Microbial enrichment culture-mediated reductive dechlorination of perchloroethylene (PCE) with the potential involvement of Shewanella

Abstract:

[Background] Chlorinated aliphatic hydrocarbons have become persistent organic pollutants in soil and groundwater due to their extensive use in industrial and agricultural production and improper discharge, posing serious threats to the environment and human health. [Objective] To screen microbial consortia from a chemical production site that are capable of reductively dechlorinating perchloroethylene (PCE). [Methods] Enrichment culture techniques were employed to isolate PCE-degrading consortia from soil samples. The consortium composition and key strains were characterized via amplicon sequencing, 16S rRNA gene sequencing, and Sanger sequencing. GC-MS was used to monitor PCE and its dechlorination products. [Results] The enrichment culture from sample t1 successfully achieved the dechlorination of PCE. Microbial diversity analysis revealed that organohalide-respiring bacteria were dominated by Shewanella, and a strain preliminarily identified as Shewanella sp. BS1 was found within this enrichment culture. [Conclusion] This study demonstrates that the obtained enrichment culture mediates the reductive dechlorination of PCE. Although preliminary results suggest that Shewanella spp. may play a potential role in this process, further pure culture isolation and in-depth studies are still needed to definitively elucidate the specific dechlorination function and exact contribution of Shewanella sp. BS1 to the PCE transformation pathway. These findings provide a scientific basis for elucidating bioremediation mechanisms at chlorinated hydrocarbon-contaminated sites and informing subsequent engineering applications.