|
|
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...
|
|
|
Analysis of streptomycete isolates carrying a cyclizing aminolevulinate synthase gene
Rašmanová, Petra ; Petříčková, Kateřina (advisor) ; Felsberg, Jurgen (referee)
Streptomyces bacteria are well-known producents of many bioactive metabolites. Its secondary metabolism is a source of many important groups of active compounds that are recently investigated by means of many new methods based on bioinformatic analyses of genome data, modern LC-MS techniques, and metabolic modeling methods. This thesis originates from the genetic screening for a specific gene (als) for cyclizing 5-aminolevulinate synthase. Based on earlier studies, we consider this gene as a genetic tag of the producers of secondary metabolites containing the C5N unit (2-amino-3-hydroxycyklopent- 2-enon). Such metabolites include several groups with variable structures and biological activities, which include manumycins as well. Manumycins are small polyketides with a weak antibiotic aktivity, especially against gram-positive bacteria. However, its cancerostatic and anti-inflammatory effects are of greater importance. Streptomyces monomycini BCCO10 1552 and Streptomyces capoamus BCCO10 1636 strains were found positive for the presence of the als gene in the targeted genetic screening. By the als phylogeny, they cluster near the producents of manumycin compounds. This thesis aimed to determine whether these new natural isolates produce any compounds containing C5N unit, and to characterize them in...
|
|
|
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...
|
|
|
The genetic basis of Czech garlic "paličák" (A. sativum L. ssp. ophioscorodon) focusing on the biosynthetic pathways of the secondary metabolites
Čermák, Vladimír ; Ovesná, Jaroslava (advisor) ; Demnerová, Kateřina (referee)
Czech bolting garlic (Allium sativum L.) is the name for Czech varieties, which are categorized into subspecies sativum ssp. An inflorescence production and specific onion morphology is typical for this type of garlic. The genetic basis, that has been described by the analysis of microsatellites, are discussed in this thesis. Transcription analysis has revealed a large number of unigenes that have been assigned by genetic ontology to individual functions in the organism. Therefore, genetic differences from other varieties were confirmed. The impact of the environment and cultivation practices, including large- scale production, is being explored. The results can be used for further research or breeding. Consumers and experts have rated the Czech bolting garlic as a variety with a distinctly pungent taste and aroma. Substances causing this strong characteristic taste are secondary metabolites, alk(en)ylcysteine-S-oxides (ACSO), especially alliin and methiin. Chemical analysis did not confirm the exceptionally high value of these taste precursors or other substances that should distinguish Czech bolting garlic. Secondary metabolism includes other important substances that are used mainly in pharmacy and healthcare, where garlic has been used for thousands of years due to antibacterial effects,...
|
|
|
Composition and activity of microbial community during decomposition of plant litter on two contrasting localities
Burešová, Andrea ; Marečková, Markéta (advisor) ; Tejnecký, Václav (referee)
Decomposition of organic matter in soil is influenced by abiotic and biotic factors and their role is different depending on site, organic substrate and its decomposition phase. Soil microbial community influences soil organic decomposition process in a different way, which is manifested, for example, by changes of microbial abundance and production of extracellular enzymes. The thesis aimed in determining relationship of two main soil microbial decomposers groups - fungi and actinobacteria in decomposition processes in situ. The impact of selected factors on decomposition processes were determined by experiment with litterbags, which were filled with litter of plant with different properties. Astragalus exscapus from the Fabaceae family contains high amounts of nitrogen in the tissues, Fagus sylvatica contains high amounts of carbon and lignin and Carex humilis has less carbon in the tissues than Fagus sylvatica falling in tissue element composition between Astragalus exscapus and Fagus sylvatica. Litterbags with three plant species were put under a litter layer at both contrasting sites. Litterbags and samples of soil were collected every two months during the years 2011-2012. Each litterbag was weighted, DNA was isolated from litter and soil samples and analyses of quantitative real time PCR...
|
guest ::
