Microbes and monitoring tools for anaerobic chlorinated methane bioremediation

dc.contributor.advisor Löffler, Frank E.
dc.contributor.author Justicia-Leon, Shandra D.
dc.contributor.committeeMember Mack, E. Erin
dc.contributor.committeeMember Kubanek, Julia
dc.contributor.committeeMember Konstantinidis, Konstantinos T.
dc.contributor.committeeMember Taillefert, Martial
dc.contributor.committeeMember DiChristina, Thomas J.
dc.contributor.department Biology
dc.date.accessioned 2015-01-26T19:44:31Z
dc.date.available 2015-01-26T19:44:31Z
dc.date.issued 2012-12
dc.description.abstract he chlorinated methanes carbon tetrachloride (CT), chloroform (CF), dichloromethane (DCM) and chloromethane (CM) are widespread groundwater pollutants that pose risks to human and ecosystem health. Although some progress has been made in elucidating the microbiology contributing to the aerobic degradation of DCM and CM, these efforts have had little impact on bioremediation practices aimed at restoring anoxic aquifers impacted by chlorinated methanes. Remaining knowledge gaps include the lack of understanding of the microbial mechanisms and pathways contributing to chlorinated methane transformations under anoxic conditions. Thus, the major goals of this research effort were to identify microbes that can contribute to the transformation of chlorinated methanes in the absence of oxygen, and to develop monitoring tools to assess anaerobic chlorinated methane bioremediation at contaminated sites. To accomplish these goals, freshwater and estuarine sediment samples from 45 geographically distinct locations, including 3 sites with reported chlorinated-methane contamination, were collected and screened for CT-, CF-, DCM- and/or CM-degrading activity. DCM degradation was observed in microcosms established with sediment materials from 15 locations, and the sediment-free, DCM-degrading enrichment culture RM was obtained from Rio Mameyes sediment. 16S rRNA-gene based community analysis characterized consortium RM, and identified a Dehalobacter sp. involved in DCM fermentation to non-toxic products. Organism- and process-specific monitoring tools were designed that target the 16S rRNA gene of the DCM-fermenting Dehalobacter sp. and the consortium’s specific 13C-DCM enrichment factor, respectively. Treatability studies using site materials that showed no chlorinated methane degradation activity demonstrated the feasibility of using CF- and DCM-degrading consortia for bioaugmentation applications. Collectively, this study expands our understanding of bacteria contributing to chlorinated methane degradation, provides new tools for monitoring anaerobic DCM degradation, and demonstrates that microbial remedies at chlorinated methane contaminated sites are feasible. en_US
dc.description.degree Ph.D.
dc.embargo.terms null en_US
dc.identifier.uri http://hdl.handle.net/1853/53151
dc.language.iso en_US en_US
dc.publisher Georgia Institute of Technology en_US
dc.subject Dichloromethane en_US
dc.subject Chloroform en_US
dc.subject Bioremediation en_US
dc.subject Carbon tetrachloride en_US
dc.title Microbes and monitoring tools for anaerobic chlorinated methane bioremediation en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.corporatename College of Sciences
local.contributor.corporatename School of Biological Sciences
relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication c8b3bd08-9989-40d3-afe3-e0ad8d5c72b5
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