Lipases in water-in-ionic liquid microemulsions: Structural and activity studies
Φόρτωση...
Ημερομηνία
Συγγραφείς
Pavlidis, I. V.
Gournis, D.
Papadopoulos, G. K.
Stamatis, H.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Journal of Molecular Catalysis B-Enzymatic
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Water-in-ionic liquid (w/IL) microemulsions formulated with non-ionic surfactants, (Tween 20 or Triton X-100) in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF(6)), were used as media for lipase-catalyzed esterification reactions. The catalytic behavior and stability of lipases from Candida rugosa, Chromobacterium viscosum and Thermomyces lanuginosa in these novel microemulsions were investigated and compared to other microheterogeneous media used so far for enzyme-catalyzed reactions. The catalytic behavior of the enzymes depends strongly on the surfactant concentration and the water content. The dependence of the esterification activity of lipases on molar ratio of water to surfactant (w(o)) follows a bell-shaped profile, presenting a maximum at w(o) approximate to 5. The operational stability of lipases in w/IL microemulsions, especially at high incubation temperature (50 degrees C), was significantly increased compared to that observed in other microheterogeneous media. The highest half-life times (>100 h) were obtained in w/IL microemulsions with low water content. Conformational studies via Fourier transform-infrared (FT-IR) and circular dichroism (CD) spectroscopy indicated that lipases entrapped in w/IL microemulsions in most cases retain their native structure or adapt a more rigid structure compared to other microheterogeneous media, which correlated well with the stability results. A simple procedure suitable for ester separation and enzyme reuse was developed. T lanuginosa lipase retained 90% of activity after ten reaction cycles in w/IL microemulsions formulated with Tween 20. (C) 2009 Elsevier B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
lipase, ionic liquids, microemulsions, stability, ft-ir, circular dichroism, chromobacterium-viscosum lipase, isooctane reverse micelles, secondary structure, circular-dichroism, humicola-lanuginosa, enzymatic-reactions, thermal-stability, organic-solvents, candida-rugosa, media
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000267248700007
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Μηχανικών Επιστήμης Υλικών