Oleophilic bacteria, or Oil Eating Microbes (OEMs) are strains of bacteria that naturally use oils in the environment as their food source.
Remediation is defined as any process used to make the environment safe by absorbing, destroying, neutralizing or making harmless contaminants or decreasing them to acceptable levels. Bioremediation is the process of using microbes to decompose hazardous substances (such as oil) to their basic, non-toxic elements.
Every year approximately 100 million US gallons of oil spill into the environment. The biggest spill ever occurred during the 1991 Persian Gulf war when about 240 million gallons spilled from oil terminals and tankers off the coast of Saudi Arabia. The second biggest spill occurred over a ten-month period (June 1979 - February 1980) when 140 million gallons spilled at the Ixtoc I well blowout in the Gulf of Mexico near Ciudad del Carmen, Mexico.
After the Exxon Valdez accident at Bligh Reef in the spring of 1989, scientists and concerned environmentalists worked tirelessly on the beaches of Prince William Sound, Alaska to clean the 11 million gallons of spilled oil from animals, rocks, and the surrounding area. Fortunately for the environment, there were also billions of other tiny “workers” busy ridding the water and beaches of the thick, black oil.
Oil is made up mostly of hydrocarbons, which OEMs consume. The basic process of cleaning up an oil spill involves applying a special OEM-containing solution to the spill. First, the solution breaks down the oil to molecule size, thus increasing the surface area. The increase in surface area begins the oxygenation process; this revives dormant microbes so they will begin feeding on the hydrocarbons. Nutrients in the OEM solution help these activated microbes survive.
There are three basic types of hydrocarbons, straight chains, branched chains, and 6-member rings. The OEMs break down all three of these hydrocarbons into fatty acids or carboxylic acid, which are then further broken down for energy and carbon atoms, which then are used in the citric acid cycle to generate energy. Thus, oil is broken down into basic, nontoxic elements - carbon, carbon dioxide, and water.
In order to survive, OEMs require air, water, and a source of nutrients such as oil. In order to work successfully for bioremediation, OEMs need an environment with a temperature of –2 to 60°C, and a pH of 5.5-10. Other factors that can inhibit the success of OEMs in bioremediation are lack of oxygen, moisture, or mineral nutrients, as well as detrimental concentrations of waste. Once these factors are corrected, OEMs can begin to do their work.