PT02 Soil Toxicology and Risk Assessment
Exhibit Hall
8:00 AM - Tuesday, 11 November 2003
(PT035) Development of analytical techniques for environmental detection and quantification of the Bt toxin from corn (Zea mays).
Clark, B1, Belden, J1, Coats, J1, 1 Iowa State University, Ames, IA, USA
ABSTRACT- The use of Bacillus thuringiensis (Bt) delta-endotoxins, through expression in transgenic plants, has increased substantially in agroecosystems in recent years. As a result, concerns have been raised regarding the safety of these toxic proteins in the environment. Constructing an ecological risk assessment requires quantitative environmental exposure data, but this is severely limited by the lack of accurate and sensitive analytical methods to quantify Bt proteins in soil environments. Current chemical methods do not yield toxin measurements that correlate well with the levels detected by bioassay. The overall goal of this project is to optimize analytical methods that will allow accurate and sensitive quantification of Bt proteins in natural environmental matrices and lay the groundwork for measurement of other toxic proteins in the future. In the early stages, this goal will be accomplished by: 1) evaluating solvent systems for high extraction efficiencies, 2) evaluating solvent-extracted protein for analysis by immunoassay. Multiple organic solvents and combinations were examined and soil extraction efficiencies were measured using ELISA.
Key words: transgenic, Bacillus thuringiensis, analytical