Μηχανιστική ενζυμολογία: εφαρμογές στην παραγωγή βιοκαυσίμου

• Main Authors: Foukis, Athanasios, Φούκης, Αθανάσιος
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: University of Ioannina 2017
• Subjects: Βιοκαύσιμα; Υδρολάσες; Βελτιστοποίηση διαδικασιών; ΚΜ-IFO-0288-Α; CALB; LipA; Ενζυμικά καταλυόμενη εστεροποίηση; Μηχανισμός δράσης; Biofuel; Hydrolases; Process optimization; Enzyme catalyzed esterification; Mechanism of action; Φυσικές Επιστήμες; Χημεία; Επιστήμες Μηχανικού και Τεχνολογία; Περιβαλλοντική Βιοτεχνολογία; Natural Sciences; Chemical Sciences; Engineering and Technology; Environmental Biotechnology; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10442/hedi/41857; https://doi.org/10.12681/eadd/41857

Biofuels are the most favorable alternative source of fuels. Thus, the aim of this thesis was to study the reactions and mechanisms of enzymatic esterification by hydrolases (KM-IFO-0288-A, CALB, LipA), targeting to the production of biofuel through esterification reactions of fatty acids derived from the oxygenation of residues from the beverage industries (Mixture A) with ethanol and 1-butanol at high yields and ester concentrations so that to make this production economically viable and sustainable with the ultimate goal of gradual self-sufficiency from fossil fuels. In order to achieve the above objectives, protocols of kinetic methodologies were employed, such as proton inventories (P.I.), calculation of the solvent isotope effect (S.I.E.) and kinetic isotope effect (K.I.E.), response surface methodology (RSM), and multi criteria decision analysis (MCDA).Consequently, for the KM-IFO-0288-A protease a full characterization was performed based on a new experimental sequence (P.I., pH and absolute temperature profiles in systems of increasing ionic strength, as well as P.I. in a broad pH range where the used hydrolase was active) in order to further investigate its mechanism and appropriateness for use in non-conventional reaction media. Then, immobilization of the KM-IFO-0288-A protease was achieved, followed by esterification reactions with Mixture A and ethanol, in anhydrous solvent-free reaction environment targeting to biofuel production catalyzed by KM-IFO-0288-A protease.Subsequently and by using the enzymes, immobilized lipase B, from Candida antarctica (CALB), and immobilized lipase A, from B. subtilis (LipA), a series of esterifications of Mixture A were performed with ethanol and 1-butanol, in anhydrous n-hexane as solvent. Throughout these esterification reactions the following were applied: (a) the methodology of response surfaces to optimize the responses in % yield and the total ester concentration, in the esterification reaction mixture, and (b) the total solution of each operated experimental ...