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Title: The corrinoid cofactor of reductive dehalogenases affects dechlorination rates and extents in organohalide-respiring Dehalococcoides mccartyi

Abstract

Corrinoid auxotrophic organohalide-respiring Dehalococcoides mccartyi (Dhc) strains are keystone bacteria for reductive dechlorination of toxic and carcinogenic chloroorganic contaminants. We demonstrate that the lower base attached to the essential corrinoid cofactor of reductive dehalogenase (RDase) enzyme systems modulates dechlorination activity and affects the vinyl chloride (VC) RDases BvcA and VcrA differently. Amendment of 5,6-dimethylbenzimidazolyl-cobamide (DMB-Cba) to Dhc strain BAV1 and strain GT cultures supported cis-1,2-dichloroethene-to-ethene reductive dechlorination at rates of 107.0 (±12.0) μM and 67.4 (±1.4) μM Cl - released per day, respectively. Strain BAV1, expressing the BvcA RDase, reductively dechlorinated VC to ethene, although at up to fivefold lower rates in cultures amended with cobamides carrying 5-methylbenzimidazole (5-MeBza), 5-methoxybenzimidazole (5-OMeBza) or benzimidazole (Bza) as the lower base. In contrast, strain GT harboring the VcrA RDase failed to grow and dechlorinate VC to ethene in medium amended with 5-OMeBza-Cba or Bza-Cba. The amendment with DMB to inactive strain GT cultures restored the VC-to-ethene-dechlorinating phenotype and intracellular DMB-Cba was produced, demonstrating cobamide uptake and remodeling. The distinct responses of Dhc strains with BvcA versus VcrA RDases to different cobamides implicate that the lower base exerts control over Dhc reductive dechlorination rates and extents (that is, detoxification), and therefore the dynamics ofmore » Dhc strains with discrete reductive dechlorination capabilities. Furthermore, these findings emphasize that the role of the corrinoid/lower base synthesizing community must be understood to predict strain-specific Dhc activity and achieve efficacious contaminated site cleanup.« less

Authors:
 [1];  [2];  [2];  [2];  [2];  [2]; ORCiD logo [1]
  1. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Univ. of Tennessee, Knoxville, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1468287
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
The ISME Journal
Additional Journal Information:
Journal Volume: 10; Journal Issue: 5; Journal ID: ISSN 1751-7362
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Yan, Jun, Şimşir, Burcu, Farmer, Abigail T., Bi, Meng, Yang, Yi, Campagna, Shawn R., and Löffler, Frank E. The corrinoid cofactor of reductive dehalogenases affects dechlorination rates and extents in organohalide-respiring Dehalococcoides mccartyi. United States: N. p., 2015. Web. doi:10.1038/ismej.2015.197.
Yan, Jun, Şimşir, Burcu, Farmer, Abigail T., Bi, Meng, Yang, Yi, Campagna, Shawn R., & Löffler, Frank E. The corrinoid cofactor of reductive dehalogenases affects dechlorination rates and extents in organohalide-respiring Dehalococcoides mccartyi. United States. doi:10.1038/ismej.2015.197.
Yan, Jun, Şimşir, Burcu, Farmer, Abigail T., Bi, Meng, Yang, Yi, Campagna, Shawn R., and Löffler, Frank E. Tue . "The corrinoid cofactor of reductive dehalogenases affects dechlorination rates and extents in organohalide-respiring Dehalococcoides mccartyi". United States. doi:10.1038/ismej.2015.197. https://www.osti.gov/servlets/purl/1468287.
@article{osti_1468287,
title = {The corrinoid cofactor of reductive dehalogenases affects dechlorination rates and extents in organohalide-respiring Dehalococcoides mccartyi},
author = {Yan, Jun and Şimşir, Burcu and Farmer, Abigail T. and Bi, Meng and Yang, Yi and Campagna, Shawn R. and Löffler, Frank E.},
abstractNote = {Corrinoid auxotrophic organohalide-respiring Dehalococcoides mccartyi (Dhc) strains are keystone bacteria for reductive dechlorination of toxic and carcinogenic chloroorganic contaminants. We demonstrate that the lower base attached to the essential corrinoid cofactor of reductive dehalogenase (RDase) enzyme systems modulates dechlorination activity and affects the vinyl chloride (VC) RDases BvcA and VcrA differently. Amendment of 5,6-dimethylbenzimidazolyl-cobamide (DMB-Cba) to Dhc strain BAV1 and strain GT cultures supported cis-1,2-dichloroethene-to-ethene reductive dechlorination at rates of 107.0 (±12.0) μM and 67.4 (±1.4) μM Cl- released per day, respectively. Strain BAV1, expressing the BvcA RDase, reductively dechlorinated VC to ethene, although at up to fivefold lower rates in cultures amended with cobamides carrying 5-methylbenzimidazole (5-MeBza), 5-methoxybenzimidazole (5-OMeBza) or benzimidazole (Bza) as the lower base. In contrast, strain GT harboring the VcrA RDase failed to grow and dechlorinate VC to ethene in medium amended with 5-OMeBza-Cba or Bza-Cba. The amendment with DMB to inactive strain GT cultures restored the VC-to-ethene-dechlorinating phenotype and intracellular DMB-Cba was produced, demonstrating cobamide uptake and remodeling. The distinct responses of Dhc strains with BvcA versus VcrA RDases to different cobamides implicate that the lower base exerts control over Dhc reductive dechlorination rates and extents (that is, detoxification), and therefore the dynamics of Dhc strains with discrete reductive dechlorination capabilities. Furthermore, these findings emphasize that the role of the corrinoid/lower base synthesizing community must be understood to predict strain-specific Dhc activity and achieve efficacious contaminated site cleanup.},
doi = {10.1038/ismej.2015.197},
journal = {The ISME Journal},
number = 5,
volume = 10,
place = {United States},
year = {2015},
month = {11}
}

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