Inoculation of filamentous fungi in manufactured gas plant site soils and PAH transformation

Solid carriers have been developed to inoculate Trametes versicolor and Cun ninghamella elegans into manufactured gas plant site soils. Pelleted wheat bran carriers were very efficient in stimulating the growth of fungi in an industrial soil containing about 2800 mg kg(-1) PAHs. Fungal biomass and ac tivity of extracellular laccases, enzymes produced by T. versicolor as mark ers of metabolic activity in the contaminated soil, both decreased after 2 weeks of incubation. Supplementing the soil with a mixture of carbon, nitro gen and phosphorus enhanced the fungal activity period. A 38% decrease of s olvent extractable PAHs was observed in manufactured gas plant site soils w hen supplemented with T. versicolor, Glucidex 19(TM), ammonium nitrate, lim e phosphate and Montanox 80(TM), after 20 weeks. Then, the degradation proc eeded more slowly during the following 30 weeks, and reached 43% of initial extractable PAHs. Some factors governing a limited PAH biotransformation i n the soil are discussed.