Monday, November 13, 2006

The Effects of an Endomycorrhizal Fungus Glomus mosseae on the Uptake of Lead by Vetiver Grass.

Summer Barber, Rupali Datta, and Dibyendu Sarkar. Univ of Texas, One UTSA Circle, San Antonio, TX 78249

In 2005, lead was named second on the CERCLA Priority List of Hazardous substances. In the San Antonio Area, lead has been identified as a major soil contaminant in many neighborhoods. The major source of lead contamination is lead based paint-contaminated older homes in the inner city. In addition, numerous public, private and military shooting ranges exist in San Antonio, which constitute another source of lead contamination. While it is imperative to find an environmentally friendly way to remediate these lead contaminated soils, current lead remediation technologies are very expensive. In recent years, phytoremediation has been identified as an inexpensive and environment-friendly method to cleanup lead contaminated soils. Vetiver grass (Vetiveria zizanioides) is a fast-growing, high biomass plant that has been identified as a hyperaccumulator of lead. However, in the presence of phosphorous in the soil, lead is precipitated as the mineral pyromorphite, making it unavailable for plant uptake. The microorganism, Glomus mossea, has shown the potential of solubilizing the lead mineral; therefore, increasing the bioavailability of lead for removal by the vetiver grass. A greenhouse study was executed to elucidate the ability of Glomus mossea to solubilize the lead mineral, and enhance the lead uptake of vetiver grass.