|
|
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.
|
|
|
Preparation and characterization of magnetic nanoparticles modified by surfactants
Solnička, Ondřej ; Másilko, Jiří (referee) ; Enev, Vojtěch (advisor)
Theme of this bachelors thesis was preparation and characterization of iron(II, III) oxide nanoparticles. Those nanoparticles were modified by surfactants. The surfactants which were used for modifiation were CTAB, TTAB and Septonex. Prepared and modified nanoparticles were taken for characterization by using methods of elemental analysis, thermogravimetry, dynamic light scattering and transmission electron microscopy (TEM). Results from each measurement shows that nanoparticles modified by CTAB had on average 85.9 nm in diameter, TTAB size was on average 108.3 nm and the last nanoparticles with Septonex had 246.6 nm in diameter on average. Prepared modified nanoparticles except the Septonex ones were stable enough to not aggregate. Septonex modified nanoparticles had greater tendenty to aggregate.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
Decomposition and stability of organic matter in soil
Tabaková, Eva ; Enev, Vojtěch (referee) ; Klučáková, Martina (advisor)
In the soil, the plant material is decomposed by several factors. In the process, one part of the carbon returns to the atmosphere as carbon dioxide, whereas another part is stabilised in the soil. The aim of this study is decomposition and stability of organic matter in soil using a simple and innovative TBI method. Through this method, we examined the weight change after the incubation period of 90 days, where biomass of green tea was degraded in cambodia soil. Tea bags have provided us with valuable information on the decomposition and amount of carbon in the soil, because the biomass itself is of organic origin. This information is based on the fact that the soil and the decomposition processes have a direct impact on the change in climatic conditions. Thanks to further analytical methods, elemental analysis, thermogravimetric analysis and infrared spectroscopy with Furier transformation, was found indispensable information about tea composition.
|
|
|
Study and characterization of organic substances in a biochar sample
Vojáčková, Beáta ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis characterizes biochar from a physico-chemical point of view. The theoretical part deals with biochar as a soil conditioner, its properties, use, production, and last but not least, effect of its sorroundings. For better characterization of organic and inorganic matter a phosphate buffer was used. This buffer ensures their specific extraction due to a neutral pH. The second path is to use rainwater, which simulates the condition of the soil environment. In the experimental part are discussed both; purified buffer-extracted samples and rainwater samples, which were studied by thermogravimetric analysis (TGA), elemental analysis (EA) and by infrared spectroscopy with Fouier transform (FTIR-ATR). Conductivity and pH were also measured. Moisture and ash content, which represent the inorganic non-combustible fraction, were determined using thermogravimetry. The extraction yields were converted to ashless wt. % based on these values. Results of EA provided us with information on the content of biogenic elements and basic physico-chemical characteristics of biochar. In contrast, the FTIR method defined the presence of individual functional groups and specific constitutive units, which are present in the extracts. This information allows us to better understand the environmental impact of biochar on the soil ecosystem.
|
|
|
Spectrometric Methods for Research of Humic Substances
Enev, Vojtěch ; Maršálek, Roman (referee) ; Sýkorová, Ivana (referee) ; Klučáková, Martina (advisor)
The main aim of doctoral thesis is the study on physicochemical properties of humic substances (HS) by modern instrumental techniques. The subject of the study were HS isolated from South Moravian lignite, South Bohemian peat, forest soil Humic Podzol and finally extract from brown sea algae Ascophyllum nodosum. With respect on determination of structure and reactivity of these unique “biocolloids”, standard samples (Leonardite HA, Elliott Soil HS and Pahokee Peat HS) were also studied. These samples were obtained from International Humic Substances Society (IHSS). All mentioned substances were characterized by elemental analysis (EA), molecular absorption spectroscopy in ultraviolet and visible region (UV/Vis), infrared spectroscopy with Fourier transformation (FTIR), nuclear magnetic resonance spectroscopy of carbon isotope 13C (LS 13C NMR), steady-state and time resolved fluorescence spectroscopy. Obtained fluorescence, UV/Vis and 13C NMR spectra were used for calculation of fluorescence and absorption indexes, values of specific absorbance and structural parameters respectively, which were used for fundamental characterization of these “biocolloidal” compounds. Infrared spectroscopy with Fourier transformation was utilized for the identification of functional groups and structural units of HS. Evaluation of infrared spectra is quiet complicated by overlapping of absorption bands especially in fingerprint region. This problem was overcome by Fourier self-deconvolution (FSD). Steady-state fluorescence spectroscopy was used for deeper characterization of HS with respect to origin, structural units, amount of substituents with electron-donor and electron-acceptor effects, content of reactive functional groups, “molecular” heterogeneity, the degree of humification, etc. Parameters of complexation of samples Elliott Soil with heavy metal ions (Cu2+, Pb2+ and Hg2+) were obtained by using modified Stern-Volmer equation. These ions were chosen purposefully, because the interaction of HS with these ions is one of the fundamental criteria for the assessment of the reactivity of HS. Key part of the whole doctoral thesis is time-resolved fluorescence spectroscopy. It is able to determine the origin of emission of HS by method Time-Resolved Area Normalized Emission Spectra (TRANES). The viscosity of micro medium about excited fluorophores of HS was determined by Time-Resolved Emission Spectra (TRES).
|
|
|
Carbon nanoparticles from South Moravian lignite
Drozdová, Miroslava ; Enev, Vojtěch (referee) ; Pekař, Miloslav (advisor)
This bachelor thesis deals with the issue of isolation of carbon nanoparticles from lignite, which seems to be their cheap source. The aim of this work is to elaborate a research on the use of coal matrices as a source of carbon nanoparticles and also to design and perform further experiments testing the usability of South Moravian lignite. Based on the literature search, a simple mechanochemical procedure was proposed to obtain carbon nanoparticles from lignite. The lignite was mechanically stressed by the ultrasonic disintegrator with simultaneous action of water or hydrogen peroxide. Lignite has been able to isolate particles fluorescing in the blue visible light, but the process will need to be further modified. However, South Moravian lignite could be a source of carbon nanoparticles.
|
|
|
Influence of compost application on properties of soil humic substances
Enev, Vojtěch ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
The aim of this diploma thesis is to study to the influence of compost addition to soil humic substances extracted from blackland luvicsol. Humic substances extracted from soil and from compost were characterized by titration with potentiometrical and conductival indication, UV-VIS, FT-IR and 3D EEM fluorescential spectroscopy. Compost in amount of 124, 239 and 478 t/ha was applicated and manured into dept of 150 mm at blackland luvicsol. The main aim of thesis was the appraisal of compost influence into fluorescent attributes of soil HS and localization of fluorescent peaks at excitation emission spectrums. Next part of diploma thesis was focused on the study of spectroscopic attributes of soil HS and compost by UV-VIS and infrared spectroscopy with Fourier transformation. Humic substances were characterized by humifical index E4/E6 and transmissional vibratile spectrums. The last aim of diploma thesis were the characterization of soil HS extracts and compost by acidimetral titration. For each sample was calculated value of H+ ionts amount of substance from measured titrational curves.
|
guest ::
