Efficiency of Penicillium canescens in Dissipating PAH in Industrial Aged Contaminated Soil Microcosms and Its Impact on Soil Organic Matter and Ecotoxicity

Etienne Veignie,Catherine Rafin

doi:10.3390/pr10030532

Abstract

The filamentous fungus Penicillium canescens, isolated from oil-polluted soil, was evaluated for its ability to dissipate high-molecular-weight polycyclic aromatic hydrocarbons (PAH). The study was conducted in a microcosm containing 180 g of historical PAH-contaminated soil under non-sterile conditions with two incubation temperatures (14 °C and 18 °C) on a 12-h cycle. The experiment was conducted over 8 months, with four experimental conditions created by varying the volumes of the bulking agent and vegetable oil (olive oil) and the time of addition of these compounds. The PAH dissipation performance of the fungal augmentation treatment was compared with that achieved with a biostimulated soil (bulking agent and vegetable oil) and with the untreated soil as control. The greatest PAH dissipation was obtained with P. canescens bioaugmentation (35.71% ± 1.73), with 13 of the 16 US EPA PAH significantly dissipated, at rates above 18%, and particularly high-molecular-weight PAH, composed of more than three fused aromatic rings. Nematode toxicity tests indicated a significant decrease in the toxicity of soil bioaugmented by this fungus. Fulvic and humic contents were significantly increased by this treatment. All these results suggest that bioaugmentation with P. canescens can be used to restore soils with long-term PAH contamination.

Highlights

Polycyclic aromatic hydrocarbons (PAH), produced mainly by anthropogenic activities that use fossil energy sources, such as coal and oil, are widespread pollutants in the environment
The objective of this work was to study the ability of a telluric saprotrophic Ascomycota fungus, Penicillium canescens to dissipate the 16 PAH identified as priority pollutants by the US Environmental Protection Agency (EPA) in industrial aged PAH-contaminated soil microcosms on a laboratory scale
PAH dissipation was assessed after 8 months of incubation in an historical polluted soil with a total PAH contamination of approximately 123.63 mg kg−1 of soil

Summary

Introduction

Polycyclic aromatic hydrocarbons (PAH), produced mainly by anthropogenic activities that use fossil energy sources, such as coal and oil, are widespread pollutants in the environment. They represent a real danger to human health and biotic communities in terrestrial and aquatic ecosystems. Historical industrial activities have resulted in numerous. PAH-polluted soils [2] requiring the development of clean-up techniques. HMW PAH can be strongly bound to soil organic matter (SOM) and form nonextractable residues (NER) [3]. NER strongly sequestered by SOM cannot be degraded by natural soil attenuation and is hazardous when mobilised

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