Bacteria capable of degrading organic contaminants within an aquifer include many species from a wide spectrum of genera, e.g. Pseudomonas, Corynebacterium, Bacillus, etc. In most cases, a mixture of bacterial strains is required to completely oxidize a complex organic contaminant. Each strain of an organism may target a specific compound, working together with other organisms to ultimately degrade each intermediate until complete degradation, also known as mineralization, occurs. Some bacterial cells consist of hydrophobic surfaces. This mechanism allows degradation of less-soluble substances, such as toxaphene.
All bacteria produce enzymes to aid the degradation process.
These enzymes, known as biosurfactants, act as natural soaps that induce hydrocarbon solubilization and microemulsion formation. This enables the bacteria to draw the pollutant into a water phase from soil surfaces. Via surface contact or biosurfactant-aided solubilization, bacteria can attack several forms of hydrocarbons. Attack can occur on free-phase droplets of the chemical, either as a film adsorbed onto minerals, or as globules held within the interstices of a matrix by capillary forces. Chemicals completely dissolved in the aqueous phase are more readily subject to attack.