Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/es048037x
Title (Primary) In situ assessment of biodegradation potential using biotraps amended with 13C-labeled benzene or toluene
Author Geyer, R.; Peacock, A.D.; Miltner, A. ORCID logo ; Richnow, H.H.; White, D.C.; Sublette, K.L.; Kästner, M.
Source Titel Environmental Science & Technology
Year 2005
Department ISOBIO; UMB; UBT
Volume 39
Issue 13
Page From 4983
Page To 4989
Language englisch
Abstract Stable isotope fractionation analysis of an aquifer heavily contaminated with benzene (up to 850 mg L-1) and toluene (up to 50 mg L-1) at a former hydrogenation plant in Zeitz (Saxonia, Germany) has suggested that significant biodegradation of toluene was occurring. However, clear evidence of benzene biodegradation has been lacking at this site. Determining the fate of benzene is often a determining factor in regulatory approval of a risk-based management strategy. The objective of the work described here was the demonstration of a new tool that can be used to provide proof of biodegradation of benzene or other organics by indigenous microorganisms under actual aquifer conditions. Unique in situ biotraps containing Bio-Sep beads, amended with 13C-labeled or 12C nonlabeled benzene and toluene, were deployed at the Zeitz site for 32 days in an existing groundwater monitoring well and used to collect and enrich microbial biofilms. Lipid biomarkers or remaining substrate was extracted from the beads and analyzed by mass spectrometry and molecular methods. Isotopic analysis of the remaining amounts of 13C-labeled contaminants (about 15-18% of the initial loading) showed no alteration of the 12C/13C ratio during incubation. Therefore, no measurable exchange of labeled compounds in the beads by the nonlabeled compounds in the aquifer materials occurred. Isotopic ratio analysis of microbial lipid fatty acids (as methyl ester derivatives) from labeled benzene- and toluene-amended biotraps showed 13C enrichment in several fatty acids of up to d (13C) 13400‰, clearly verifying benzene and toluene biodegradation and the transformation of the labeled carbon into biomass by indigenous organisms under aquifer conditions. Fatty acid profiles of total lipid fatty acids and the phospholipid fatty acid fraction and their isotopic composition showed significant differences between benzene- and toluene-amended biotraps, suggesting that different microbial communities were involved in the biodegradation of the two compounds.
Persistent UFZ Identifier
Geyer, R., Peacock, A.D., Miltner, A., Richnow, H.H., White, D.C., Sublette, K.L., Kästner, M. (2005):
In situ assessment of biodegradation potential using biotraps amended with 13C-labeled benzene or toluene
Environ. Sci. Technol. 39 (13), 4983 - 4989 10.1021/es048037x