| CENSUS - Anaerobic BTEX |
Detect and quantify bacteria responsible for anaerobic biodegradation of petroleum hydrocarbonsBTEX compounds are susceptible to biodegradation under anoxic and anaerobic conditions although biodegradation pathways for each compound are not as well characterized as aerobic pathways. Of the BTEX compounds, toluene biodegradation under anaerobic conditions has been the most studied. The first step in this pathway, mediated by benzylsuccinate synthase (bssA), is the addition of fumarate onto the toluene methyl group to form benzylsuccinate. In general, anaerobic biodegradation of o-xylene and m-xylene proceeds via an analogous pathway. Moreover, bacterial isolates capable of anaerobic toluene biodegradation are often also capable of anaerobic xylene metabolism. Two pathways have been proposed for the anaerobic biodegradation of ethylbenzene. One is similar to that of anaerobic toluene and xylene biodegradation where the first step is the addition of fumarate. The pathway for anaerobic biodegradation of benzene has not been elucidated as yet and identification of intermediates suggests a different approach may be used. CENSUS Target for Anaerobic BTEX
ReferencesBeller, H.R., S.R. Kane, T.C. Legler, and P.J.J. Alvarez. 2002. “A real-time polymerase chain reaction method for monitoring anaerobic, hydrocarbon-degrading bacteria based on a catabolic gene.” Environmental Science & Technology 36(18): 3977-3984. Sublette, K., A. Peacock, D. White, G. Davis, D. Ogles, D. Cook, R. Kolhatkar, D. Beckmann, and X. Yang. 2006. “Monitoring subsurface microbial ecology in a sulfate-amended, gasoline-contaminated aquifer.” Ground Water Monitoring & Remediation 26(2): 70-78. |
Benzylsuccinate Synthase (qBSS): Benzylsuccinate synthase is responsible for the activation of anaerobic toluene biodegradation by mediating the addition of fumarate onto the methyl group of toluene. As described above, anaerobic biodegradation of xylene isomers involves an analogous step. In column studies, rapid toluene biodegradation was associated with the largest populations of bssA harboring bacteria. In field studies, substantial increases in bssA populations were also noted following sulfate injection to stimulate anaerobic BTEX biodegradation.
