Decrease in Toxicity of Pentachlorophenol and Toluene to Growth of Selected Microbial Consortia and Activated Sludge by Pretreatment with Phanerochaete chrysosporium

The white rot fungus Phanerochaete chrysosporium can degrade toxic compounds under specific nutrient conditions. This attribute was utilized in order to determine the effect of fungal pretreatment on model compounds pentachlorophenol and toluene. The fungal culture was purchased from ATCC, cultured on dextrose agar, and the mycelia harvested to degrade the model compounds. P. chrysosporium was able to degrade up to 74% of initial pentachlorophenol concentration in eight days and up to 31% initial toluene in 31 hours. Specific growth rates of activated sludge and selected microbial consortia were determined on untreated and fungal-pretreated parent model compounds. Specific growth rates for activated sludge and selected microbial consortia were enhanced by fungal pretreatment of both model compounds. Specific growth rates indicated more efficient use of toluene by activated sludge than by toluene-selected microbial consortia, while pentachlorophenol- selected microbial consortia exhibited more favorable growth rates on pentachlorophenol than did activated sludge. Pretreatment results indicated that the toxicity of model compounds was reduced by fungal pretreatment. The growth rates were compared and used as an indication of toxicity reduction which can be exploited at contaminated waste sites or at industrial pretreatment facilities.