زيست پالايي علف كش هاي سولفونيل اوره توسط برخي باكتري هاي زيست پالا

The increasing population growth an‎d the urgent need for food security have made the use of chemical herbicides an inseparable part of modern agriculture. Among them, sulfonylurea herbicides, such as sulfosulfuron, are widely used with high efficiency in weed control. However, the excessive use of these compounds, especially in regions such as Iran with higher than global average consumption, has led to the accumulation of their residues in agricultural soils, pollution of water resources, an‎d toxicity to sensitive crops (such as lentils). This toxicity includes reduced root an‎d shoot growth, an‎d impaired nutrient absorption, which endangers the sustainability of agricultural ecosystems. In response to this challenge, bioremediation, utilizing the biodegradation power of microorganisms, is proposed as a green an‎d sustainable solution.Bacteria, due to their great metabolic diversity, are able to degrade herbicides through different metabolic pathways. This research aimed to identify the bioremediation capacity of indigenous bacteria, whose ability to bioremediate pollutants such as oil, plastic an‎d heavy metals has been previously proven in the Biotechnology Laboratory of Bu Ali Sina University, in the degradation of sulfosulfuron. In this study, the ability of bacteria to degrade the herbicide sulfosulfuron was eva‎luated in laboratory culture media. Conventional tests to determine the minimum inhibitory concentration (MIC) an‎d minimum lethal concentration (MBC) were performed using the dilution series method, which showed that the selec‎ted bacterial isolates survived an‎d were able to grow even at high concentrations, indicating their resistance to the herbicide.In addition, enzyme tests were performed including measuring the activity of catalase, protease an‎d lipase enzymes in the presence an‎d absence of herbicide. The extent of herbicide degradation was measured in the one-eighth nutrient broth culture medium containing herbicide as a control sample an‎d bacterial herbicide as a treatment sample using high-performance liquid chromatography (HPLC). The results of HPLC analysis at a concentration of 50 mg / L of herbicide showed no significant degradation of sulfosulfuron by the selec‎ted Pmf isolate (no change in the corresponding peaks). To investigate the effect of bacteria on germination, a lentil seed germination test was performed.The findings showed that under the conditions of treatment with filtered extract of Pmf bacteria along with 50 mg / L herbicide, lentil seeds were unable to germinate, but when the seeds were primed with seven bacterial isolates an‎d then irrigated with 50 mg / L herbicide solution, we witnessed successful seed germination. While lentil seeds without priming with bacteria were unable to germinate at any of the herbicide concentrations. These results clearly indicate the vital role of the presence of bacterial cells themselves on the seed surface (priming) in reducing the toxic effects of sulfosulfuron an‎d inducing germination. The results obtained showed that Pmf bacteria can be a suitable bacterium for the bioremediation of sulfosulfuron herbicide.

مجيد طالبي , سنبل ناظري

اكبر علي وردي

ابوذر سورني , جهانگير خواجه علي