Bioremediation of Hexanoic Acid and Phenanthrene in Oil Sands Tailings by the Microbial Consortium BioTiger™.

Polycyclic aromatic hydrocarbons (PAHs) and naphthenic acids (NAs) are toxic contaminants of environmental concern found in process water and mature fine tailings, or tailings, from the oil sands industry. BioTiger™, a patented microbial consortium of twelve natural environmental isolates, was found to cometabolically biodegrade the NA hexanoic acid and the PAH phenanthrene in the presence of tailings. Hexanoamide was found to be produced and consumed during cometabolism of hexanoic acid. Mechanistic analysis demonstrated three of the BioTiger™ strains generated biosurfactants with the bacterial adhesion to hydrocarbons assay, seven with the methylene blue active substances assay, and nine with a hemolysis assay. Serial transfers of the BioTiger™ consortium demonstrated the stability of hexanoic acid degradation over several generations. The results demonstrate that BioTiger™ cometabolically biodegrades combinations of phenanthrene and hexanoic acid in tailings. This work reveals the potential for in situ bioremediation of tailings with this natural microbial consortium.