Characterization of Groundwater Microbial Communities from a Chlorinated-Ethene-Contaminated Landfill
Molecular (rDNA), phospholipid fatty acid analysis (PLFA), and substrate utilization (BIOLOG) techniques were used to assess structural and functional differences between groundwater microbial communities from a chlorinated-ethene (CE)-contaminated landfill. Prokaryotic cells were collected from pristine (LFW 43B) and CE-contaminated (LFW 62D) groundwater monitoring wells on 0.2 micron filters, DNA was extracted from the filters, and libraries were prepared. For well LFW 43B, 26 clones were examined by sequencing and restriction endonuclease patterns, and all were found to be closely related to Pseudomonas gessardii and P. libaniensis. For well LFW 62D, 40 bacterial clones were examined, and 17 ribotypes were found including representatives of type I and II methylotrophs, Pseudomonas spp., Zoogloea spp., and other proteobacteria. In an archaeal library from well LFW 62D, all 15 of the clones examined were nearly identical and possessed about 89 percent sequence similarity to Cenarchaeum symbiosum. PLFA analysis revealed that the communities from contaminated groundwater contained primarily gram-negative bacteria, as indicated by the predominance of the biomarker 16:1w7c. The bacteria were in the stationary growth phase as indicated by the abundance of cyclopropyl fatty acids cy17:0 and cy19:0 and their respective precursors 16:1w7c and 18:1w7c. Further, PLFA ratios for 16:1w7t/16:1w7c and 18:1w7t/18:1w7c were greater than 0.1, indicative of increased cellular membrane permeability. Using BIOLOG GN plates, a similar number of substrates were utilized in LFW43B (72) and LFW 62D (63) communities, even though inoculum densities were 2-orders of magnitude greater in LFW 62D. The combination of non-selective characterization techniques was useful to further our understanding of CE-contamination on groundwater microbial communities.
- Research Organization:
- Savannah River Site (SRS), Aiken, SC (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC09-96SR18500
- OSTI ID:
- 804928
- Report Number(s):
- WSRC-MS-2002-00172; TRN: US200223%%418
- Journal Information:
- Applied Environmental Microbiology, Other Information: PBD: 20 Nov 2002
- Country of Publication:
- United States
- Language:
- English
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