The present research project foresees the isolation and characterization of bacterial strains that can degrade the intermediates derived from the spontaneous degradation of sulfonylurea herbicides. These compounds are the most widely used post emergent herbicide for the control of annual and perennial weeds of rice fields and they are characterized by short half lives ranging from few days to eight weeks. In fact, several sulfonylurea herbicides undergo to spontaneous degradation which occurs at high rate in enviroments like rice fields charactérized by low pH conditions. Preliminary results obtained by us with cinsulfuron, a member of sulfonylurea herbicides, have shown that spontaneous degradation gives rise to the accumulation of two major intermediates. These two molecules, whose structure has not been yet de fined and whose ecotoxicity is totally unknown, are stable and accumulate in sterile and non sterile rice field water under laboratory conditions. Mineralization or complete biodegradation of an organic molecule in water and soil is almost always a consequence of microbial activity. The work programme foresees the isolation and characterization of bacterial strains that totally convert the organic intermediates of sulfonylurea spontaneus degradation to inorganic products. Such strains will be further selected for their inability to degrade the parental compound (e.g. sulfonylurea herbicides). On the basis of the acquired knowledge, it is then foreseen to characterize bacterial strains that may be suitable for bioremediation of herbicide treated areas without affecting the efficacy of the hérbicide itself.
Funding SchemeEAW - Exploratory awards