Comparison of the removal of 2,4-dichlorophenol and phenol from polluted water, by peroxidases from tomato hairy roots, and protective effect of polyethylene glycol

• Published in: Chemosphere (Oxford) Vol. 70; no. 6; pp. 982 - 989
• Main Authors: González, Paola Solange, Agostini, Elizabeth, Milrad, Silvia Raquel
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2008; Elsevier
• Subjects: 2,4-D; acidic peroxidase; Additives; Applied sciences; basic peroxidase; biodegradation; Biological and medical sciences; Biological and physicochemical phenomena; Biological treatment of waters; Bioremediation; Biotechnology; Chlorophenols - isolation & purification; Chlorophenols - metabolism; Environment and pollution; Enzyme Activation - drug effects; enzyme activity; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General purification processes; genetic transformation; Hairy roots; hydrogen peroxide; Industrial applications and implications. Economical aspects; ionically bound to cell wall peroxidase; Isoenzymes - metabolism; Lycopersicon esculentum; Natural water pollution; PEG; peroxidase; Peroxidase - metabolism; Peroxidase isoenzymes; phenol; Phenol - isolation & purification; Phenol - metabolism; Phenolic compounds; phytoremediation; Plant Proteins - metabolism; Plant Roots - enzymology; Pollution; polyethylene glycol; Polyethylene Glycols - pharmacology; Rhizobium rhizogenes; roots; Solanum lycopersicum var. lycopersicum; tomatoes; transgenic plants; wastewater treatment; Wastewaters; Water Pollutants, Chemical - isolation & purification; Water Pollution, Chemical - prevention & control; Water treatment and pollution; Peroxidase isoenzymes; Additives; PEG; Bioremediation; Phenolic compounds; Hairy roots; Hairy root; Isozyme; Enzymatic catalysis; Biological purification; Ethylene oxide polymer; Additive; Decontamination; Dicotyledones; Angiospermae; Lycopersicon esculentum; Peroxidase; Solanaceae; Organic compounds; Enzyme; Polymerization; Organic chlorine compounds; Operating conditions; Phytoremediation; Peroxidases; Plant origin; Phenols; Spermatophyta; Water pollution; Oxidoreductases; Waste water purification
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2007.08.025

Multiple efforts have been directed towards optimized processes in which enzymes, like peroxidases, are used to remove phenolic compounds from polluted wastewater. Here we describe the use of peroxidase isoenzymes from tomato hairy roots, which were able to oxidise 2,4-dichlorophenol (2,4-DCP) and phenol from aqueous solutions. This could be an interesting alternative for the removal of these compounds from contaminated sites. We used different enzyme fractions: total peroxidases (TP), ionically bound to cell wall peroxidases (IBP), basic (BP) and acidic peroxidases (AP). We analyzed the optimum conditions of removal, the effect of Polyethyleneglycol (PEG-3350) on the process and on the enzyme activities, to obtain the maximum efficiency. The optimal H
2O
2 concentrations for 2,4-DCP and phenol removal were 1 and 0.1
mM, respectively. TP, IBP and BP showed better removal efficiencies than AP, for both contaminants. The addition of different concentrations (10–100
mg
l
−1) of PEG-3350 to solutions containing 2,4-DCP showed no effect on the removal efficiencies of the isoenzymes. However, PEG (100
mg
l
−1) increased the removal efficiency of phenol by BP and IBP fractions. On the other hand, peroxidase activities from BP and IBP fractions were 3 and 13 times higher, respectively, than those detected for the same fractions in phenol treated solutions without PEG. 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 of phenol by some peroxidase isoenzymes.