Substrates and Substrate Interactions in Anaerobic Dechlorinating Cultures

Bioremediation of chlorinated contaminants in groundwater can be achieved by reductive dechlorination by anaerobic dechlorinating cultures. However, at sites impacted with multiple different chlorinated contaminants, reductive dechlorination is often inhibited by co-contaminants. The inhibitory effects of trichloroethene, cis-dichloroethene and vinyl chloride on chloroform dechlorination were studied using a Dehalobacter-containing chloroform dechlorinating mixed culture (ACT-3). The inhibitory effect of chloroform on chlorinated ethene dechlorination was studied in a Dehalococcoides-containing trichloroethene dechlorinating mixed culture (KB-1). Vinyl chloride was found to be the strongest inhibitor of chloroform in ACT-3. Chloroform exerted a complex and strong inhibitory effect on chlorinated ethene dechlorination in KB-1. The potential for microbial reductive defluorination was also examined in the enrichment cultures. Quantifying the substrates and substrate interactions in dechlorinating cultures is necessary to most efficiently use these cultures to remediate contaminated sites.MAS