EFFECTS OF P-CRESOL AND CHLOROPHENOLS ON PENTACHLOROPHENOL BIODEGRADATION

The effects of three aromatic compounds, p-cresol, 2,4-dichlorophenol (DCP), and 2,4,6-trichlorophenoI (TCP), on cell growth and pentachloro phenol (PCP) degradation by a Flavobacterium species were investigated . While p-cresol was not degraded by this bacterium, DCP and TCP were simultaneously degraded with PCP. Both DCP and TCP lowered cell growth and PCP degradation rate. Cell growth was modeled by cell death, beca use p-cresol, DCP, and TCP were toxic to the organism. A new model was used to predict cell death rate in a mixture of two toxic compounds f rom the cell death kinetics for each individual compound. PCP degradat ion rates were modeled by conventional inhibition models, but only ove r a small concentration range for the secondary toxic compound. Howeve r, a new empirical model described PCP degradation over a wider concen tration range of the secondary toxic compound. (C) 1995 John Wiley and Sons, Inc.