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Effects of plants on the structure, function and diversity of bacterial communities
Havlíčková, Petra ; Baldrian, Petr (advisor) ; Kopecký, Jan (referee)
Vegetation is known to influence the composition of microbial communities. Bacteria can act as roots symbionts or be involved in the decomposition of plant biomass. They can be influenced by soil chemistry but also by plant exudates. Some plants produce targeted exudates to attract specific bacteria to their roots. Bacteria associate with plants frequently but the effect of plant diversity on bacterial communities on their roots and in the surrounding soil remains unclear. The aim of this work was to describe the relationship between the diversity and community composition of bacteria and the diversity of vegetation in forest and grassland ecosystems. The study areas were selected to represent a gradient of vegetation in Bohemian Forest NP and in White Carpathian flowery grasslands. I hypothesized that the diversity and evenness of bacterial community increase with increasing plant diversity. The composition of bacterial community was characterized by 16S rRNA sequencing. The composition of vegetation was determined by phytocenological relevées and by molecular markers trnL. In grassland ecosystem, there was a positive relationship between plant and bacterial diversity only in shoots. The space and vegetation were identified as an important drivers of bacterial community composition in shoots. The...
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determination of kinetic parameter of reactions using DSC
Kopecký, Jan ; Kouřil, Miloslav (referee) ; Jan, Vít (advisor)
The master thesis deals with DSC measurments a calculation of kinetic parameters. In the theoretical part, iron alotropy is briefly described, followed by a description of the DSC analysis itself. The thesis also includes division and derivation of isoconversional methods for calculating the activation energy. In the experimental part, a series of measurments is perfomed on pure iron prepared by Cold Spray method. In the paper the influence of deformation on the Curie temperature of the magnetic transformation in -Fe and transformation > is investigated. The activation energy is calculated for transformation > for different degrees of deformation. The degree of deformation is monitored by channeling contrast.
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Design of synchronous spoke motor
Kopecký, Jan ; Bulín, Tomáš (referee) ; Knebl, Ladislav (advisor)
This thesis is focused mainly on the theoretical research of permanent magnet synchronous motors. In addition, various methods of designing the motor‘s magnetic circuit are discussed and their advantages and disadvantages are compared. The reluctance network method is analyzed more thorough, because this method is used for motor designing process. In the last part the results obtained by reluctance network are compared with the results evaluated by finite element method.
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Modulation of body fat content by targeting the lipid metabolism of adipose tissue
Šponarová, Jana ; Kopecký, Jan (advisor) ; Konvalinka, Jan (referee) ; Drahota, Zdeněk (referee)
CONCLUSIONS 1. Induction of obesiý resistance in mice by transgenic expression of UCP1 in white fat can be explained by a metabolic switch ínadipocýes, due to depressíon oť celluiar energy charge, in situ activaÍion of AMPK, down- regulation ofadipogenic genes and increase in lipid oxidation. 2. AMPK cascade is involved in the fat depot-specific metabolic responses in various fat depots to starvation. Activation of the cascade occurred in epididymal but not in subcutaneous fat in mice. The activation of AMPK in adipocytes might represent an important mechanism by which body fat stores are regulated and may contributes to regional differences in the metabolic properties ofadipose tissue depots. Dietary EPA and DHA reduce development of obesity induced in mice by high fat diets, in part due to counteracting increase in tissue cellularity, particularly in epididymal íat.Low EPA/DHA ratio potentiates the anti- adipogenic efíect. Dietary EPA and DHA induce a metabolic shift in white adipose tissue by up-regulating genes for mitochondrial proteins, including their regulatory genes PGCIa and NRF-I, and increase B-oxidation while depressing lipogenesis, preferentially in the epididymal fat in the abdomen. 3. 4. J. 21
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The effect of the hosts immune response on sand fly bloodfeeding and fecundity
Hrabcová, Luisa ; Volf, Petr (advisor) ; Kopecký, Jan (referee)
The main aim of this thesis was to prove the hypothesis that the intake of blood with specific antibodies against sand fly saliva affects sand fly fecundity and mortality. Phlebotomus argentipes and Mesocricetus auratus were used for most experiments. ELISA revealed high levels of specific antibodies in repeatedly exposed hosts. However, a five-day study of mortality and fecundity of bloodfed females demonstrated that feeding on repeatedly bitten hamsters has no effect on number of eggs or survival of females. Salivary antigens of P. argentipes recognized by sera of repeatedly bitten hamsters were characterized by immunoblotting and mass spectrometry. Immunoblotting showed that antibodies in the hamster sera recognize salivary proteins with molecular weight from 25 to 60 kDa. Mass spectrometry revealed that the antigens correspond to D7, apyrases, antigen 5-related proteins and yellow-related proteins. In addition, Phlebotomus females were fed through a chicken membrane on rabbit blood with high concentrations of histamine, serotonin or prostaglandin E2 to find out if they influence fecundity or mortality of sandfly females. While the approximate number of eggs layed by one female did not significantly differ from controls in any experimental group studied, the total mortality of females was lower...
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The identification of biosynthetic clusters in the soil isolates of actinomycetes.
Pavlíková, Magdaléna ; Najmanová, Lucie (advisor) ; Kopecký, Jan (referee)
Pyrrolobenzodiazepines (PBDs), predominantly produced by microorganisms from the genus Streptomyces, belong to a group of secondary metabolites with significant antitumor activity. A key role in the biosynthesis of PBDs have nonribosomal peptide synthetases, which catalyze the condensation of anthranilate subunit with prolin or proline derivative resulting in tricyclic PBD molecule, which can be subsequently further substituted. Five biosynthetic gene clusters have been published yet. The aim of this diploma thesis was to identify and characterize the biosynthetic gene cluster (or clusters) for the biosynthesis of PBDs limazepines. The producer of limazepines is the only yet identified strain, which produces both the PBDs hydroxylated at C9 position and compounds unsubstituted in this position simultaneously. According to already published data, in the biosynthesis of PBDs hydroxylated at position C9 the kynurenine pathway is involved, while the biosynthesis of the C9 unsubstituted PBDs employes the chorismate biosynthetic pathway. Moreover, according to the previously published data, the PBDs produced by this model strain incorporate three different proline derivatives, two of them being described as a structural part of a PBD molecule for the first time. Based on the results of this diploma...
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Energy Metabolism in Obesity: Metabolic Flexibility and Dietary Fat
Bardová, Kristina ; Kopecký, Jan (advisor) ; Drahota, Zdeněk (referee) ; Žurmanová, Jitka (referee)
Abstract Adipose tissue is an important homeostatic tissue within the body. It not only buffers FA availability in the organism, but also releases important autocrine, paracrine or endocrine factors influencing energy metabolism. The biology of adipose tissue is closely related and underlies whole-body metabolic consequences of obesity, such as type II. diabetes. Obesity and type II. diabetes causes and maybe are caused by metabolic inflexibility, the inability of organism to adapt fuel oxidation to fuel availability. The intersection of adipose tissue biology, obesity and its metabolic consequences and theory of metabolic flexibility is discussed in this PhD. thesis. Five articles dealing with above mentioned topics are included. The general goal of this study was to compare several approaches for metabolic flexibility assessment with respect to overall energy homeostasis. The specific goals, delineated by included articles, were (i) to evaluate the influence of n-3 long chain fatty acids (n-3 LC-PUFA), rosiglitazone, and their combination, on metabolic flexibility at a whole-body and cellular level; (ii) to evaluate impact of high-fat feeding on metabolic flexibility of male and female mice; (iii) to evaluate the impact of chenodeoxycholic acid (CDCA)...
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