National Repository of Grey Literature 9 records found  Search took 0.01 seconds. 
Utilization of physico-chemical and spectroscopical methods in study on microbial extremofiles
Dobešová, Kateřina ; Enev, Vojtěch (referee) ; Sedláček, Petr (advisor)
The aim of this bachelor thesis is the determination od polyhydroxyalkanoates in the cells of extremophille bacterie, preformed by several methods. The chosen bacterium was Schlegelella thermodepolymerans DSM 15 344 Thermogravimetric analysis, infrared spectroscopy with Fourier transformation, and Raman spectroscopy were used in this thesis. The TGA method was used for the determination of extracellular and intracellular water in samples. The FTIR method was used in order to observe the amount od PHA, but aslo to observe the physical properties of the polymer in the sample, specifically to determine either amorphous or crystalline featuers of this polymer. Raman spectroscopy was used in oder to confirm the presence of PHA in the samples. All results e´were compared eith the results accomplished by gas chromatografy.
Study on production of polyhydroxyalkanoates by psychrophilic bacteria
Šlosárová, Katarína ; Sedlář, Karel (referee) ; Pernicová, Iva (advisor)
Baktérie produkujú polyhydroxyalkanoáty (PHA) za účelom vnútrobunkových zásob uhlíka a energie. Z technologického hľadiska majú veľký potenciál ako biologicky odbúrateľné verzie bežných plastov. Ich hlavnou nevýhodou v porovnaní s nimi sú však vysoké výrobné náklady. Výskum sa preto zameriava na spôsoby, ako túto prekážku prekonať, pričom jedným z nich je použitie kmeňov extrémofilných mikroorganizmov. Množstvo výskumov so psychrofilami je však v porovnaní s inými typmi extrémofilov menšie. V tejto práci sú uvedené výsledky prvého skríningu zahŕňajúceho 78 bakteriálnych kmeňov adaptovaných na chlad izolovaných z východnej Antarktídy. Na výber potenciálnych producentov PHA sa použili genotypové aj fenotypové metódy. Polymerázová reťazová reakcia predovšetkým preukázala prítomnosť génov kódujúcich PHA syntázy, konkrétne PHA syntázy triedy I a II. Farbenie Nílskou červenou a Sudánskou čerňou B, ako typická metóda prvotného skríningu z fenotypovej úrovne, neposkytlo smerodajné výsledky u psychrofilov a/alebo psychrotolerantov. V tejto práci sa na zisťovanie prítomnosti PHA, ktorá sa neskôr potvrdila plynovou chromatografiou, použila FTIR spektroskopia v kombinácii s vysokovýkonným mikrokultivačným systémom (Duetz-MTPS). Kultivácia sa uskutočnila na piatich rôznych médiách. Na základe všetkých výsledkov bola najvyššia produkcia biomasy a zároveň akumulácia PHA zaznamenaná u Pseudomonas sp. patriaceho k izolátom zo zeleného snehu. Zaujímavé je, že zvýšená syntéza PHA, konkrétne P(3HB), bola pozorovaná na komplexnom BHI médiu s dodatočným prídavkom glukózy nepredstavujúcim limitáciu dusíkom, ktorá je typická pri stimulácii syntézy a akumulácii PHA. Možno zhodnotiť, že prítomnosť sľubných producentov medzi polárnymi baktériami bola potvrdená a výťažok PHA je naďalej možné navýšiť optimalizáciou zloženia média a rastových podmienok.
Detecting biomarkers of extremophiles in Martian analogues
Němečková, Kateřina ; Jehlička, Jan (advisor) ; Hauer, Tomáš (referee) ; Vandenabeele, Peter (referee)
The main focus of this thesis is on the examination of endolithic microorganisms within gypsum from Sicily. This region is of particular interest because gypsum outcrops are common and accessible there, but the environment is not considered to be extreme in terms of solar radiation or other factors. The research aims to detect endolithic biomarkers and analyse their distribution in their natural environment, to identify endoliths with a focus on phototrophs, and to assign the detected biomarkers to their producers. One of the key tools used in this study was a portable Raman spectrometer with a 532 nm laser, used for the detection of carotenoids under field conditions. Further, the Raman fingerprints of scytonemin and gloeocapsin can be used for the taxonomic identification of some cyanobacteria. With the use of a combination of different excitation wavelengths (445nm, 532 nm, 780 nm), it was possible to detect good quality spectra of various pigments in situ, conditions also in isolated cells and colonies. The results of the molecular analysis also suggest that gypsum habitats in non-extreme regions have a similar microbial composition as those found in extreme regions; i.e., Cyanobacteria being the most abundant group of these microorganisms. This has previously been described as the "hypothesis...
Extreme environment of the Atacama Desert: Geology, Extremophiles, and its connection to Exobiology
Jíra, Stanislav ; Culka, Adam (advisor) ; Vítek, Petr (referee)
Because of the position in the subtropical climate belt, high altitudes, cold Humboldt Current, Andean rain-shadow, and a few other factors, the Atacama Desert is known for its hyper-arid conditions which are persisting here for a few tens of millions of years. That is why this place is called the driest non-polar place in the world. Aridity is present here since Mesozoic. Because of these conditions, Atacama was thought to be completely inhabitable and inappropriate for any life forms. Despite all the limiting factors, microbial life here exists. Microorganisms have created adaptations in the forms of specialized metabolisms, proteins, and most importantly in form of photoprotective pigments. Except for the structural mechanisms, extremophiles can choose a strategy of living evaporitic minerals, which are quite common in Atacama. For understanding these forms of life many scientific methods are used, for example Raman spectroscopy. Methods that are used here are often used also in extraterrestrial conditions, mainly on the planet Mars, which shares with Atacama few similarities (e.g., some evaporitic minerals). The study of adaptations and capabilities of extremophilic microorganisms can help to broaden the knowledge and understanding of how incredibly resilient life is. Keywords: The Atacama...
Utilization of physico-chemical and spectroscopical methods in study on microbial extremofiles
Dobešová, Kateřina ; Enev, Vojtěch (referee) ; Sedláček, Petr (advisor)
The aim of this bachelor thesis is the determination od polyhydroxyalkanoates in the cells of extremophille bacterie, preformed by several methods. The chosen bacterium was Schlegelella thermodepolymerans DSM 15 344 Thermogravimetric analysis, infrared spectroscopy with Fourier transformation, and Raman spectroscopy were used in this thesis. The TGA method was used for the determination of extracellular and intracellular water in samples. The FTIR method was used in order to observe the amount od PHA, but aslo to observe the physical properties of the polymer in the sample, specifically to determine either amorphous or crystalline featuers of this polymer. Raman spectroscopy was used in oder to confirm the presence of PHA in the samples. All results e´were compared eith the results accomplished by gas chromatografy.
Extremophiles and their environments - possibilities of using Raman spectroscopy for key biomarkers detection
Kovács, Michal ; Jehlička, Jan (advisor) ; Osterrothová, Kateřina (referee)
The Earth has a huge variety of living environments. Most of them, in terms of human, are affected by factors with extreme values. Species diversity, especially in the world of microorganisms, have created adaptations that help manage these conditions. Organisms, which live in these conditions, are called extremophiles. Each of them leaves a trace of their existence, whether present or past. These traces are called biomarkers and if we use appropriate method, we are able to identify them. This bachelor thesis brings a brief overview of the basic extremophiles and the environment in which they live. Furthermore, briefly describes the use of Raman spectroscopy to identify significant biomarkers, such as for the needs of exobiology.
Effect of temperature on life cycle of zygomycetes
Matoušková, Barbora ; Kubátová, Alena (advisor) ; Nováková, Alena (referee)
This thesis is aiming on zygomycetes, their importance, their current position in the Fungi kingdom and above all their ecological demands. The paper summarizes the influence of temperature on their life cycle (i.e. primarily on the growth, reproduction and production of metabolites). It focuses mainly on psychrophilic and thermophilic species and describes the mechanisms of adaptation to unfavorable living conditions. To investigate the influence of temperature, zygomycetes are exceptionally suitable model organisms, e.g. in the order Mucorales we can find relatives growing in diametrically different environments. Among the mechanisms of extreme temperature adaptation for zygomycetes are in particular trehalose production, a change in the degree of saturation of membrane phospholipids and the production of membrane stabilizing agents - sterols, glycolipids and sugar alcohols. Key words: temperature, growth, reproduction, life cycle, habitat, extremophiles, Mucoromycotina, Mortierellomycotina
Microorganisms as the primary producers in photosynthesis-independent ecosystems
Burkartová, Kateřina ; Falteisek, Lukáš (advisor) ; Lhotský, Josef (referee)
Chemolithotrophy and photoautotrophy are the two basic principles of primary production on Earth. This thesis focuses on the relation between chemolithotrophic and oxygen-productive photosynthetic microorganisms in a global dimension. There are high atmospheric oxygen concentration, high sulfate in seawater and other oxidants because of oxygen-productive photosynthesis. These compounds are commonly consumed by chemolithotrophs to oxidize reduced inorganic compounds. It is a question, if there are chemoautotrophic ecosystems profiting only from abiotically derived substrates. It is essential to combine geochemical and metagenomic approaches in order to enhance both establishing of the origin of substrates and assessing the metabolism which utilizes them in the tested ecosystem respectively. Two well established types of photosynthetic independent ecosystems that use serpentinization hydrothermal venting and radiolysis of water as a source of energy are known at present time. The absence of photosynthesis-derived final electron acceptors for chemolithotrophy and the proper spatial separation from areas where photosynthetically derived organic matter and oxidants are present can be a useful clue for this investigation. The goal of this thesis is to describe geological processes which provide not only...
Extremophiles and their environments - possibilities of using Raman spectroscopy for key biomarkers detection
Kovács, Michal ; Jehlička, Jan (advisor) ; Osterrothová, Kateřina (referee)
The Earth has a huge variety of living environments. Most of them, in terms of human, are affected by factors with extreme values. Species diversity, especially in the world of microorganisms, have created adaptations that help manage these conditions. Organisms, which live in these conditions, are called extremophiles. Each of them leaves a trace of their existence, whether present or past. These traces are called biomarkers and if we use appropriate method, we are able to identify them. This bachelor thesis brings a brief overview of the basic extremophiles and the environment in which they live. Furthermore, briefly describes the use of Raman spectroscopy to identify significant biomarkers, such as for the needs of exobiology.

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