title: Congener specific polychlorinated biphenyl metabolism by human intestinal microbeClostridiumspecies: Comparison with human liver cell line-HepG2.
abstract: Polychlorobiphenyls (PCBs), which adversely affect human fetal and infant development, are endocrine disrupter and cause neurological disorders. They may also be carcinogenic. It is not known whether these effects are due to whole PCBs or to its metabolites, produced by the human gastrointestinal system primarily the liver and/or by intestinal microbes such as Clostridium sp. The available data show thatClostridium perfringens, the most prominent species of Clostridium occurs in the human gut.C. beijerinckii is a special type of Clostridium present in the gut of autistic children with late onset autism. Since mixed cultures are better PCB metabolizers than single cultures, mixed cultures of Clostridium were used in this work. The first step in PCB degradation is the removal of the chlorine atoms and then the breaking open of the phenyl ring leading to the final degradation product: CO2. In this study, GC-MS analyses were done to examine the effect of Clostridium sp. on PCB-153 and PCB-77 and the metabolites obtained with Clostridium sp. therein. In this paper, we report that the unlike human liver cells which cannot produce any PCB metabolites. Mixed Clostridium spp. can degrade these PCBs. Clostridium spp. and were able to dechlorinate PCB 153 (hexachlorobiphenyl) to pentachlorobiphenyl and PCB 77 (tetrachlorobiphenyl) to trichlorobiphenyl. Despite considerable absorption of PCB 153 (40%) and PCB 77 (50%) in 30 minutes and 1.5 hours respectively by human liver (HepG2) cells, they can not dechlorinate PCBs. It has been observed that slight differences in chemical structures of PCBs such as coplanar (PCB-77) vs. non-coplanar (PCB-153) has significant metabolic effects.
authors.affiliation: Department of Biology, Howard University, DC EE Just Hall, Room # 335, 415 College Street, NW, Washington DC 20001, USA.
authors.forename: Supriyo
authors.initials: S
authors.lastname: De
authors.affiliation: Department of Biology, Howard University, DC EE Just Hall, Room # 335, 415 College Street, NW, Washington DC 20001, USA.
authors.forename: Somiranjan
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Department of Biology, Howard University, DC EE Just Hall, Room # 335, 415 College Street, NW, Washington DC 20001, USA.
authors.forename: Sisir K
authors.initials: SK
authors.lastname: Dutta
keywords: Clostridium spp.; HepG2; PCB-153; PCB-77; metabolites
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