DEGRADATION OF PENTACHLOROPHENOL BY THE WHITE-ROT FUNGUS PHANEROCHAETE-CHRYSOSPORIUM GROWN IN AMMONIUM LIGNOSULFONATE MEDIA

Removal and degradation of pentachlorophenol (PCP) by Phanerochaete ch rysosporium in static flask cultures was studied using ammonium lignos ulphonates (LS), a waste product of the papermill industry, as a carbo n and nitrogen source. After 3 days, cultures of P. chrysosporium grow n in either a 2% LS (nitrogen-sufficient) medium or a 0.23% LS and 2% glucose (nitrogen-deficient) medium removed 72 to 75% of PCP, slightly less than the 95% removal seen using nitrogen-deficient glucose and a mmonia medium. PCP dehalogenation occurred despite the fact that extra cellular enzyme (LiP) activity, measured by a veratryl alcohol oxidati on assay and by PCP disappearance in cell-free extracts, was inhibited by LS. This inactivation of LiP likely contributed to the lower perce nt of PCP dehalogenation observed using the LS media. In order to bett er understand the relationship between PCP disappearance and dehalogen ation, we measured the fate of the chlorine in PCP. After 13 days, onl y 1.8% of the initial PCP added was recoverable as PCP. The remainder of the PCP was either mineralized or transformed to breakdown intermed iates collectively identified as organic halides. The largest fraction of the original chlorine (58%) was recovered as organic (non-PCP) hal ide, most of which (73%) was associated with the cell mass. Of the rem aining chlorine, 40% was released as chloride ion, indicating a level of dehalogenation in agreement with previously reported values.