Environmental Engineering Reference
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1 nmol/mg protein/min in contaminated soil. The specific activity of enzyme in
root control was 5.3 × 10 −3 U/mg protein while it was 3.5 × 10 −3 U/mg protein in
contaminated roots. The specific activity of enzyme in shoots was 1.8 × 10 −3 and
1.7 × 10 −3 U/mg protein in control and contaminated soil respectively. Our results
propose that in the root grown in contaminated soil, the plant uses peroxidase iso-
form in comparison with control roots, while in the shoots the same peroxidase was
used in the plant in both contaminated and control.
Keywords Festuca arundinacea · Light crude oil · Peroxidase · Enzyme · Pollution
1 Introduction
Peroxidases are a group of enzymes that catalyze oxidation-reduction reactions.
As such, they are classified as oxido-reductases. They are a group of enzymes that
occur especially in plant cells and catalyze the oxidation of a substance by perox-
ide. Peroxidase can be used for treatment of industrial waste waters. For example,
phenols, which are important pollutants, can be removed by enzyme-catalyzed po-
lymerization using horseradish peroxidase. Thus, phenols are oxidized to phenoxy
radicals, which participate in reactions producing polymers and oligomers that are
less toxic than phenols. A number of reviews have addressed the structural and
catalytic properties of the various peroxidase isoforms in general (Hofmann et al.
2002 ; Wood et al. 2003 ) and specifically in plants (Dietz et al. 2002 ). Experimental
evidence exists for a triple peroxidase function in plant cell biology as (1) anti-
oxidant, (2) modulator of cell signaling pathways, and (3) redox sensor. In 1996,
cDNA sequences encoding a barley 1-Cys peroxidase (Stacy et al. 1996 ) and a
2-Cys peroxidase were published and identified as peroxidase. Contamination of
soil by crude oil and its byproducts cause changes in physico-chemical and bio-
logical properties of soil. Depending on chemical composition and concentration,
the oil influences on soil enzymatic and microbiological activity. Crude oil and its
by-products are widely used by human for various reasons, including home heat-
ing and fueling of vehicles. During the past century, the use of petroleum products
increased; this has resulted in the contamination of soil and water by petroleum and
its by-products. The spilling of crude oil into the soil causes damages to the environ-
ment and changes the biological and physico-chemical properties of the soil. Some
petroleum components are toxic for living organisms, however, some plants and
microorganisms are able to biodegrade the crude oil hydrocarbons into products
less toxic than the parent compounds (Cerniglia 1992 ). In this study, the effect of
oil-contaminated soil on the activity of peroxidase was studied and compared with
control (non-contaminated soil).
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