Application of Peroxidases in the removal of phenolic compounds: optimization of reaction conditions

GONZALEZ PS,AGOSTINI E, TALANO MA, MILRAD S.

Rosario

Congreso; XLII REUNIÓN ANUAL DE SAIB; 2006

SAIB

Phenolic compounds, present in the drainage from several industries, are harmful pollutants. Here we describe the use of peroxidase isoenzymes from tomato hairy roots, which were able to oxidise phenol and 2,4-dichlorophenol (2,4-DCP) from polluted solutions. We used different enzyme fractions: Total proteins (TP), ionically bound to cell wall proteins (IBP), basic (BP) and acidic peroxidases (AP). We analyzed the optimum conditions, the effects of Polyethyleneglycol (PEG-3350) on the removal and on the enzyme activities to obtain the maximum efficiency in the process. The optimal H2O2 concentration for 2,4-DCP and phenol removal were 1 and 0.1 mM respectively. The addition of PEG (10-100 mg/l) to solutions containing 2,4-DCP showed no effect either on the removal efficiency or on the enzyme activity. However, PEG (100 mg/l) increased the removal efficiency of phenol by BP and IBP. Also, peroxidase activities from BP and IBP were 3 and 13 times higher, respectively, than those detected for the same fractions in solutions without PEG. Peroxidase activities from AP and TP fractions were no affected by PEG. As IBP and BP fractions contained the isoenzymes mainly involved in removal of phenol, the protective effect of PEG, which depends on the contaminant as well as of the enzyme fraction used, would be important to improve the removal efficiency with these isoenzymes.