Biodegradation of cis-1,2-dichloroethylene and vinyl chloride in anaerobic cultures enriched from landfill leachate sediment under Fe(III)-reducing conditions.

An anaerobic, Fe(III)-reducing enrichment culture, which originated from a sediment sample collected at a landfill in Nanji-do, Seoul, Korea, was capable of degrading cis-1,2-dichloroethylene (cis-DCE) and vinyl chloride (VC). Although it exhibited the ability under Fe(III)-reducing conditions, the chlorinated ethenes degradation was not linked to the Fe(III) reduction. During cis-DCE degradation, no VC, ethene, or ethane was detected through the experimental period. Also, this culture did not accumulate ethene and ethane during the VC degradation. It was unlikely that cis-DCE was reductively dechlorinated to VC and then the VC formed was dechlorinated fast enough. Because the kinetic data showed that the rate of cis-DCE degradation was 3.5 times higher than that of VC. Whereas glucose supported the culture growth and the degradation, formate, acetate, butyrate, propionate, lactate, pyruvate, and yeast extract did not. The results appeared consistent with the involvement of oxidative degradation mechanism rather than reductive dechlorination mechanism. The traits of the culture described here are unusual in the anaerobic degradation of chlorinated ethenes and may be useful for searching an effective organism and mechanism regarding anaerobic cis-DCE and VC degradation.