Polymerase Chain Reaction (PCR) Analysis of Microbial Consortia in Wastewater Treatment Processes for High Explosives

The engineering aspects of bioreactors treating wastewaters contaminated with high explosives are better understood than the microbial communities within the reactors. Five anaerobic bioreactors treating energetics were studied to better understand bacterial compositions in each reactor system as related to influents containing various energetic materials. Studied were: three anaerobic fluidized bed reactors (AFBR) treating DNAN and MNA; one gas lift bioreactor (GLBR) treating ammonium perchlorate; and one pilot-scale granulated activated carbon-fluidized bed reactor (GAC-FBR) treating TNT, RDX, and TNB. Bacterial profiles were derived by cloning and sequencing the total 16S rRNA genes from each reactor contaminant combination. In the presence of DNAN and MNA, the AFBRs communities showed bacteria of the phylum Chloroflexi represented 30 percent of the total clone distribution in each reactor. In the presence of ammonium perchlorate, the GLBR was composed primarily of Proteobacteria in excess of 60 percent of the clone distribution. The GAC-FBR treating TNT, RDX, and TNB was enriched in both Chloroflexi and Proteobacteria (37 and 27 percent of the total clone distribution, respectively). Assuming the most prevalent bacteria were enriched by the presence of the contaminant, the data indicated that Chloroflexi and Proteobacteria likely played an important roll in energetic degradation. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR. ERDC/CERL TR-09-34 iii