Bioremediation of a Chilean Andisol contaminated with pentachlorophenol (PCP) by solid substrate cultures of white-rot fungi

Abstract

This study provides a first attempt investigation of a serie of studies on the ability of Anthracophyllum discolor, a recently isolated white-rot fungus from forest of southern Chile, for the treatment of soil contaminated with pentachlorophenol (PCP) to future research on potential applications in bioremediation process. Bioremediation of soil contaminated with PCP (250 and 350 mg kg⁻¹ soil) was investigated with A. discolor and compared with the reference strain Phanerochaete chrysosporium. Both strains were incorporated as free and immobilized in wheat grains, a lignocellulosic material previously selected among wheat straw, wheat grains and wood chips through the growth and colonization of A. discolor. Wheat grains showed a higher growth and colonization of A. discolor, increasing the production of manganese peroxidase (MnP) activity. Moreover, the application of white-rot fungi immobilized in wheat grains to the contaminated soil favored the fungus spread. In turn, with both fungal strains and at the two PCP concentrations a high PCP removal (70-85%) occurred as respect to that measured with the fungus as free mycelium (30-45%). Additionally, the use of wheat grains in soil allowed the proliferation of microorganisms PCP decomposers, showing a synergistic effect with A. discolor and P. chrysosporium and increasing the PCP removal in the soil.

Biosurfactants are useful tools for the bioremediation of contaminated soil: a review

“…White-rot fungi have the ability to degrade a wide range of persistent or toxic environmental contaminants, such as PCBs, PAHs, pentachlorophenol, pesticides, dioxins, and synthetic dyes, among others, which makes them good candidates for use in processes of bioremediation (Barr and Aust, 1994;Pointing, 2001;Eichlerová et al, 2005;Tortella et al, 2005;Ru-bilar et al, 2008;Rubilar et al, 2011). The potential of white-rot fungi resides in their enzymatic system, which is nonspecific, and secreted into the extracellular environment (Durán and Esposito, 2000).…”

“…Several strategies involving biological, physicochemical, and thermal processes have been developed to remediate contaminated sites (Bollag and Bollag, 1995;Vidali, 2001;Rubilar et al, 2011). Methods such as incineration, excavation, landfilling and storage are expensive, sometimes difficult to execute (Vidali, 2001;Jain et al, 2005), inefficient, and often exchange one problem for another (Bollag and Bollag, 1995).…”

The ways to increase efficiency of soil bioremediation

“…Rubilar et al [36] investigated the ability of white rot fungi (Anthracophyllum discolour and Phanerochaete chrysosporium) to degrade pentachlorophenol to give the best results for the tested consortia of fungi immobilized on wheat grains as lignincellulose material. The test fungi were characterized by rapid growth and high production of lignin degradating enzymes, such as manganese peroxidase and lignin peroxidase, and the effective degradation of contaminants [37].…”

“…The increase in the amount of toxic compounds and insufficient rate of microorganisms growth in the environment often causes that the microorganisms do not have the ability to develop so many metabolic pathways for the degradation of pollutants [36]. Therefore, it seems reasonable to use in bioremediation processes not only metabolic potential of microorganisms, but also their enzymes in the form of preparations.…”

“…According to Rubilar et al [36], many fungal species are considered to be suitable for the removal of chlorinated phenolic compounds from the contaminated environments. The activity of fungi is mainly due to the action of extracellular oxidoreductases, like laccase, manganese peroxidase, and lignin peroxidase, which are released from fungal mycelium into their nearby environment.…”