Phytoremediation: synergistic use of plants and bacteria to clean up the environment.

Phytoremediation is a relatively new approach to removing contaminants from the environment. It may be defined as the use of plants to remove, destroy or sequester hazardous substances from the environment. Unfortunately, even plants that are relatively tolerant of various environmental contaminants often remain small in the presence of the contaminant. To remedy this situation, plant growth-promoting bacteria that facilitate the proliferation of various plants especially under environmentally stressful conditions may be added to the roots of plants. These bacteria have been selected to lower the level of growth-inhibiting stress ethylene within the plant and also to provide the plant with iron from the soil. The net result of adding these bacteria to plants is a significant increase in both the number of seeds that germinate and the amount of biomass that the plants are able to attain, making phytoremediation in the presence of plant growth-promoting bacteria a much faster and more efficient process.