Microbes and monitoring tools for anaerobic chlorinated methane bioremediation

Justicia-Leon, Shandra D.

Title:

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