"Microbial activity in petroleum reservoirs over geologic time has led to the biodegradation of most of the world’s oil reserves. Geochemical evidence for in situ biodegradation is strong, but little is known from a biological perspective and current micobiological understanding is largely inferred from non-oil field environments. Incorporating microbiology into petroleum geoscience and engineering will increase understanding and potentially allow better management of this vast energy resource. Microbial biomass in the deep subsurface is thought to be as large as on earth’s surface, yet our knowledge of this ‘Amazon’ beneath us remains currently almost zero. To better understand oil biodegradation, the microbiology of subsurface petroleum reservoirs will be investigated at Newcastle University by combining approaches in molecular biology, microbiology and biogeochemistry. Heavy oil samples will be obtained from the Athabasca tar sands in Western Canada. Nucleic acid and lipid analyses of in situ microbial communities will reveal the diversity and abundance of reservoir microbial groups. Efforts directed toward successfully cultivating indigenous reservoir microbes - a goal that has largely eluded petroleum microbiologists to date - will open doors for growth and physiology studies. Biogeochemical rate measurements (e.g., methane production) in tar sands-inoculated microcosms will enable linking specific organisms to important processes. We hypothesize that hydrocarbon-degrading consortia of syntrophic bacteria and methanogenic archaea will be important players. Alternatively, anaerobes that couple hydrocarbon oxidation to sulfate or iron reduction may also be important. A stronger microbiological understanding of these groups and their roles in situ will be key to developing sound heavy oil management strategies and future applications for upgrading of heavy oil into methane."