stability using thermogravimetric analysis and differential scanning calorimetry, degradation temperatures of the extracted samples were discovered and compared with the original samples.
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Characterization of humic substances isolated from natural waste treated by vermicomposting process
Marková, Kamila ; Doskočil, Leoš (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis deals with the study of humic substances isolated from vermicompost natural waste through spectrometric methods. The aim of this thesis is to study physicochemical properties of the humic substances through modern instrumental techniques such as molecular absorption spectroscopy in the ultraviolet and visible regions of electromagnetic radiation (UV/Vis), infrared spectroscopy with Fourier transformationn (FTIR), elemental analysis (EA), thermogravimetric analysis (TGA) and inductively coupled plasma emission (ICP OES). A research focused on basic information about the humic substances was developed in the theoretical part. A description about their distribution or structure was made and also their utilization in medicine, industry or ecology. Then, methods, which are used for study of the humic substances, were described as well. An essential part of the thesis was isolation of humic and fulvic acid from the vermicompost natural waste. Absorption coefficients were calculated from the measured UV/VIS spectrum which served to following characterization of HK and FK. FTIR spectrum was used to determination of functional groups of studied HL. An area of biogenic elements was specified using the elementary analysis. Total amount of studied trace elements was determined with with the help of ICP-OES.
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Experimental study on the release of active ingredients from gel matrices
Volhinava, Anastasiya ; Enev, Vojtěch (referee) ; Sedláček, Petr (advisor)
This thesis deals with the characterization of hydrogels containing humic substances and salicylic acid. Experimental study of the transport of active substances was performed from the gel matrix over the skin and synthetic membranes. During this work was writing literature review focused on the use of gels with humic substances in cosmetic, medical and pharmaceutical industries. The model humic hydrogels was prepared with salicylic acid and their characterization by basic methods of material analysis. These basic methods were and visual assessment of consistency during the preparation and rheology. The study of the release of active and humic substances was performed due to the vertical diffusion cells. The amount of released humic substance was characterized by UV-VIS method and the amount of released salicylic acid from gel matrix was determined by HPLC.
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