National Repository of Grey Literature 112 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Ergothioneine and mycothiol in the biosynthesis of lincosamides
Seidlová, Bára ; Kameník, Zdeněk (advisor) ; Kopecký, Jan (referee)
Specialized microbial metabolites are described as low-molecular-weight bioactive compounds, which are dispensable for the growth, evolution, or reproduction of its producer. This group of substances includes the lincosamides, which are produced mainly by the bacteria of the Streptomyces genera. Apart from other precursors, two low-molecular-weight thiols, ergothioneine and mycothiol, are essential participants of the lincosamide biosynthesis. Mycothiol (MSH) serves in this pathway as a source of sulphur, on the other hand, ergothioneine (ESH) constitutes a conjugate with the aminosugar moiety of lincosamide structure. The conjugate is condensed with an activated amino acid, which is catalyzed by an unusual enzyme to form a core of the lincosamide molecule. The objective of this diploma thesis is to isolate the conjugate of ESH and aminooctose, which serves as a substrate of the LmbD biosynthetic protein. Another aim is to study the links between the thiol metabolism and the biosynthesis of three lincosamides, lincomycin, celesticetin, and intervencin, which are produced by different bacterial strains. Bacterial strains were cultivated under laboratory conditions and methods of liquid chromatography with UV and MS detection were used for the analysis. The parameters of the methods were developed...
Soil microbial communities in agroecosystems and natural habitats contributing to resistance and resilience of the soil environment
Sarikhani, Ensyeh ; Kopecký, Jan (advisor) ; Demnerová, Kateřina (referee) ; Větrovský, Tomáš (referee)
Ensyeh Sarikhani Soil microbial communities in agroecosystems and natural habitats contributing to resistance and resilience of the soil environment. Summary The control of common scab of potatoes (CS) includes resistant varieties (cultivars), precise fertilization, increase of soil moisture, and chemical treatments. Yet, these management practices do not have common or reproducible results at differing sites. A monitoring study was done in 32 sites to evaluate the relation between CS and biological/chemical soil parameters. Correlations were observed between scab severity and content of nutrients such as Fe, N, and Ca in soil and periderm, and between disease severity and abundance of actinobacteria and total bacteria, together with the pathogenicity determinant, txtB gene (biosynthetic gene of thaxtomin) in both soil and periderm of potatoes. The findings led to novel conclusions, which can help to understand relationships applicable in scab control. Peat and DTPA chelated iron were supplemented to pots filled with soil conducive for CS in order to determine the effects of soil organic matter, iron and pH on CS development. The results were compared with data obtained for a suppressive soil from a nearby field with naturally low CS severity. Both peat and iron supplements decreased CS and the combination...
Control circuits of railway lift
Kopecký, Jan ; Lažek, Tomáš (referee) ; Huták, Petr (advisor)
This master thesis deals with the mechanical and electrical design of the drive of the inclined construction lift. Individual components are selected in the design. Furthermore, a theoretical research is carried out regarding wireless modules and logic controllers. The selection of sensors is made and the method of retrieving signals from sensors and converting them into iputs the control circuits is also outlined. A program is written in Arduino IDE that wirelessly controls the motion of a motor via variable frequency drive.
Development of a new sand fly exposure test to evaluate vector control tools
Willen, Laura Adrienne André ; Volf, Petr (advisor) ; Kopecký, Jan (referee) ; Valenzuela, Jesus G. (referee)
In the Mediterranean basin, human visceral leishmaniasis caused by the protozoan parasite Leishmania infantum is a zoonotic disease that gives rise to 1,200 to 2,000 new cases annually. The domestic dog constitutes its main reservoir, of which some may suffer from a severe chronic disease, canine leishmaniasis (CanL). The sand fly Phlebotomus perniciosus is considered to be the principle vector. Saliva of bloodfeeding vectors of diseases has been used in the past to assess host exposure to vector bites and to evaluate vector control tools. This Ph.D. focused on saliva of P. perniciosus to identify exposure markers that could be used in the preparation of a new vector exposure tool. The first part of this Ph.D. aimed at validating the use of a recombinant salivary protein of P. perniciosus - rSP03B - in endemic settings of CanL. During a cross-sectional study, no significant differences between the antibody (Ab) response against whole saliva or the rSP03B were observed between different regions across the Mediterranean basin. Furthermore, the rSP03B was shown to resemble the native protein. During a subsequent study this protein was used to assess the seasonal dynamics of the canine Ab response to P. perniciosus in an endemic area of L. infantum. This study elucidated that also in a heterogeneous...
Gene pool of the secondary metabolism in soil bacterial communities
Patrmanová, Tereza ; Kopecký, Jan (advisor) ; Brabcová, Vendula (referee)
The need for new antibiotics and other biologically active compounds is the reason for an increased interest in secondary metabolites of soil bacteria. The phylum Actinobacteria has the dominant position in the soil environment thanks to the potential of producing a broad spectrum of antibiotics and the presence of a number of defense mechanisms preventing the effects of antibiotics. The aim of this thesis was to determine the number of copies of selected secondary metabolic genes in the soils of two sites using designed primers and primers from literature. The design of effective new primers for the detection of selected genes in the soil environment was not achieved in this work, and therefore only primers from literature that had been verified for their specificity were used. In samples taken from soil profiles of two sites, abundances of bacteria, actinobacteria, type II polyketide synthase genes and Erm methyltransferase genes mediating resistance to MLSB antibiotics (macrolides, lincosamides and streptogramins B) were determined by digital PCR. The comparison of the determined copy numbers gave an information about the structure of the bacterial community and the relative abundance of bacteria carrying selected secondary metabolic genes depending on the soil condition changes due to the...
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...
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.
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.

National Repository of Grey Literature : 112 records found   1 - 10nextend  jump to record:
See also: similar author names
12 KOPECKÝ, Jiří
5 Kopecký, Jakub
1 Kopecký, Jaroslav
1 Kopecký, Jindřich
1 Kopecký, Jindřich Bc.
12 Kopecký, Jiří
12 Kopecký, Jiří
2 Kopecký, Josef
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