Indigenous Microbial Communities in Albertan Sediments are Capable of Anaerobic Benzene Biodegradation Under Methanogenic, Sulfate-reducing, Nitrate-reducing, and Iron-Reducing Redox Conditions.

Abstract

Alberta is a major center for oil and gas production, and correspondingly harbors hundreds of unresolved contamination sites by environmental hazards such as benzene (C H ). Due to its cost-effectiveness, bioremediation has become a promising strategy for C H removal. Contamination sites typically take on an anaerobic context, which complicates the energetics of contamination sites and is a subject that is scarcely broached in studies of Albertan sediments. This study examines the innate potential for indigenous microbial communities in Albertan sediments to remove C H in a multitude of reduced conditions. Community profiles of these sediments were analyzed by 16S rRNA gene amplicon sequencing, and removal rates and reaction stoichiometries were observed by gas chromatography and ion chromatography. Organisms belonging to known primary degrader taxa were identified, including Geobacter (iron-reducing), and Peptococcaceae (nitrate-reducing). Furthermore, benzene removal patterns of the cultures were similar to those observed in previously reported microcosms, with lag times between 70-168 days and removal rates between 3.27-12.70 µM d . Such information could support a more comprehensive survey of Albertan sediment consortia, which may eventually be utilized in informing future remediation efforts in the province.