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Identifier

000430980

Title

Ανάπτυξη και βελτιστοποίηση βιοδιεργασιών καταλυόμενων από τρανσαμινάσες για τη σύνθεση δομικών λίθων φουρανικών πολυμερών

Alternative Title

Development and optimization of bio-processes catalyzed by transaminases for the synthesis of building blocks for furane polymers.

Author

Κελεφιώτης Στρατηδάκης, Παναγιώτης Δ.

Thesis advisor

Παυλίδης, Ιωάννης

Reviewer

Γανωτάκης, Δημήτριος
Σμόνου, Ιουλία

Abstract

Αim of this Master's Thesis was the amination of furanoid compounds for the production of polyamide and polyimine biopolymers. The furoanoid compounds which were used in this project can be produced by enzymatic or chemical treatment of by-products of agricultural processes, following the principles of circular economy. Initially, the catalytic activity of 17 recombinant transaminases from laboratory’s toolbox was investigated towards the thermodynamically favored deamination reaction of furfurylamine and 5-methylfurfurylamine in two pH (7.5 and 9.0), while the deamination of 1-phenylethylamine was investigated as a benchmark substrate. Transaminases from Vibrio fluvialis, Rhodobacter sphaeroides, Chromobacterium violaceum and Ruegeria pomeroyi gave the most promising results. Preliminary results on the processes of interest, transaminases from R. sphaeroides and R. pomeroyi were excluded from further studies, owe to instability issues and low productivity, respectively. Thus, the next experiments were performed with the transaminases from V. fluvialis and C. violaceum. The selected enzymes were purified, using affinity chromatography before applied to desired reactions. For the polyimide polymer, furan-2,5- dicarvaldehyde was selected, while for the polyamide the 5-formyl-2-furancarboxylic acid, after the amination. Dicarvaldehyde’s amination leads to spontaneous polymer formation, possibly due to Schiff base formation at the alkaline reaction conditions. This polymer was analyzed by Scanning Electron Microscopy (SEM) as well as by Fourier Transform Infrared Spectroscopy (FTIR). 5-Formyl-2-furancarboxylic acid is also aminated efficiently from both transaminases, thus a optimization of reaction conditions was performed. It was found that the optimal reaction conditions with isopropylamine as amine donor was pH 9.0 and 400 mM isopropylamine, conditions under which the reaction is completed with 100 % conversion under 30 min. In conclusion, the bioprocesses developed in this work can lead to the synthesis of innovative biopolymers.

Language

Greek

Subject

Biocatalysis

Biopolymers

Chromobacterium violaceum

Circular Economy

Furan

Isopropylamine

Vibrio fluvialis

Βιοκατάλυση

Βιοπολυμερή