The toxic effect of solvent on the biological degradation of pentachlorophenol and pentachloronitrobenzene by white rot fungus

The chemically rather inert and potential pollutants, PCP (pentachlorophenol) and PCNB (pentachloronitrobenzene), are used in large quantities as fungicides. The chlorinated ring structure tends to increase their stability. In order to minimize their long-term residual effectiveness, a study was made on determination of their biological degradation rates and respective conditions thereof. White rot fungi (Phanerochaete chrysosporium) was used in a culture medium adjusted to pH 5 and containing basic nutrients and tracing items. PCP and PCNB dissolved in acetone and the fungus were added in desired amounts to 50 ml of culture medium in Erlenmeyer flasks and incubated at 35 degree C. In order to investigate and compare the biodegradation effects of the solvent utilized, up to a 10-fold volume was used. After 21 days of incubation, the solvent used inhibited the biological degradation of PCP and PCNB dramatically and, accordingly, decreased the amount of the formation of biomass.