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Structure and evolution of efflux pump in gramnegative bacteria.
Gálová, Diana ; Lichá, Irena (advisor) ; Matyska Lišková, Petra (referee)
Drug resistence in microorganisms is of major concern and there is an increasing number of pathogenic bacteria resistent to clinically used antibiotics. The major mechanism of resistence in Gram-negative is active efflux that prevent the intracellular accumulation of antibiotics to toxic levels. We recognise five families of efflux pumps, mainly using proton motive force to translocate the substrate, less common driven by ATP hydrolysis. The multidrug pumps with broad substrate specifity are of a key role in drug resistance of pathogens, typically represented by RND superfamily. The source of efflux pumps are probably the producers of antibiotics and organisms exposed to toxic compounds in their natural habitat. The genes for resistance can then spread out via horizontal gene transfer to other bacteria. It is presumed that eflux pumps have developed from transporters serving physiological functions like transport of endogenous substrates.
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Cellulolytic fungi and their diversity on plant litter
Gálová, Diana ; Baldrian, Petr (advisor) ; Kolařík, Miroslav (referee)
Litter decomposition requires the presence of corresponding degradative enzymes, produced mainly by fungi. Forest soils show considerable spatial heterogeneity of distribution of these enzymes at diferent scales. Moreover, enzyme pruduction varies during the year, usually accompanied by the change in fungal community composition. In this work I examined if this spatial heterogeneity can be seen even at a scale of an individual leaf and whether the fungal community differs among enzyme activity hotspots and inactive parts of the leaves. Another goal was isolation of celulytic fungi from cellulose litterbags incubated on forest floor using particle filtration and dilution-to-extinction method. In a broadleaved forest dominated by oak leaves at different stages of decay were collected: senescent leaves on twigs, and leaves after 2, 10 and 22 months of decomposition. Ten leaves per season were taken for analysis of cellobiohydrolase activity over the leaf surface. Leaves were attachmed onto melted agarose plate and leaf surface was covered with low melting point agarose containing fluorescently labelled substrate. For each leaf a map of enzyme activity was created and area with the high and low enzyme activity was identified. From both sites a square of approx. 1 cm2 was cut out, DNA was extracted and fungal...
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Cellulolytic fungi and their diversity on plant litter
Gálová, Diana ; Baldrian, Petr (advisor) ; Kolařík, Miroslav (referee)
Litter decomposition requires the presence of corresponding degradative enzymes, produced mainly by fungi. Forest soils show considerable spatial heterogeneity of distribution of these enzymes at diferent scales. Moreover, enzyme pruduction varies during the year, usually accompanied by the change in fungal community composition. In this work I examined if this spatial heterogeneity can be seen even at a scale of an individual leaf and whether the fungal community differs among enzyme activity hotspots and inactive parts of the leaves. Another goal was isolation of celulytic fungi from cellulose litterbags incubated on forest floor using particle filtration and dilution-to-extinction method. In a broadleaved forest dominated by oak leaves at different stages of decay were collected: senescent leaves on twigs, and leaves after 2, 10 and 22 months of decomposition. Ten leaves per season were taken for analysis of cellobiohydrolase activity over the leaf surface. Leaves were attachmed onto melted agarose plate and leaf surface was covered with low melting point agarose containing fluorescently labelled substrate. For each leaf a map of enzyme activity was created and area with the high and low enzyme activity was identified. From both sites a square of approx. 1 cm2 was cut out, DNA was extracted and fungal...
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Structure and evolution of efflux pump in gramnegative bacteria.
Gálová, Diana ; Lichá, Irena (advisor) ; Matyska Lišková, Petra (referee)
Drug resistence in microorganisms is of major concern and there is an increasing number of pathogenic bacteria resistent to clinically used antibiotics. The major mechanism of resistence in Gram-negative is active efflux that prevent the intracellular accumulation of antibiotics to toxic levels. We recognise five families of efflux pumps, mainly using proton motive force to translocate the substrate, less common driven by ATP hydrolysis. The multidrug pumps with broad substrate specifity are of a key role in drug resistance of pathogens, typically represented by RND superfamily. The source of efflux pumps are probably the producers of antibiotics and organisms exposed to toxic compounds in their natural habitat. The genes for resistance can then spread out via horizontal gene transfer to other bacteria. It is presumed that eflux pumps have developed from transporters serving physiological functions like transport of endogenous substrates.
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