Author(s): Thomas DR, Carswell KS, Georgiou G
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Abstract The white rot fungus Phanerochaete chrysosporium is unique in its ability to totally degrade a wide variety of recalcitrant pollutants. We have investigated the degradation of biphenyl and two model chlorinated biphenyls, 2,2',4,4'-tetrachlorobiphenyl and 2-chlorobiphenyl by suspended cultures of P. chrysosporium grown under conditions that maximize the synthesis of lignin-oxidizing enzymes. Radiolabeled biphenyl and 2'-chlorobiphenyl added to cultures at concentrations in the range 260 nM to 8.8 microM were degraded extensively to CO(2) within 30 days. In addition, from 40\% to 60\% of the recovered radioactivity was found in water-soluble compounds. A correlation between the rate of degradation and the synthesis of ligninases or Mn-dependent peroxidases could not be observed, indicating that yet unknown enzymatic system may be responsible for the initial oxidation of PCBs. The more heavily chlorinated PCB congener, 2,2',4,4'-tetrachlorobiphenyl was converted to CO(2) less readily; approximately 9\% and 0.9\% mineralization was observed in cultures incubated with 40 nM and 5.3 microM, respectively. Overall, our results indicate that P. chrysosporium is a promising organism for the treatment of wastes contaminated with lightly and moderately chlorinated PCBs. (c) 1992 John Wiley & Sons, Inc.
This article was published in Biotechnol Bioeng
and referenced in Journal of Petroleum & Environmental Biotechnology