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https://hdl.handle.net/11681/5324| Title: | Effect of acetonitrile on RDX biodegradation in an unsaturated surface soil |
| Authors: | Ringelberg, David B. Reynolds, Charles M. (Charles Michael), 1950- Perry, Lawrence B. Foley, Karen L. |
| Keywords: | Acetonitrile Microbial ecology Phospholipids |
| Publisher: | Cold Regions Research and Engineering Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
| Series/Report no.: | ERDC/CRREL ; TR-05-5 |
| Abstract: | In previous work, we documented the biodegradation of hexahydro-1,3,5- trinitro-1,3,5-triazine (RDX) in an unsaturated cold-region surface soil and showed that acetonitrile (ACN) could inhibit RDX removal rates when used as a dispersant for the contaminant. Here, we document that the added ACN had an effect on microbial community development in the RDX-contaminated soil. In the absence of ACN, the soils showed a striking increase in microbial biomass and in biomarkers indicative of microfauna. A four-fold increase in the phospholipid fatty acid (PLFA) biomarkers 18:2w6 and 20:4w6 (approximately 4–16 mol %) coincided with a greater than two-fold increase in total microbial biomass (approximately 15–35 nmol g⁻¹ PLFA). In the presence of ACN (1% aqueous concentration), these increases were not observed. The ACN-free soils also showed a significant decrease in PLFA biomarkers for Gram-negative bacteria (i.e., approximately 15 mol% decrease in w7 monounsaturated PLFA). This decrease was not observed in soils amended with 1% ACN. We concluded that the organic solvent interfered with microbial community development, specifically the trophic interaction between free-living protozoa and Gram-negative bacteria. Since the addition of 1% ACN increased the half-life for RDX from 29 to 48 days, the trophic interaction may be a necessary component in the development of an RDX-biodegrading microbial community. |
| Description: | Technical Report |
| URI: | http://hdl.handle.net/11681/5324 |
| Appears in Collections: | Technical Report |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| CRREL-TR-05-5.pdf | 318.4 kB | Adobe PDF |  View/Open |