Team:PEA Exeter NH/Project

Fracking, or hydraulic fracturing, is a process by which highly pressurized liquid is used to create hairline fractures in rocks, particularly shale. Water, natural gas, brine, petroleum and other fluids then migrate into the well via the fractures, where it is harvested and refined into the natural gas and petroleum that we use everyday. Fracking has gained popularity due to its ability to extract deposits that were previously unreachable. Worldwide, there are more than 2.5 million fracking jobs. However, this method of extraction comes at a price. The fractures created during the fracking process could act as a conduit for petroleum and natural gas to migrate into groundwater. This intrusion affects both the environment due to lake and pond contamination and human health due to drinking water contamination.The hydrocarbons associated with petroleum and natural gas are often very difficult to detect in drinking water, making the consequences of groundwater contamination even greater. Additionally, new studies have linked fracking with the presence of radium in water runoff. Current laws require only infrequent testing for radioactivity in public drinking water systems. Therefore discovery of the contamination before widespread consumption of the radioactive water is unlikely. Exposure to radium can result in anemia, cataracts, cancer, and death. Therefore rapid detection of hydrocarbon as well as radiation contaminants is crucial.

Our team's goal is to produce bacteria that can detect toxic runoff and break down poisonous hydrocarbons. To that end we are using a catechol breakdown gene that will convert catechol into a yellow waste product, allowing contamination to be easily visualized. In addition, we are transforming the bacteria with a naphthalene breakdown gene that will first convert naphthalene to salicylate, and then convert the salicylate to catechol. We will also transform the bacteria with a cell damage promoter (that can be activated in the presence of radiation) attached to a downstream element coding for a blue colored protein. In order to outline a means of detection for each, we shall review the chemical properties of our contaminants: catechol and naphthalene.

Catechol (molecular formula C6H6O2), pyrocatechol or 1,2-dihydroxybenzene, is a toxic chemical that can cause depression of the central nervous system in large doses. In addition, it is classified by the International Agency for Research on Cancer as possibly carcinogenic to humans. As a result, our team intends to detect and eliminate catechol using the xylE gene that encodes catechol-2,3-dioxygenase. This enzyme catalyzes the transformation of catechol to a bright yellow product, allowing us to visually confirm the presence and elimination of catechol."

Naphthalene (molecular formula C10H8) is a toxic hydrocarbon found in crude oil. When ingested, naphthalene is known to cause potentially fatal hemolytic anemia, in which red blood cells are destroyed, affecting the body’s ability to transport oxygen. In addition, naphthalene can induce jaundice, tachycardia, and convulsions. Naphthalene can potentially leak from sites of fracking into groundwater. In order to combat this public health threat, our team intends to transform E. coli with a gene that will induce the degradation of naphthalene. In order to effectively detect naphthalene, we rely on its biochemical relationship to catechol.