Národní úložiště šedé literatury Nalezeno 2 záznamů.  Hledání trvalo 0.00 vteřin. 
Study on production of polyhydroxyalkanoates by psychrophilic bacteria
Šlosárová, Katarína ; Sedlář, Karel (oponent) ; Pernicová, Iva (vedoucí práce)
Bacteria produce polyhydroxyalkanoates (PHA) as intracellular storage of carbon and energy. From a technological point of view, they have great potential as biodegradable versions of conventional plastics. However, their main disadvantage compared to them is the high cost of production. Research is therefore focusing on ways to overcome this obstacle, one of which is the use of strains of extremophilic micro-organisms. However, the amount of research on psychrophiles is lower compared to other types of extremophiles. Here, the results of the first screening involving 78 cold-adapted bacterial strains isolated from East Antarctica are presented. Both genotypic and phenotypic methods were used for the selection of potential PHA producers. The polymerase chain reaction mainly demonstrated the presence of genes encoding PHA synthases, namely PHA synthases class I and II. Staining with Nile Red and Sudan Black B, as a typical initial screening method from the phenotypic level, did not provide indicative results for psychrophiles and/or psychrotolerants. In this work, FTIR spectroscopy in combination with a high-throughput microculture system (Duetz-MTPS) was used to explore the presence of PHA, which was later confirmed by gas chromatography. Cultivation was conducted on five different media. Based on all the results the highest biomass production and PHA accumulation showed Pseudomonas sp. belonging to the green snow isolates. Interestingly, a high synthesis of PHA, specifically P(3HB), was observed on complex BHI medium with extra glucose addition, which did not provide the nitrogen limitation that is typical for the stimulation of the PHA synthesis and accumulation. It can be assessed that the presence of promising producers among polar bacteria was confirmed and the yield of PHA can be further increased by optimizing the media composition and growth conditions.
Development and optimization of methods for detection of selected fruit species in foodstuffs
Šlosárová, Katarína ; Wikarská, Monika (oponent) ; Fialová, Lenka (vedoucí práce)
Various types of adulteration of food products are becoming more frequent in the food industry than ever. That is no different for fruit products. This bachelor thesis deals with the detection of mango in fruit purées for infants through the use of qPCR and HPLC in three selected commercial products and their prepared replicas. Within the framework of molecular biology, different primers specific for mango were tested. Several primers, which were the most suitable for the demonstration of mango in fruit purées, were selected based on the course of the qPCR reaction, the size of the amplified product, specificity, and sensitivity. Using these primers, the presence of mango was proven in all six analysed samples. Regarding the instrumental part of the work, a rapid and simple method of extraction of phenolic compounds for their analysis by HPLC was tested, which has been previously successfully used on another plant matrix. This method was proved to be unsuitable for the extraction of phenolic compounds from fruit purées for the purpose of their authenticity verification using HPLC [1].

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