Inefficiency of Mycobacterium chlorophenolicum PCP-1 to enhance mineralization of pentachlorophenol in soil microcosms

We examined the mineralization of pentachlorophenol (PCP) in sterile and no n-sterile soil with or without added bacteria (Mycobacterium chlorophenolic um PCP-1). The soil used had no history of PCP contamination. Microcosms (3 0 g dry weight of soil) were incubated with labelled PCP (6.76% C-13 non-ra dioactive stable isotope, 22 mg kg(-1) dry weight) for 60 days. M. chloroph enolicum PCP-1 (7.8 x 10(6) cells g(-1) dry weight) was added to some sampl es. 50% of the PCP was mineralized in non-sterile soil with or without the exogenous bacteria. Only 5% of the PCP was mineralized in sterile soil with or without bacteria. These data suggest that the PCP was not accessible to M. chlorophenolicum and that the indigenous soil microflora can mineralize PCP.