Reduced metribuzin pollution with phosphatidylcholine-clay formulations
Tomás Undabeytia1, Esther Recio, Celia Maqueda
1Institute of Natural Resources and Agrobiology (CSIC), Seville, Spain. undabeyt@irnase.csic.es
Background:
Metribuzin is a widely used herbicide that has been identified as a groundwater contaminant. In this study, slow-release formulations of metribuzin were designed by encapsulating the active ingredient in phosphatidylcholine (PC) vesicles and adsorbing the vesicles onto montmorillonite.
Results:
The maximum active ingredient content in the slow-release formulations was 246 g kg(-1) . Infrared spectroscopy results revealed that the hydrophobic interactions between metribuzin and the alkyl chains on PC were necessary for encapsulation. In addition, water bridges connecting the herbicide and the PC headgroup enhanced the solubility of metribuzin in PC. Adsorption experiments in soils were performed to evaluate the relationship between sorption and leaching. Funnel experiments in a sandy soil revealed that the herbicide was not irreversibly retained in the formulation matrix. In soil column experiments, PC-clay formulations enhanced herbicide accumulation and biological activity in the top soil layer relative to a commercial formulation. PC-clay formulations also reduced the dissipation of metribuzin by a factor of 1.6-2.5.
Conclusions:
A reduction in the recommended dose of metribuzin can be achieved by employing PC-clay formulations, which reduces the environmental risk associated with herbicide applications. Moreover, PC and montmorillonite are non-toxic and do not negatively affect the environment.
Related Concept Videos
Microbial Bioremediation of Pesticides
Microbial Bioremediation of Uranium
Bioplastics
Synthesis of Phosphatidylcholine in the ER Membrane
The major components of all eukaryotic cell...
Bioremediation
Microbial Bioremediation of Hydrocarbons


