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- ItemThe First Insight into Polyhydroxyalkanoates Accumulation in Multi-Extremophilic Rubrobacter xylanophilus and Rubrobacter spartanus(MDPI, 2021-05-01) Kouřilová, Xenie; Schwarzerová, Jana; Buchtíková, Iva; Sedlář, Karel; Mrázová, Kateřina; Krzyžánek, Vladislav; Nebesářová, Jana; Obruča, StanislavActinobacteria belonging to the genus Rubrobacter are known for their multi-extremophilic growth conditions-they are highly radiation-resistant, halotolerant, thermotolerant or even thermophilic. This work demonstrates that the members of the genus are capable of accumulating polyhydroxyalkanoates (PHA) since PHA-related genes are widely distributed among Rubrobacter spp. whose complete genome sequences are available in public databases. Interestingly, all Rubrobacter strains possess both class I and class III synthases (PhaC). We have experimentally investigated the PHA accumulation in two thermophilic species, R. xylanophilus and R. spartanus. The PHA content in both strains reached up to 50% of the cell dry mass, both bacteria were able to accumulate PHA consisting of 3-hydroxybutyrate and 3-hydroxyvalerate monomeric units, none other monomers were incorporated into the polymer chain. The capability of PHA accumulation likely contributes to the multi-extremophilic characteristics since it is known that PHA substantially enhances the stress robustness of bacteria. Hence, PHA can be considered as extremolytes enabling adaptation to extreme conditions. Furthermore, due to the high PHA content in biomass, a wide range of utilizable substrates, Gram-stain positivity, and thermophilic features, the Rubrobacter species, in particular Rubrobacter xylanophilus, could be also interesting candidates for industrial production of PHA within the concept of Next-Generation Industrial Biotechnology.
- ItemNovel Riboflavin-Inspired Conjugated Bio-Organic Semiconductors(MDPI, 2018-09-05) Richtár, Jan; Heinrichová, Patricie; Apaydin, Dogukan Hazar; Schmiedová, Veronika; Yumusak, Cigdem; Kovalenko, Alexander; Weiter, Martin; Sariciftci, N.S.; Krajčovič, JozefFlavins are known to be extremely versatile, thus enabling routes to innumerable modifications in order to obtain desired properties. Thus, in the present paper, the group of bio-inspired conjugated materials based on the alloxazine core is synthetized using two efficient novel synthetic approaches providing relatively high reaction yields. The comprehensive characterization of the materials, in order to evaluate the properties and application potential, has shown that the modification of the initial alloxazine core with aromatic substituents allows fine tuning of the optical bandgap, position of electronic orbitals, absorption and emission properties. Interestingly, the compounds possess multichromophoric behavior, which is assumed to be the results of an intramolecular proton transfer.
- ItemOhlas od Nežárky a jeho podíl na poznání regionální a lokální historie na příkladu dějin Stráže nad Nežárkou a pánů ze Stráže(Národní muzeum, 2023-02-17) Maráz, KarelOhlas od Nežárky byl jedním z nejdéle vycházejících regionálních kulturních týdeníků. Jednalo se o periodikum pro poučení i zábavu, které věnovalo značnou pozornost (nejen regionální a místní) historii. Vzhledem k vysoké kvalitě různorodých textů, které v něm publikovali nejrůznější odborníci a znalci, je zmiňován například v Přehledných dějinách českého a slovenského dějepisectví. Soupis článků z jednotlivých čísel regionálního masmédia z dané doby již byl publikován, ale dosud postrádáme podrobné rozbory jeho textů k vybraným lokalitám a problémům. Patří k nim například historie Stráže nad Nežárkou, která nebyla zpracována v žádné moderně koncipované publikaci, a osudy pánů modré pětilisté růže. Oběma se autor ve svém článku věnuje. Analyzuje obsah publikovaných textů ke konkrétním otázkám a jejich vypovídací hodnotu v dobovém kontextu a ve světle poznatků současných historických disciplín. Upozorňuje také na informační, metodologické, žánrové a formální přístupy jednotlivých přispěvatelů.
- ItemPhysicochemical Properties of Tungsten Trioxide Photoanodes Fabricated by Wet Coating of Soluble, Particulate, and Mixed Precursors(MDPI, 2024-02-01) Chittoory, Valli Kamala Laxmi Ramya; Filipská, Markéta; Bartoš, Radim; Králová, Marcela; Dzik, PetrAdvanced oxidation processes are emerging technologies for the decomposition of organic pollutants in various types of water by harnessing solar energy. The purpose of this study is to examine the physicochemical characteristics of tungsten(VI) oxide (WO3) photoanodes, with the aim of enhancing oxidation processes in the treatment of water. The fabrication of WO3 coatings on conductive fluorine-doped tin oxide (FTO) substrates was achieved through a wet coating process that utilized three different liquid formulations: a dispersion of finely milled WO3 particles, a fully soluble WO3 precursor (acetylated peroxo tungstic acid), and a combination of both (applying a brick-and-mortar strategy). Upon subjecting the WO3 coatings to firing at a temperature of 450 degrees C, it was observed that their properties exhibited marked variations. The fabricated photoanodes are examined using a range of analytical techniques, including profilometry, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and voltammetry. The experimental data suggest that the layers generated through the combination of particulate ink and soluble precursor (referred to as the brick-and-mortar building approach) display advantageous physicochemical properties, rendering them suitable for use as photoanodes in photoelectrochemical cells.
- ItemImpact of various oxidation processes used for removal of sulfamethoxazole on the quality of treated wastewater(KeAi Communications Co., Ltd., 2023-04-17) Tulková, Tereza; Fučík, Jan; Kozáková, Zdenka; Procházková, Petra; Krčma, František; Zlámalová Gargošová, Helena; Mravcová, Ludmila; Sovová, KateřinaThe objective of this research is to describe the impact of different advanced oxidation processes used for the removal of sulfamethoxazole on wastewater quality. Ozone, UV, a combination of ozone and UV, and plasma discharge were employed. Concentrations of sulfamethoxazole were analysed by LC-MS/MS. Chemical and microbiological analyses and ecotoxicological tests were conducted to investigate the quality of treated wastewater. The results of this study show that the most effective technique for the removal of sulfamethoxazole is O3, followed by plasma discharge, O3 + UV and, finally, UV. A significant effect of tested advanced oxidation processes on the chemical composition of wastewater was not observed; however, the number of microorganisms was reduced. In the case of ecotoxicological tests with Lemna minor and crustacean Daphnia magna, a significant negative effect was only observed when plasma was applied.