Biodegradation of Heptachlor by Phanerochaete chrysosporium ME 446: The Toxic Effects of Heptachlor and Its Metabolites on Mice

On the basis of degradation properties of Phanerochaete chroysosporium ME 446 found in white-rot fungi in respect of many organic compounds with toxic, mutagenic and carcinogenic characteristics, the physiological conditions effective for the degradation of heptachlor (1, 4, 5, 6, 7, 8, 8heptachloro-3a, 4, 7, 7a-tetrahydro-4, 7-methanoindene), an organic chlorine used in insecticides Phanerochaete chrysosporium ME were determined. The potential toxic effects of heptachlor and metabolites on mice were also investigated. For the degradation of heptachlor, the optimum pH was found to be 5, incubation period 20 days, and incubation temperature, 30C-35C, while the optimum concentrations was 50 μM. The maximum heptachlor degradation rate under optimum physiological conditions was found to be 97.30%. The LD 50 dose of heptachlor was determined, and its effects on cells in the blood of mice were investigated. The LD 50 dose was found to be 97.50 mg/kg for heptachlor. Although this dose normally produces a death rate of 50% in mice, the resultant metabolites obtained through Phanerocheate chrysosporium ME 446 treatment caused no deaths. While direct application of heptachlor produced quantitive effects in the blood cells, no significant effects of heptachlor metabolites could be detected.