COMPARING HEAVY METAL TOLERANCES OF MIXED SPECIES BIOFILM AND PLANKTONIC MICROBIAL COMMUNITIES CULTURED FROM THE ALBERTA OIL SANDS PROCESS WATER

Since the industrial revolution, toxic metal pollution resulting from mining, drilling and hydraulic fracturing for fossil fuels (among other resources) has made toxic metal ions a far-reaching environmental pressure. The Alberta oil sands are the third largest oil reserve in the world, whose extraction process results in wastes containing heavy metal contaminants that can be toxic to the surrounding environment. The formation of biofilms by microorganisms has been proposed to protect bacterial populations from toxic metals. Some studies suggest that these microbes can bioaccumulate the metals, which serves to remediate the wastewater and provide an avenue for future processing and acquisition. This study investigates the heavy metal tolerance of a mixed species consortium (both planktonic and biofilm) grown from Alberta oil sands process water. Over 15 metals were tested using a minimal medium supplemented with two different carbon sources, glucose and yeast extract. The mixed species culture was compared to a single species reference strain, Cupriavidus metallidurans, which is known to be tolerant to heavy metal induced stress.