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Kontinuální analýzy DNA translokace enzymem Typu I EcoR124I
Šišáková, Eva ; Seidel, R. ; Szczelkun, M. ; Weiserová, Marie
Using combination of bulk solution and single-molecule assays we have investigated the influence of several mutations in the PD-(D/E)-X-K catalytic motif of HsdR on the DNA translocation and ATPase properties of EcoR124I, the restriction-modification enzyme Type I. The gained results have given us the insight into the possible interdomain interactions between helicase and nuclease domains of the HsdR subunit and the effect of their interactions on DNA translocation
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Spatial and temporal dynamics of enzyme activity distribution in soils with respect to soil fungi
Baldrian, Petr ; Šnajdr, Jaroslav ; Valášková, Vendula ; Cajthaml, Tomáš ; Merhautová, Věra
Activity of laccase, Mn-peroxidase, endo-1,4-β-glucanase, endo-1,4-β-xylanase, cellobiohydrolase, β-glucosidase and β-xylosidase in forest soil (with dominant Quercus sp.) exhibited high but inconsistent variation. Enzyme activity decreased with soil depth as well as fungal biomass and the fungal/bacterial biomass ratio
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Zvýšená koncentrace CO2 zvýší fixaci dusíku a růst mořské sinice Trichodesmium IMS101
Levitan, O. ; Prášil, Ondřej ; Berman-Frank, I.
Anthropogenic increases in atmospheric pCO2 over the last century are accompanied by higher concentrations of CO2 (aq) in the surface oceans. These changes could influence aquatic primary production including cyanobacterial nitrogen-fixers via the coupling between photosynthesis and nitrogen-fixation. We hypothesized that elevated pCO2 levels may enhance nitrogen fixation and photosynthesis in the bloom-forming, diazotrophic, cyanobacterium Trichodesmium spp. that contributes greatly to primary production in the oligotrophic subtropical and tropical oceans. We acclimated cultures of Trichodesmium IMS101 to 3 pCO2s (pre-industrial -250 ppmv, current - 400, future -900 ppmv) and examined changes in morphology, photosynthesis, nitrogen fixation, and growth. High pCO2 enhanced growth, filament length and nitrogen fixation of Trichodesmium in comparison with both ambient and low pCO2 acclimated cultures
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Fotosyntetické cirkadiální rytmy u mořské rozsivky Thalassiosira weissflogii v podmínkách dostatku a nedostaku dusíku
Kasalický, Vojtěch ; Rottnerová, K. ; Sciandra, A. ; Babin, M. ; Prášil, Ondřej
T. weissflogii was grown under dynamic irradiance conditions (sinusoidal light-dark regime) and then switched to constant, low irradiance. Cellular characteristics (pigment and nutrient content, cell size) indicated synchronization of algal population, furthermore pronounced variations in the aktivity of variable fluorescence, thermoluminescence and in the gene expression (rbcL, psbA, fcp) were observed
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