Vertical movement in soil of insecticidal Cry 1Ab protein from Bacillus thuringiensis
Authors: Saxena, D., Flores, S., Stotzky, G.
Journal, Volume, Year: Soil Biology and Biochemistry, volume 34:111-120, 2002
Artificially prepared soil columns were amended with two clays (Montmorillonite and Kaolinite) and used to examine movement of Bt protein through soil. Protein sources were purified microbially-produced protein, growing seedlings (40 days) and plant biomass. In the studies using transgenic sources of protein (biomass and growing plant), only one level of clay amendment was used. The study showed decreased detection of protein in leachate with increasing clay composition.
No leaching was seen after 24 hours. This is interesting due to reports of short persistence times for the protein (by some authors). Protein was quantified using the Lowry method to measure protein, which is an indirect way to quantify the Bt portion. Authors say that the protein leaches in this study, but say it absorbs in other studies. While it can obviously do either under the right conditions, it is probably inaccurate to characterize the protein as likely to stick to soil AND likely to leach through soil.