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
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...
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| Format: | Article |
| Language: | English |
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Sciendo
2016-08-01
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| Series: | Polish Journal of Microbiology |
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| Online Access: | https://www.exeley.com/exeley/journals/polish_journal_of_microbiology/65/3/pdf/10.5604_17331331.1215613.pdf |
| _version_ | 1811220658183471104 |
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| author | Wael S. El-Sayed |
| author_facet | Wael S. El-Sayed |
| author_sort | Wael S. El-Sayed |
| collection | DOAJ |
| description | 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 Citrobac­ter, 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. |
| first_indexed | 2024-04-12T07:45:38Z |
| format | Article |
| id | doaj.art-367f8b3207224e098af1dba2b5e3d648 |
| institution | Directory Open Access Journal |
| issn | 1733-1331 2544-4646 |
| language | English |
| last_indexed | 2024-04-12T07:45:38Z |
| publishDate | 2016-08-01 |
| publisher | Sciendo |
| record_format | Article |
| series | Polish Journal of Microbiology |
| spelling | doaj.art-367f8b3207224e098af1dba2b5e3d6482022-12-22T03:41:43ZengSciendoPolish Journal of Microbiology1733-13312544-46462016-08-0165310.5604/17331331.1215613Characterization of a Highly Enriched Microbial Consortium Reductively Dechlorinating 2,3-Dichlorophenol and 2,4,6-Trichlorophenol and the Corresponding cprA Genes from River SedimentWael S. El-Sayed0Microbiology Department, Faculty of Science, Ain Shams University, Cairo, EgyptAnaerobic 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 Citrobac­ter, 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.https://www.exeley.com/exeley/journals/polish_journal_of_microbiology/65/3/pdf/10.5604_17331331.1215613.pdf16S rDNAchlorophenolcprA geneDGGEreductive dechlorination |
| spellingShingle | Wael S. El-Sayed 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 Polish Journal of Microbiology 16S rDNA chlorophenol cprA gene DGGE reductive dechlorination |
| title | 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 |
| title_full | 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 |
| title_fullStr | 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 |
| title_full_unstemmed | 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 |
| title_short | 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 |
| title_sort | 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 |
| topic | 16S rDNA chlorophenol cprA gene DGGE reductive dechlorination |
| url | https://www.exeley.com/exeley/journals/polish_journal_of_microbiology/65/3/pdf/10.5604_17331331.1215613.pdf |
| work_keys_str_mv | AT waelselsayed characterizationofahighlyenrichedmicrobialconsortiumreductivelydechlorinating23dichlorophenoland246trichlorophenolandthecorrespondingcpragenesfromriversediment |