Potential use of peroxidases for 2,4-dichlorophenol bioremediation

ANGELINI, VANINA; TALANO, MELINA; GONZÁLEZ PAOLA; AGOSTINI ELIZABETH; MILRAD SILVIA

Huerta Grande

Congreso; Presentación I Reunión conjunta de Sociedades de Biología de la República Argentina; 2007

Sociedad de Biología de Córdoba

POTENTIAL USE OF PEROXIDASES FOR 2,4-dichlorophenol BIOREMEDIATION   Angelini V.A., Talano M., González P.S., Agostini E., Milrad S. Dpto Biología Molecular. FCEFQyN. UNRC. Río Cuarto. Córdoba. aangelini@exa.unrc.edu.ar  Peroxidases (Px) are enzymes that have been applied in the removal of phenolic compounds like 2,4-dichlorophenol (2,4-DCP), which is a highly toxic environmental pollutant. The aim of this study was to perform a biochemical characterization and a kinetic study of 2,4-DCP removal by using different fraction of Px, obtained from tobacco wild type (wt) and transgenic hairy roots which express two basic Px from tomato (TPX1 and TPX2). The different Px fractions (total crude extract (TCE), soluble Px (SP) and ionically bound to cell wall Px (IBP)) were obtained using buffers with low and high ionic strength. The Px were analyzed by isoelectric focusing and the zymograms showed the presence of different basic, neutral and acidic isoenzymes. The optimal conditions for 2,4-DCP removal were established for each fraction of Px. The optimal pH for the activity of Px groups obtained from tobacco wt hairy roots was 6 while for transgenic hairy roots the  optimal pH was 7. The optimal H202  concentration was 0.2 mM. The Px present in TCE and IBP of the transgenic hairy roots, showed lower values of Km and Vmax than those from wt hairy root extracts. These kinetics parameters were similar for the SP from wt and transgenic hairy roots. The higher catalytic efficiency was obtained for IBP fraction of transgenic hairy roots. IBP fraction could be used for bioremediation of 2,4-DCP from aqueous solutions