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The effect of nonylphenol on fungi following the application of contaminated sewage sludge on agricultural soil was studied in laboratory experiments. Nonylphenol bioavailability and adsorption were determined in the soil alone and soil–sludge mixtures. Mixing the soil with sludge made it possible to measure the nonylphenol concentration in the soil solution, which comprised between 6.6 × 10−6and 3.8 × 10−7M, according to the sludge. We then examined the dose–response relationship between nonylphenol concentration in the culture medium and both biomass production and germination rate of the spores from several strains of filamentous fungi. When applied in this range of concentration, nonylphenol was without noticeable short‐term effect on these endpoints. Long‐term exposure of fungi to nonylphenol was also assessed. The most intensive effect was a strong stimulation of spore production and germination in Fusarium oxysporumSchlechtendahl. Biomass production by the Fusariumstrains also increased. Finally, nonylphenol was shown to induce laccase production in Trametes versicolorWe conclude that the potential of nonylphenol to adversely affect several soil fungi remains low.

AbstractSolid carriers have been developed to inoculate Trametes versicolorand Cunninghamella elegansinto 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−1PAHs. Fungal biomass and activity of extracellular laccases, enzymes produced by T. versicoloras markers of metabolic activity in the contaminated soil, both decreased after 2 weeks of incubation. Supplementing the soil with a mixture of carbon, nitrogen and phosphorus enhanced the fungal activity period. A 38% decrease of solvent extractable PAHs was observed in manufactured gas plant site soils when supplemented with T. versicolor, Glucidex 19TM, ammonium nitrate, lime phosphate and Montanox 80TM, after 20 weeks. Then, the degradation proceeded more slowly during the following 30 weeks, and reached 43% of initial extractable PAHs. Some factors governing a limited PAH biotransformation in the soil are discussed.

The surface run-off of a number of pesticides (diuron, isoproturon, atrazine, alachlor, aclonifen, trifluralin, lindane and simazine), chosen for their range of adsorption behaviours, was studied using simulated rainfall applied to small plots over a short time (one hour). Pesticides were applied together onto bare soil using two different sandy loam soils from Jaillière and Coet Dan sites. The surface run-off samples were collected throughout the running of the event and concentrations of pesticides were measured in both liquid and solid phases. Sorption isotherms for isoproturon and diuron on Jaillière soil as well as eroded particles were measured under equilibrium conditions and compared to their partitioning during surface run-off. At the rainfall intensity used, both soils generated a large load of eroded particles. The average run-off flow rate increased with time for the Jalliére soil, while it remained relatively constant at a higher level for the Coet Dan soil. The concentrations of each pesticide in the run-off samples decreased as the experiments proceeded. The pesticides were classified into two types by their partitioning between the solid and liquid phases. Atrazine, simazine, diuron, isoproturon and alachlor were mainly transported in surface run-off water. By contrast, 90% of trifluralin and aclonifen was adsorbed onto eroded particles. Lindane was intermediate, with a 37% adsorption level. When the contribution of eroded particles was minor, the agrochemical concentrations were inversely proportional to the water flow rate. We have proposed a model that describes the mass of chemicals extracted from soil into surface water during a surface run-off event of a given average duration and flow rate. This model takes into account the dilution of the soil solution and the desorption of chemicals through two parameters called, respectively, the dilution factor and the extraction retardation factor. The desorption kinetic was the limiting step in the surface run-off of weakly sorbed chemicals, such as isoproturon. © 1999 Society of Chemical Industry

The ability of the white rot basidiomycete Phanerochaete chrysosporium to transform s-triazine herbicides has been investigated in laboratory experiments. The chlorinated metabolites formed during atrazine N-dealkylations were not further transformed by the fungus, whereas hydroxy-atrazine was converted to an unknown product. P. chrysosporium was also able to carry out the N-dealkylation of the herbicides simazine, propazine and terbuthylazine. Herbicide metabolism was not supported by purified peroxidases. The highest rates of herbicide N-dealkylation were obtained in liquid cultures maintained under moderate temperature allowing a long mycelium growing phase. Atrazine transformation was found to be supported by the mycelium, which contained significant amounts of microsomal cytochrome P450. Herbicide N-dealkylation was decreased in the presence of 1-aminobenzotriazole, in agreement with the involvement of P450 monooxygenases in atrazine metabolism. © 1997 SCI.

The biodegradation of phenanthrene and benzo[a]pyrene was assayed in liquid and wet sand cultures in the presence of five filamentous fungi. In the controls, 85% volatilisation of phenanthrene occurred within 28 days in liquid cultures while it was only 50% in wet sand. In the later system, remaining phenanthrene and benzo[a]pyrene amounted to 6–51 and 53–92% of their initial levels, respectively, according to the strains. Then, wet sand used as a screening tool evidenced Trametes versicolor and Cunninghamella elegans as the most efficient polycyclic aromatic hydrocarbons degraders among ten strains. © Rapid Science Ltd. 1998 [ABSTRACT FROM AUTHOR]