skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Phenoloxidase-mediated interactions of phenols and anilines with humic materials

Abstract

Phenoloxidases present in terrestrial systems may contribute to the formation of humus through random coupling of a variety of aromatic compounds, including xenobiotic chemicals. Because of their structural similarity to natural substrates originating mainly from lignin decomposition, xenobiotic phenols and anilines can be readily incorporated into the soil organic matter, a phenomenon referred to as binding. The underlying mechanism of binding involves oxidation of the xenobiotic substrates to free radicals or quinone products that subsequently couple directly to humus or to naturally occurring phenols that also are subject to oxidation. The oxidation can be mediated by soil phenoloxidases as well as by abiotic catalysts. The ability of the enzymes to mediate the oxidation was demonstrated in a number of model studies, in which selected pollutants were incubated with humic monomers or natural humic acids in the presence of different phenoloxidases (laccase, peroxidase, tyrosinase). Analysis of the formed complexes by mass spectrometry and {sup 13}C nuclear magnetic resonance (NMR) spectroscopy left no doubt about the formation of covalent bonds between the pollutants and humic materials. Some bonds were formed at the chlorinated sites, leading to partial dehalogenation of the aromatic contaminants. Experimental data indicated that bound phenols and anilines were unlikelymore » to adversely affect the environment; their release from humic complexes by soil microorganisms was very limited and once released, they were subjected to mineralization. For those reasons, phenoloxidases, which proved capable of mediating the underlying reaction, are currently considered as a tool for enhancing immobilization phenomena in soil.« less

Authors:
;
Publication Date:
Research Org.:
Pennsylvania State Univ., University Park, PA (US)
OSTI Identifier:
20082434
Resource Type:
Journal Article
Journal Name:
Journal of Environmental Quality
Additional Journal Information:
Journal Volume: 29; Journal Issue: 3; Conference: Symposium Interaction of Biomolecules with Soils, Annual Meetings of the American Society of Agronomy, Baltimore, MD (US), 10/18/1998--10/22/1998; Other Information: PBD: May-Jun 2000; Journal ID: ISSN 0047-2425
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; SOILS; PHENOLS; ANILINE; HUMUS; SOIL CHEMISTRY; PEROXIDASES; HYDROLASES

Citation Formats

Dec, J., and Bollag, J.M. Phenoloxidase-mediated interactions of phenols and anilines with humic materials. United States: N. p., 2000. Web. doi:10.2134/jeq2000.00472425002900030001x.
Dec, J., & Bollag, J.M. Phenoloxidase-mediated interactions of phenols and anilines with humic materials. United States. doi:10.2134/jeq2000.00472425002900030001x.
Dec, J., and Bollag, J.M. Thu . "Phenoloxidase-mediated interactions of phenols and anilines with humic materials". United States. doi:10.2134/jeq2000.00472425002900030001x.
@article{osti_20082434,
title = {Phenoloxidase-mediated interactions of phenols and anilines with humic materials},
author = {Dec, J. and Bollag, J.M.},
abstractNote = {Phenoloxidases present in terrestrial systems may contribute to the formation of humus through random coupling of a variety of aromatic compounds, including xenobiotic chemicals. Because of their structural similarity to natural substrates originating mainly from lignin decomposition, xenobiotic phenols and anilines can be readily incorporated into the soil organic matter, a phenomenon referred to as binding. The underlying mechanism of binding involves oxidation of the xenobiotic substrates to free radicals or quinone products that subsequently couple directly to humus or to naturally occurring phenols that also are subject to oxidation. The oxidation can be mediated by soil phenoloxidases as well as by abiotic catalysts. The ability of the enzymes to mediate the oxidation was demonstrated in a number of model studies, in which selected pollutants were incubated with humic monomers or natural humic acids in the presence of different phenoloxidases (laccase, peroxidase, tyrosinase). Analysis of the formed complexes by mass spectrometry and {sup 13}C nuclear magnetic resonance (NMR) spectroscopy left no doubt about the formation of covalent bonds between the pollutants and humic materials. Some bonds were formed at the chlorinated sites, leading to partial dehalogenation of the aromatic contaminants. Experimental data indicated that bound phenols and anilines were unlikely to adversely affect the environment; their release from humic complexes by soil microorganisms was very limited and once released, they were subjected to mineralization. For those reasons, phenoloxidases, which proved capable of mediating the underlying reaction, are currently considered as a tool for enhancing immobilization phenomena in soil.},
doi = {10.2134/jeq2000.00472425002900030001x},
journal = {Journal of Environmental Quality},
issn = {0047-2425},
number = 3,
volume = 29,
place = {United States},
year = {2000},
month = {6}
}