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Encapsulation of soil bacteria in hydrogel carriers
Orišková, Sofia ; Smilek, Jiří (referee) ; Sedláček, Petr (advisor)
The goal of this bachelor thesis was both to review existing literature regarding the topic of inoculation of soil bacteria and test a relevant encapsulation method and optimize it. The evaluation process involved the study of various encapsulation techniques that involve hydrogel carriers suitable for agronomic purposes. Encapsulation allows controlled release of soil bacteria, and protects and stabilizes it, while ensuring longer shelf life. For the practical testing, Cupriavidus necator H16 was chosen as a nitrogen fixing bacteria for the inoculation. Through an ionic gelation method, it was encapsulated into alginate carriers, forming matrix microcapsules. Sodium alginate reacts with the cross-linking agent calcium chloride to form the capsules. The impact on the quality of the product was tested through several variables. What was revealed was that molecular weight of alginate was proven to have a significant impact. Alginate with higher molecular weight was shown to be suitable for the given system. The most desirable environment was distilled water or a TRIS-HCl buffer. However, the TRIS-HCl was unsuitable in cases of retrieving a dry product by lyophilization. Eventually, the viability of encapsulated cells was examined, and it was proven that encapsulated bacteria endure the process of encapsulation in the above-mentioned environment and they were gradually released from the carrier.
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Encapsulation of soil bacteria in hydrogel carriers
Orišková, Sofia ; Smilek, Jiří (referee) ; Sedláček, Petr (advisor)
The goal of this bachelor thesis was both to review existing literature regarding the topic of inoculation of soil bacteria and test a relevant encapsulation method and optimize it. The evaluation process involved the study of various encapsulation techniques that involve hydrogel carriers suitable for agronomic purposes. Encapsulation allows controlled release of soil bacteria, and protects and stabilizes it, while ensuring longer shelf life. For the practical testing, Cupriavidus necator H16 was chosen as a nitrogen fixing bacteria for the inoculation. Through an ionic gelation method, it was encapsulated into alginate carriers, forming matrix microcapsules. Sodium alginate reacts with the cross-linking agent calcium chloride to form the capsules. The impact on the quality of the product was tested through several variables. What was revealed was that molecular weight of alginate was proven to have a significant impact. Alginate with higher molecular weight was shown to be suitable for the given system. The most desirable environment was distilled water or a TRIS-HCl buffer. However, the TRIS-HCl was unsuitable in cases of retrieving a dry product by lyophilization. Eventually, the viability of encapsulated cells was examined, and it was proven that encapsulated bacteria endure the process of encapsulation in the above-mentioned environment and they were gradually released from the carrier.
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Změny ve společenstvech půdní mikroflóry a mesofauny během rozkladu listového opadu ve dvou vegetačních zónách - litter bag experiment
Jirout, Jiří ; Petrásek, Jiří ; Čápová, Lenka ; Farská, Jitka ; Jínová, Kristýna ; Rusek, Josef ; Krištůfek, Václav ; Elhottová, Dana ; Starý, Josef ; Nováková, Alena
The hypothesis, whether autochthonous species of soil biota are able to decompose litter from lower vegetation zones in higher zones, was tested by field trial. Litterbags with litter of beech (.i.Fagus sylvatica./i. L.) and/or oak (.i.Quercus robur./i. L.) were exposed in beech and spruce forest on the mountain Kleť (Protected Landscape Area Blanský les). Litterbags layout simulated vegetation zones shift to the higher altitude induced by global warming. There were used litterbags with three different mesh size (42 µm, 0,5 mm, 2 mm) for exclusion of certain parts of edaphon. Several changes of soil bacteria and micromycetes, oribatid mites, springtails and gamasid mites were studied during two years of exposition. There were exposed 480 litterbags at the start of the experiment (November 2002). After 2, 4, 6, 12, 24 months of exposition parts of all litterbags were recovered. Immediately after the sampling litter pH(KCl), moisture and mass loss were measured.
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