Widespread Ability of Ligninolytic Fungi to Degrade Hazardous Organic Pollutants as the Basis for the Self-Purification Ability of Natural Ecosystems and for Mycoremediation Technologies

Natalia Pozdnyakova,Ekaterina Dubrovskaya,Svetlana Kuznetsova,Vyacheslav Grinev,Olga Turkovskaya,Sergei Golubev,Elena Sigida,Elena Kryuchkova,Dietmar Schlosser,Giovanna Cristina Varese

doi:10.3390/app12042164

Abstract

The ability of sixteen wood- and soil-inhabiting basidiomycete strains and four ascomycete strains to degrade the most hazardous, widespread, and persistent pollutants (polycyclic aromatic hydrocarbons, oxyethylated nonylphenol, alkylphenol, anthraquinone-type synthetic dyes, and oil) was found. The disappearance of the pollutants, their main metabolites, and some adaptive properties (activities of ligninolytic enzymes, the production of emulsifying compounds and exopolysaccharides) were evaluated. The toxicity of polycyclic aromatic hydrocarbons decreased during degradation. New data were obtained regarding (1) the dependence of the completeness of polycyclic aromatic hydrocarbon degradation on the composition of the ligninolytic enzyme complex; (2) the degradation of neonol AF9-12 by higher fungi (different accessibilities of the oxyethyl chain and the aromatic ring of the molecules to different fungal genera); and (3) the production of an emulsifying agent in response to the presence in the cultivation medium of hydrophobic pollutants as the common property of wood- and soil-inhabiting basidiomycetes and ascomycetes. Promise for use in mycoremediation was shown in the wood-inhabiting basidiomycetes Pleurotus ostreatus f. Florida, Schizophyllum commune, Trametes versicolor MUT 3403, and Trametes versicolor DSM11372; the litter-decomposing basidiomycete Stropharia rugosoannulata; and the ascomycete Cladosporium herbarum. These fungi degrade a wide range of pollutants without accumulation of toxic metabolites and produce ligninolytic enzymes and emulsifying compounds.

Highlights

Environmental contamination by hazardous pollutants is a serious and challenging problem of the present time
Gams IBPPM542, and Fusarium oxysporum IBPPM543 were from the Collection of Rhizosphere Microorganisms (IBPPM RAS, Russia); Trametes hirsuta LE-BIN072, Trametes maxima LE-BIN0275, Trametes ochracea LE-BIN093, Trametes gibbosa LE-BIN1911, Lenzites betulina LE-BIN2047, Pleurotus ostreatus LE-BIN0432, and Steccherinum murashkinskyi LEBIN1963 were from the RAS Federal Research Centre “Fundamentals of Biotechnology” (Moscow, Russia); Trametes versicolor MUT3403, Pleurotus ostreatus MUT2977, Bjerkandera adusta MUT3398, Geotrichum candidum MUT4803, and Cladosporium herbarum MUT3238 were from Mycotheca Universitatis Taurinensis (Turin, Italy); Trametes versicolor DSM11269 and Stropharia rugosoannulata DSM11372 were from Helmholtz Centre for Environmental Research−UFZ (Leipzig, Germany) (Table S1)
We found that the process of degradation of hydrophobic compounds (PAHs, isononylphenol, and oil) by most of the studied fungi was accompanied by the formation of foam, which may serve as an indirect sign of the production of substances with emulsifying activity

Summary

Introduction

Environmental contamination by hazardous pollutants is a serious and challenging problem of the present time. The range of pollutants, which enter the environment as a result of human economic activities and natural processes, is very broad and includes several class of compounds (polycyclic aromatic hydrocarbons (PAHs), synthetic dyes, detergents, chlorinated compounds, pharmaceutical compounds, dioxins, plastics, etc.) and resulting mixtures (creosote, oil, etc.). The discharge and accidental entry of pollutants into the environment is a serious problem, especially when the biodegradation activity of the natural microbiota is insufficient for their removal or neutralization. Natural ecosystems have great detoxification potential, which is ensured by the degradative activity of different organisms. These include basidio- and ascomycetes, some of the most numerous groups of the kingdom of Fungi. The ability of fungi to degrade a wide range of natural compounds and xenobiotics is an important part of the self-purification ability of ecosystems and can be used for the development of ecological biotechnologies [1]

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