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Volume 5, Issue 2 (Suppl) Occup Med Health Aff, an open access journal
ISSN: 2329-6879 Environmental Health 2017
September 7-8, 2017
Page 21
Notes:
conferenceseries.com
September 7-8, 2017 | Paris, France
Environmental Health & Global Climate Change
2nd International Conference on
Natalia Pozdnyakova, Occup Med Health Aff 2017, 5:2(Suppl)
DOI: 10.4172/2329-6879-C1-030
LIGNINOLYTIC FUNGI: THEIR DEGRADATIVE POTENTIAL AND THE PROSPECT FOR
THE DEVELOPMENT OF ENVIRONMENTALLY SIGNIFICANT BIOTECHNOLOGIES
Ligninolytic fungi are taxonomically heterogeneous higher fungi characterized by a unique ability to depolymerizee and
mineralize lignin. They include wood-and soil-inhabiting basidiomycetes and some ascomycetes. The extracellular, non-
specific, and oxidative enzymatic system of these fungi catalyses lignin degradation. This system includes lignin peroxidase,
Mn-peroxidase, versatile peroxidase, and laccase, allowing the degradation of many persistent aromatic compounds with
structures similar to those of the metabolites formed in the biosynthesis or degradation of lignin. Among such compounds are
both individual substances [pesticides, polychlorinated biphenyls, halogenated aromatic compounds, nitro- and amino-sub-
stituted phenols, trinitrotoluene, synthetic dyes and Polycyclic Aromatic Hydrocarbons (PAHs)] and their complex mixtures.
Enzyme synthesis is not repressed when the concentrations of these substances are too low to induce the enzymes. Therefore,
the enzymes can degrade even low concentrations of pollutants. The catalytic action of the Ligninolytic enzymes gives rise to
polar and water-soluble products, which are more accessible for both fungal metabolism and further degradation by the nat-
ural soil micro flora.
On the basis of a screening of basidiomycetes and ascomycetes, we selected the most active fungi for their degradative activity
toward PAHs, nonionic surfactants, alkyl phenols, synthetic dyes, and oil. These fungi were found to hold promise for further
studies and use in biotechnology. Despite some differences, PAH degradation followed the same scheme, first forming quinone
metabolites and later forming phthalic acid, which is included in basal metabolism. All the investigated basidiomycetes and the
ascomycete Cladosporium herbarum completely decolorized anthraquinone dyes, and both the chromophore part of the mole-
cule and the aromatic ring were available for degradation. The site of attack on oxyethylated alkylphenols (the oxyethyl chain or
the aromatic ring) was shown to be determined by the fungal species. The fungi were able to metabolize oil under submerged
cultivation and in soil. Pollutant degradation was accompanied by the production of ligninolytic enzymes and of emulsifiers,
substances that promote pollutant solubility and affect enzyme catalytic activity. The unique properties of Ligninolytic fungi
make them promising for use in bioremediation, particularly if pollutants are difficult to decompose by bacteria.
Biography
Natalia Pozdnyakova is a leading researcher at the Environmental Biotechnology Laboratory of the Institute of Biochemistry and Physiology of Plants and Microorganisms Russian
Academy of Sciences. Her Main research area is Enzymology of the fungal degradation of lignin and xenobiotics.
Natalia Pozdnyakova
Russian Academy of Sciences, Russia