Biodegradation of 2,4,5-trichlorophenoxyacetic acid in liquid culture and in soil by the white rot fungus Phanerochaete chrysosporium (original) (raw)

Extensive biodegradation of [14C]-2,4,5-trichlorophenoxyacetic acid ([14C]-2,4,5-T) by the white rot fungus Phanerochaete chrysosporium was demonstrated in nutrient nitrogen-limited aqueous cultures and in [14C]-2,4,5-T-contaminated soil inoculated with this fungus and supplemented with ground corn cobs. After incubation of [14C]-2,4,5-T with aqueous cultures of the fungus for 30 days, 62.0% + 2.0% of the [14C]-2,4,5-T initially present was degraded to 14CO2. Mass balance analysis demonstrated that water soluble metabolites were formed during degradation, and HPLC and thin layer chromatography (TLC) of methylene chloride-extractable material revealed the presence of polar and non-polar [14C]-2,4,5-T metabolites. It was also shown that only ~ 5% of the [14C]-2,4,5-T initially present in cultures remained as undegraded [14C]-2,4,5-T. In incubations composed of [~4C]-2,4,5-T-contaminated soil, ground corn cobs, and 40% (w/w) water, 32.5%+ 3.6% of the [~4C]-2,4,5-T initially present was converted to ~4CO2 after 30 days of incubation. These results suggest that it may be possible to develop practical systems based on the use of this fungus to detoxify 2,4,5-T-contaminated water and soil.