烟嘧磺隆降解菌枯草芽孢杆菌YB1颗粒剂的加工及应用

YB1是从农药厂污水中分离筛选得到的一株对烟嘧磺隆具有较好降解作用的枯草芽孢杆菌Bacillus subtilis。为探究YB1对土壤中烟嘧磺隆的降解能力，本研究对YB1固体发酵产物进行了颗粒剂加工，并对菌株载体和保护剂进行了筛选。优化后的YB1颗粒剂的加工方法为:将YB1固体发酵产物与载体活性白土按质量比1:1混合，加入质量分数为3%的保护剂酪氨酸和5%的淀粉进行挤压造粒，所得颗粒剂的有效活菌数为8.75×108 CFU/g。以小麦为指示植物，应用室内盆栽法研究了YB1颗粒剂对土壤中烟嘧磺隆的降解效果。结果表明，1 kg土壤中添加20 g YB1颗粒剂28 d后可将土壤中1 mg/kg的烟嘧磺隆降解至对小麦无明显药害水平。研究结果表明，YB1颗粒剂对含有烟嘧磺隆残留的土壤具有一定的修复能力。

Processing and application of nicosulfuron degrading bacterium Bacillus subtilis YB1 granules

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.