Biodegradation of methoxychlor and its metabolites by the white rot fungus Stereum hirsutum related to the inactivation of estrogenic activity.
The white rot fungus Stereum hirsutum was used to degrade methoxychlor [2,2,2-trichloro-1,1-bis(4-methoxyphenyl)ethane] in culture and the degraded products were extensively determined. The estrogenic activity of the degraded products of methoxychlor was examined using cell proliferation and pS2 gene expression assays in MCF-7 cells. S. hirsutum showed high resistance to methoxychlor 100 ppm, and the mycelial growth was fully completed within 8 days of incubation at 30 degrees C. Methoxychlor in liquid culture medium was gradually converted into 2,2-dichloro-1,1-bis(4-methoxyphenyl)ethane, 2,2-dichloro-1,1-bis(4-methoxyphenyl)ethylene, 2-chloro-1,1-bis(4-methoxyphenyl) ethane, 2-chloro-1,1-bis(4-methoxyphenyl) ethylene, and 1,1-bis(4-methoxyphenyl)ethylene, indicating that methoxychlor is dominantly degraded by dechlorination and dehydrogenation. MCF-7 cells were demonstrated to proliferate actively at the 10-5 M concentration of methoxychlor. However, cell proliferation was significantly inhibited by the incubation with methoxychlor culture media containing S. hirsutum. In addition, the expression level of pS2 mRNA was increased at the concentration (10-5 M) of methoxychlor. The reductive effect of S. hirsutum for methoxychlor was clear but not significant as in the proliferation assay.
Lee
Soo-Min
SM
Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea.
Lee
Jae-Won
JW
Park
Ki-Ryeong
KR
Hong
Eui-Ju
EJ
Jeung
Eui-Bae
EB
Kim
Myung-Kil
MK
Kang
Ha-Young
HY
Choi
In-Gyu
IG
D001487:Basidiomycota / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002455:Cell Division; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004968:Estrogens, Non-Steroidal / Q000032:analysis / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D008731:Methoxychlor / Q000378:metabolism*
D004968:Estrogens, Non-Steroidal; D007306:Insecticides; D008731:Methoxychlor