Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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  • Master Thesis
    Chemical Characterization of Caldanaerobacter Subterraneus Subsp. Tengcongensis Heme-Nitric Oxide/Oxygen Binding Protein
    (01. Izmir Institute of Technology, 2020) Erdal, Merve; Sürmeli, Nur Başak; Sürmeli, Nur Başak
    Hemoproteins, which contain the heme prosthetic group , take part in different biological processes in many stages of life. Their ability to catalyze important biosynthesis reactions makes them good candidates for understanding and elucidating complex mechanisms for biocatalysis. In this study, the catalytic properties of thermophilic Thermoanaerobacter tencogensis nitric oxide/oxygen binding protein, a heme protein reshaped by rational design, were investigated and chemical characterization was carried out. The peroxidase activity of the enzyme was investigated by the oxidation reactions of guaiacol, amplex red and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS). Kinetic parameters of the reactions were determined. These obtained results demonstrated that, in the presence of H2O2, wild type and Y140H TtH-NOX proteins are able to catalyze oxidation reactions of guaiacol, Amplex red and ABTS. Comparison of the kinetic parameters showed that Y140H mutant catalyzed the guaiacol and ABTS oxidation 3-fold and 15 -fold faster than wild type enzyme, respectively. The stability of TtH-NOX proteins were investigated in the presence of organic solvents. Results were demonstrated that WT TtH-NOX was more stable than Y140H mutant in the presence of organic solvents In addition to these, for the first time, thermophilic TtH-NOX proteins were immobilized with a novel enzyme immobilization method and organic-inorganic hybrid nanostrucrures were obtained. Copper ion incorporated TtH-NOX-based hybrid nanoflowers were synthesized at different pH values. SEM and EDX analysis of TtH-NOX-based hybrid nanoflowers proved that free TtH-NOXs were immobilized successfully.
  • Master Thesis
    Chemical Characterization of Olive Oils From Karaburun Peninsula
    (Izmir Institute of Technology, 2014) Uncu, Oğuz; Özen, Fatma Banu
    Chemical characteristics of olive oils produced from Erkence olive variety that is mainly grown around Karaburun Peninsula of İzmir have not been investigated thoroughly although this variety has high oil content and ripens earlier compared to other olive types. Identifying the chemical characteristics of olive oils could be useful to obtain geographical indication labelling for olive oils produced from this variety. Aim of this study is to determine some important chemical characteristics of olive oils from Erkence olive variety produced in Karaburun region and to investigate the differences in olive oils that come from various parts of the Peninsula using chemometric techniques as principal component analysis (PCA) and partial least square (PLS) regression. For this purpose, total phenolic content, fatty acid profile, phenolic profile, total carotene and chlorophyll contents and oxidative stability of 64 olive oils were determined. FTIR spectra for these oils were also evaluated. According to PCA results, classification with respect to geographical origin was relatively more successful with FTIR analysis while phenolic and fatty acid profiles did not result very satisfactory separation between regions. Moreover, FTIR spectra and various chemical parameters were used to predict oxidative stability of all olive oil samples. Oxidative stability was predicted successfully from IR spectra whereas prediction from chemical parameters was not that successful. IR spectra were also used to predict various chemical parameters. As a result of PLS regression; chlorophyll and carotenoid, some individual phenolic components (pcoumaric, hydroxtyrosol) and some major fatty acids (oleic, linoleic and palmitic) were predicted.