Dissipation of Cry1Ac and its Toxicity to NT Aquatic Organisms

The rising adoption of Bt crops has raised public concerns on their effect to non-target organisms. Thus, a study was conducted to investigate the persistence of Cry1Ac protein in soil, sediment, and water, and its toxicity to non-target organisms.

The dissipation of the Bt toxin was well described using first order kinetics, with the half-lives ranging from 0.8 to 3.2, 2.1 to 7.6 and 11.0 to 15.8 d in soil, sediment, and water, respectively. It was also found that the degradation of microorganisms affected the dissipation of Cry1Ac toxin and high temperature accelerated the processes. Cry1Ac toxin was more toxic to the midge (Chironomus dilutes) than the amphipod (Hyalella azteca). While Cry1Ac toxin exhibited toxicity to the midges, there is insignificant risk of Bt proteins to aquatic non-target organisms because their actual concentrations in the environment were much lower than the amount needed to kill at least half of the samples.

The research article of this study was published at the October 23, 2013 issue of the Journal of Agricultural and Food Chemistry: http://pubs.acs.org/doi/abs/10.1021/jf403472j.