Regulating the dechlorination and methanogenesis synchronously to achieve a win-win remediation solution for γ-hexachlorocyclohexane polluted anaerobic environment

Conductive Materials on Biocathodes Altered the Electron-Transfer Paths and Modulated γ-HCH Dechlorination and CH4 Production in Microbial Electrochemical Systems

“…A mixed microbial consortium capable of dechlorinating γ-HCH was used as the inoculum. 6 It was originally obtained from a rice paddy polluted with polychlorinated biphenyl (Taizhou City, Zhejiang Province, China). Basic characterization of the consortium is in Part 1 of the Supporting Information (SI).…”

“…At the end of the experiments, we collected biocathode samples from four replicates for DNA extraction. The detailed methods for DNA extraction, amplification, 16S rDNA Illumina MiSeq sequencing, and taxonomic classification were previously described and are summarized in Part 3 of the SI. All sequences were submitted to the NCBI Sequence Read Archive (SRA) database with the accession number of SRP326475 for Bacteria and SRP326513 for Archaea.…”

“…The composition and structure of bacterial and archaeal communities were revealed in terms of alpha and beta diversity, phyla and genera composition, microbial networks, and Spearman correlations. ,, These methods are described in Part 6 of the SI. We analyzed the statistical significance of the difference in the data by measuring one-way analysis of variance (ANOVA).…”

“…4 Electron transfer to reductively dechlorinate γ-HCH has been proven to co-occur alongside the reduction of CO 2 in a methanogenic process, 5 in which electron sinks that could compete with dechlorination were hydrogenotrophic methanogenesis (CO 2 + 4H 2 → CH 4 + 2H 2 O) and acetogenesis (2CO 2 + 4H 2 → CH 3 COO − + H + + 2H 2 O), with the acetate being fermented to CH 4 . 6 Although γ-HCH reduction and methanogenesis compete for the electron donor, 7 dechlorination was accelerated in the presence of methanogenesis, 8,9 perhaps because the methanogens produced vital cofactors for dechlorinators, like vitamin B 12 . 5,10 A microbial electrochemical system (MES) was capable of dechlorinating chlorinated organic pollutants (COPs) and producing CH 4 at its biocathode.…”

Molecular Insights into the Response of Nonelectroactive Bacteria to Electro-stimulation: Growth and Metabolism Regulation Mechanism

“…These non-EAB were either not equipped with extracellular electronic shuttle channels ( i.e. , some fermentative bacteria) or could not perform EET due to being far away from electrodes (planktonic microbes). − Interestingly, certain non-EAB could also make positive contributions to the synergetic removal of contaminants via either supplying simple substrates to EAB or performing independently. , Understanding whether and how these microbes respond to electro-stimulation is crucial for revealing the role of significant quantities of non-EAB in the electro-biostimulation systems.…”