ΠΜΣ Μικροβιακή ΒιοτεχνολογίαLibrary of the School of Science
Αμαλία Καραγκούνη Καθηγήτρια, Γιώργος Διαλλινάς Καθηγητής, Δημήτρης Χατζινικολάου Επίκ. Καθηγητής (Επιβλέπων)
"Ετερόλογη έκφραση και χαρακτηρισμός μίας λακκάσης του θερμόφιλου μύκητα Myceliopthora thermophila - χρήση της σε εφαρμογές βιοτεχνολογικού ενδιαφέροντος"
"Heterologous expression and characterization of a laccase of the thermophilic fungus Myceliopthora thermophila - use in applications of biotechnological interest"
Laccases (EC 184.108.40.206) are multicopper enzymes that catalyze the oxidation of a
variety of phenolic compounds, with concomitant reduction of O2 to H2O. Their
unique characteristics such as high chemical stability, the ability to catalyze
both anabolic and catabolic procedures and the ecological nature of the
reaction make them extremely useful tools for biotechnology applications.
Myceliopthora thermophila is a thermophilic fungus capable of degrading
cellulosic biomass at high speeds. This fungus produces a variety of enzymes
such as endoglucanases, exoglucanases, laccases, xylanases, enzymes that are
used in various industrial applications. In the present study, a laccase from
Myceliopthora thermophila was heterologously expressed in the methylotrophic
yeast Pichia pastoris. The selected gene had a total size of 2093 bp and was
organized in 3 exons (258,1498,197 bp) interrupted by 2 introns (58 and 82 bp).
The removal of the interfering sequences was achieved using the overlapping PCR
technique. The gene was then inserted into a specific vector and was
heterologously expressed in Pichia pastoris. The isolated protein from the
heterologous expression was tested for the ability to oxidize ABTS and the
ability to oxidize ascorbic acid. For the biotechnological use of laccases, an
industrially available laccase from Myceliopthora thermophila was used to
polymerize a variety of aromatic compounds. A variety of factors affecting the
reaction were tested such as the enzyme-substrate ratio, the temperature, pH
and time of the reaction. The evaluation of the isolated polymers was examined
using ultraviolet-visible (UV-vis) spectrums and infrared (FT-IR) spectrums.
Myceliopthora thermophila, Heterologous expression, Overlapping PCR, Laccases, Polymerization of aromatic compounds