Enrichment of Microorganisms That Sequentially meta, para-Dechlorin- ate the Residue of Aroclor 1260 in Housatonic River Sediment

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• 作者：Donna L. Bedard ; Heidi M. Van Dort ; Ralph J. May ; and Lynn A. Smullen
• 刊名：Environmental Science & Technology
• 出版年：1997
• 出版时间：November 1997
• 年：1997
• 卷：31
• 期：11
• 页码：3308 - 3313
• 全文大小：221K
• 年卷期：v.31,no.11(November 1997)
• ISSN：1520-5851

文摘

2,3,4,5,6-Pentachlorobiphenyl (23456-CB) primes a broadspecificity meta-dechlorination (Process N) of Aroclor1260in Housatonic River sediments. We hypothesizedthat23456-CB acts as an electron acceptor and could be usedto selectively enrich PCB-dechlorinating microorganisms.Here we sought to (a) enrich the microbial populationresponsible for Process N dechlorination and (b) determinewhether bioaugmentation with the enriched culture wouldstimulate effective PCB dechlorination. We made fourserial transfers of actively dechlorinating slurries(10-20%of the final volume) plus 23456-CB to autoclaved PCB-contaminated sediment. The enrichment proceduregreatlyenhanced Process N dechlorination, reducing the hexa-through nonachlorobiphenyls in the sediment from 66.3 mol% initially to only 16.7 mol % in the fourth generation.Theenrichment also fostered a newpara-dechlorinationactivity (Process LP) that caused further conversion ofProcess N products to tri- and tetrachlorobiphenyls.Bioaugmentation without the primer resulted in only modestdechlorination. Our data demonstrate that enrichmentwith23456-CB results in an inoculum that, when primed, rapidlyand extensively dechlorinates weathered PCBs, evenwhen excess oil is present. The identification ofeffectiveenvironmentally acceptable non-PCB agents to prime andenrich PCB dechlorinators could lead to a technology forinsitu treatment of PCB-contaminatedsediments.