<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Anaerobic reductive dechlorination of 2,3-dichlorophenol (2,3DCP) and 2,4,6-trichlorophenol (2,4,6TCP) was investigated in microcosms from River Nile sediment. A stable sediment-free anaerobic microbial consortium reductively dechlorinating 2,3DCP and 2,4,6TCP was established. Defined sediment-free cultures showing stable dechlorination were restricted to <italic>ortho</italic> chlorine when enriched with hydrogen as the electron donor, acetate as the carbon source, and either 2,3-DCP or 2,4,6-TCP as electron acceptors. When acetate, formate, or pyruvate were used as electron donors, dechlorination activity was lost. Only lactate can replace dihydrogen as an electron donor. However, the dechlorination potential was decreased after successive transfers. To reveal chlororespiring species, the microbial community structure of chlorophenol-reductive dechlorinating enrichment cultures was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments. Eight dominant bacteria were detected in the dechlorinating microcosms including members of the genera <italic>Citrobac- ter</italic>, <italic>Geobacter</italic>, <italic>Pseudomonas</italic>, <italic>Desulfitobacterium</italic>, <italic>Desulfovibrio</italic> and <italic>Clostridium.</italic> Highly enriched dechlorinating cultures were dominated by four bacterial species belonging to the genera <italic>Pseudomonas</italic>, <italic>Desulfitobacterium</italic>, and <italic>Clostridium</italic>. <italic>Desulfitobacterium</italic> represented the major fraction in DGGE profiles indicating its importance in dechlorination activity, which was further confirmed by its absence resulting in complete loss of dechlorination. Reductive dechlorination was confirmed by the stoichiometric dechlorination of 2,3DCP and 2,4,6TCP to metabolites with less chloride groups and by the detection of chlorophenol RD <italic>cpr</italic>A gene fragments in dechlorinating cultures. PCR amplified <italic>cpr</italic>A gene fragments were cloned and sequenced and found to cluster with the <italic>cpr</italic>A/<italic>pce</italic>A type genes of <italic>Dehalobacter restrictus</italic>.
</p>
</abstract>

Anaerobic reductive dechlorination of 2,3-dichlorophenol (2,3DCP) and 2,4,6-trichlorophenol (2,4,6TCP) was investigated in microcosms from River Nile sediment. A stable sediment-free anaerobic microbial consortium reductively dechlorinating 2,3DCP and 2,4,6TCP was established. Defined sediment-free cultures showing stable dechlorination were restricted to ortho chlorine when enriched with hydrogen as the electron donor, acetate as the carbon source, and either 2,3-DCP or 2,4,6-TCP as electron acceptors. When acetate, formate, or pyruvate were used as electron donors, dechlorination activity was lost. Only lactate can replace dihydrogen as an electron donor. However, the dechlorination potential was decreased after successive transfers. To reveal chlororespiring species, the microbial community structure of chlorophenol-reductive dechlorinating enrichment cultures was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments. Eight dominant bacteria were detected in the dechlorinating microcosms including members of the genera Citrobac- ter, Geobacter, Pseudomonas, Desulfitobacterium, Desulfovibrio and Clostridium. Highly enriched dechlorinating cultures were dominated by four bacterial species belonging to the genera Pseudomonas, Desulfitobacterium, and Clostridium. Desulfitobacterium represented the major fraction in DGGE profiles indicating its importance in dechlorination activity, which was further confirmed by its absence resulting in complete loss of dechlorination. Reductive dechlorination was confirmed by the stoichiometric dechlorination of 2,3DCP and 2,4,6TCP to metabolites with less chloride groups and by the detection of chlorophenol RD cprA gene fragments in dechlorinating cultures. PCR amplified cprA gene fragments were cloned and sequenced and found to cluster with the cprA/pceA type genes of Dehalobacter restrictus.

Characterization of a Highly Enriched Microbial Consortium Reductively Dechlorinating 2,3-Dichlorophenol and 2,4,6-Trichlorophenol and the Corresponding <italic>cpr</italic>A Genes from River Sediment

Polish Journal of Microbiology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Characterization of a Highly Enriched Microbial Consortium Reductively Dechlorinating 2,3-Dichlorophenol and 2,4,6-Trichlorophenol and the Corresponding A Genes from River Sediment

Anaerobic reductive dechlorination of 2,3-dichlorophenol (2,3DCP) and 2,4,6-trichlorophenol (2,4,6TCP) was investigated in microcosms from River Nile sediment....

Characterization of a Highly Enriched Microbial Consortium Reductively Dechlorinating 2,3-Dichlorophenol and 2,4,6-Trichlorophenol and the Corresponding cprA Genes from River Sediment

Published Online: Aug 26, 2016

Page range: 341 - 352

Received: Aug 04, 2015

Accepted: Mar 22, 2016

DOI: https://doi.org/10.5604/17331331.1215613

Keywords
16S rDNA, chlorophenol, A gene, DGGE, reductive dechlorination

© 2016 WAEL S. EL-SAYED published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Characterization of a Highly Enriched Microbial Consortium Reductively Dechlorinating 2,3-Dichlorophenol and 2,4,6-Trichlorophenol and the Corresponding cprA Genes from River Sediment

Published Online: Aug 26, 2016

Page range: 341 - 352

Received: Aug 04, 2015

Accepted: Mar 22, 2016

DOI: https://doi.org/10.5604/17331331.1215613

Keywords16S rDNA, chlorophenol, A gene, DGGE, reductive dechlorination

© 2016 WAEL S. EL-SAYED published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
16S rDNA, chlorophenol, A gene, DGGE, reductive dechlorination