Processingandapplicationofnicosulfurondegradingbacterium<italic>Bacillussubtilis</italic>YB1granules

YB1 is a highly effective nicosulfuron-degrading Bacillus subtilis strain isolated from pesticide factory wastewater. In order to investigate the ability of YB1 to degrade nicosulfuron in the soil, the solid fermentation product of YB1 was used for granules processing, and the vector and protective agent of YB1 were screened during processing. The optimized formula of YB1 granules is as follows: solid fermentation product and activated clay (1:1 mass ratio) were mixed and extruded into granules, with adding tyrosine (mass fraction 3%), and starch (mass fraction 5%). The effective number of viable bacteria of YB1 granules was 8.75×10⁸ CFU/g. In addition, indoor pot experiment method was conducted to study the effect of YB1 granules on the remediation of nicosulfuron in soil, using wheat as a sensitive indicator plant. When the concentration of nicosulfuron was 1 mg/kg and the added granules in the soil were 20 g/kg, the concentration of nicosulfuron decreased to safe-level after 28 d. The results demonstrated that YB1 granules has the ability to remediate the nicosulfuron residue in soil.