Abstract: A process for the biological treatment of bitumen froth tailings produced from a tar sands treatment and bitumen froth extraction process is disclosed. In this process bitumen froth tailings, containing native hydrocarbon metabolizing microorganisms, are mixed with a growth media to form an inoculum which is then incubated under isothermal conditions for an amount of time to produce a mixed bacterial culture containing bioliquor and a water product containing a reduced amount of asphaltenes as well as solids such as clays and sands. The bioliquor produced in this process is then utilized in the initial tar sands conditioning process from which bitumen froth is produced as well as in the initial tar sands mining process via bioliquor injection directly into the tar sands formation. Because the mixed bacterial culture is made up of a number of hydrocarbon metabolizing microorganisms, the bioliquor is also used in the degradation of the asphaltenes.