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Photosynthetically produced hydrogen
Osipenko, Elena ; Němcová, Yvonne (advisor) ; Ráček, Jan (referee)
Bio-hydrogen from microalgae and cyanobacteria has attracted commercial awareness due to its potential as an alternative, reliable and renewable energy source. Photosynthetic hydrogen production from algae and cyanobacteria can be interesting and promising options for clean energy, because hydrogen is produced at ambient temperature and pressure and releases only water as a by-product. The energy of sunlight is used to split the water molecule into protons (H+), electrons (e-) and O2. The protons and electrons are then recombined with the help of the enzymes hydrogenase or nitrogenase (in the case of cyanobacteria) to form H2. Both of these enzymes are sensitive to O2 and therefore require the processes of H2 formation and CO2 fixation to be separated. This bachelor's thesis aims to describe the principle of H2 formation in different cyanobacterial and algal systems and mention the problems and limitations. The thesis also presents recent approaches, including genetic and metabolic engineering of cyanobacteria and algae or co-culturing of algae and bacteria, where an anaerobic environment is created by enhanced bacterial respiration.
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European black alder (Alnus glutinosa L. Gaertn.) in symbiosis with Frankia and their growth on post-mining heap soils
Buchbauerová, Lucie ; Frouz, Jan (advisor) ; Roubíčková, Alena (referee)
Alder (Alnus glutinosa L. Gaertn.) is a species of a pioneer plant usually colonizing sites in the early stage of ecological succession, such as spoil heaps after open-cast brown coal mining in the Sokolov mining district in north western Bohemia, Czech Republic. These spoil heaps are very poor in nutrients available for plants, yet alders grow in a mutualistic relationship with actinomycetes Frankia, which live in root nodules of the alder plants. Frankia are able of fixing atmospheric nitrogen (N2) to ammonia (NH3) molecules, which can be then assimilate by alders, via enzyme nitrogenase. Thus, in the early stages of succession, alders have a competitive advantage to other non- fixing plant species living only on nitrates (NO3 - ) and ammonia ions (NH4 + ) present in soils. The aim of this study was to conduct and assess two greenhouse experiments. The first experiment studied the response of alder growth to presence of Frankia and arbuscular mycorrhizal fungi of order Glomerales. The performance of alder growth was significantly higher when alders were inoculated with both Frankia and mycorrhizal fungi in comparison to when alders have grown on their own or only with a mycorrhizal symbiont - both on 14 and 60 years old soils from Sokolov mines. In the second experiment, soil pH and iron (Fe) and...
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