The shale gas basins in the Ohio-Pennsylvania-New York region contain the largest natural gas
reserves in the U.S. In 2012, over 7,000 Marcellus shale gas wells were active in Pennsylvania, and Ohio is
expecting a similar level of development in its deeper, Utica-Point Pleasant shale over the next 5 years.
These shale have insufficient permeability to produce natural gas at economical rates, thus their development
requires horizontal drilling coupled to hydraulic fracturing, or “fracking”. The hydraulic fracturing process
involves wellbore detonation and high-pressure injection of large volumes (up to 20 million L) of freshwater
and sand mixed with chemical additives to propagate fissures in the shale matrix, maximizing the surface
area for natural gas release to the wellbore. As a result of fracturing, larger flow paths and newly exposed
shale surfaces offer greater biogeochemical gradients for microbial colonization with greater opportunities
for nutrient and genetic exchange. We know little about the indigenous microbial membership of Marcellus
shale, but given current physicochemical conditions of this formation (depths > 1000m, pressures > than 50
MPa, temperatures > 60ºC, 20% salt content, and pore sizes < 1 µm) we anticipate that organisms enriched
during energy development will encode adaptations to these physical and geochemical conditions. Our
motivation is to understand the biotic and engineered factors responsible for alter Less...