Ανάπτυξη βιοκαταλυτικών διεργασιών σε μη συμβατικά μέσα για την τροποποίηση ενώσεων φυτικής προέλευσης με στόχο την αναβάθμιση των ιδιοτήτων τους

• Published in: Journal of Food Science
• Main Authors: Tzialla, Aikaterini, Τζιάλλα, Αικατερίνη
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: University of Ioannina 2009
• Subjects: Βιοκατάλυση; Λιπάσες; Ένζυμα; Ακινητοποίηση; Μαστίχα Χίου; Βιομετατροπές; Πράσινες διεργασίες; Λακκάσες; Biocatalysis; Lipases (CRL); Enzymes; Immobilization; Mastic gum; Biotransformations; Green process; Laccases; Φυσικές Επιστήμες; Βιολογία; Επιστήμες Μηχανικού και Τεχνολογία; Βιομηχανική Βιοτεχνολογία; Natural Sciences; Biological Sciences; Engineering and Technology; Industrial Biotechnology; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10442/hedi/27568; https://doi.org/10.12681/eadd/27568

In the present PhD thesis, it was studied the development of biocatalytic process for the modification of main constitutes of mastic oil, with ultimate target the increasement of their biological action. For this purpose, it was investigated the biotransformation of the essential oil and its main constitutes such as α-pinene and d-limonene, with the use of enzymes such as chloroperoxidase from the fungus Caldariomyces fumago (CPO) and laccases from the fungus Trametes versicolor (TvL), Trametes hirsuta (ThL) and Botrytis cinerea (BcL), as well as with the use of hydrolytic enzymes such as lipase B from Candida antarctica (CaLB), in non conventional media. These enzymes were used either in free form or immobilized on solid supports. The enzymatic biotransformation of the hydrophobics monoterepenes were examined in non conventional media with low water content (microemulsions, ternary systems, organic media) which are formed with main constitutes of mastic oil (α-pinene, d-limonene). With the aim to maximize the catalytic performance of chloroperoxidase from Caldariomyces fumago (CPO) in surfactant free ternary systems, the influence of the composition and the hydration state of the system, the nature of the oxidizing agent as well as substrate availability on the catalytic behavior and stability of the enzyme was investigated, using the chlorination of monochlorodimedone (MCD) and the epoxidation of styrene as model reactions. It was concluded that in low water systems formulated with α-pinene CPO stability is significantly increased compared to other reaction media (up to 65% residual activity after 24 h of incubation at 30°C). The increased stability was in accordance with differential scanning calorimetry (DSC) findings. Electron paramagnetic resonance (EPR) spectroscopy indicated that in low water content systems the ferric environment of the active site of CPO does not undergo severe modifications. The kinetic analysis in all cases followed the Michaelis-Menten kinetic and the results revealed that the ...