蜡状芽孢杆菌对烟嘧磺隆的降解及降解产物2-氨基-4,6-二甲氧基嘧啶的环境生物毒性  

Degradation of nicosulfuron by Bacillus cereus and toxicity of the degradation product 2-amino-4,6-dimethoxy pyrimidine to environmental organisms

作　　者：党晶晶 杨冬臣 张哲[1] 王振梅 张金林[1] DANG Jingjing;YANG Dongchen;ZHANG Zhe;WANG Zhenmei;ZHANG Jinlin(College of Plant Protection,Agricultural University of Hebei,Baoding 071000,Hebei Province,China)

机构地区：[1]河北农业大学植物保护学院

出　　处：《农药学学报》2018年第5期652-660,共9页Chinese Journal of Pesticide Science

基　　金：国家自然科学基金项目(31471786)

摘　　要：为明确蜡状芽孢杆菌对烟嘧磺隆的降解及母体和降解产物对环境生物的毒性,采用超高效液相色谱-质谱（UPLC-TQD）联用法分析了蜡状芽孢杆菌对烟嘧磺隆的降解产物,同时参照＂化学农药环境安全评价试验准则＂方法,分别测定了烟嘧磺隆和主要降解产物2-氨基-4,6-二甲氧基嘧啶对斑马鱼、大型溞和斜生栅列藻3种水生生物的急性毒性。结果表明：经蜡状芽孢杆菌降解后,共检测到4种烟嘧磺隆的降解产物,分别为2-氨基-4,6-二甲氧基嘧啶（Ⅰ）、2-[N-（氨基甲基）氨磺酰基]-N,N-二甲基烟酰胺（Ⅱ）、2-[1-（4,6-二甲氧基嘧啶-2-基）脲基]-N,N-二甲基烟酰胺（Ⅲ）和N-（4,6-二甲氧基嘧啶-2-氨基甲酰基）-1-（甲基亚氨基）甲磺酰胺（Ⅳ）,其中2-氨基-4,6-二甲氧基嘧啶（Ⅰ）为主要降解产物,由此推测蜡状芽孢杆菌对烟嘧磺隆的降解主要是通过使其磺酰脲桥上C—N键、C—S键以及吡啶环断裂而实现的。毒性测定结果显示：烟嘧磺隆及主要降解产物Ⅰ对斑马鱼的96 h-LC50值分别为16.95和〉100.0 mg/L,其急性毒性等级均为＂低毒＂;两者对斜生栅列藻的72 h-ErC50值分别为8.070和142.7 mg/L,均为＂低毒＂;对大型溞的48 h-EC50值分别为9.190和51.95 mg/L,分别为＂中毒＂和＂低毒＂。研究表明,烟嘧磺隆经蜡状芽孢杆菌降解后,其主要降解产物对3种水生生物的毒性均明显降低。The degradation of nicosulfuron mediated by Bacillus cereus and the toxicity of nicosulfuron and its degradation products to environmental organisms were investigated.UPLC-TQD was used to analyze the degradation products.At the same time,the toxicity of nicosulfuron and its main degradation product to Brachydanio rerio（zebrafish）,Daphnia magna and Scenedsmus obliquus were determined according to＂chemical pesticide environmental safety evaluation test guidelines＂.The results showed that four degradation products,2-amino-4,6-dimethoxy pyrimidine（Ⅰ）,2-[N-（aminomethyl）sulfamoyl]-N,N-dimethylnicotinamide（Ⅱ）,2-[1-（4,6-dimethoxypyrimidin-2-yl）ureido]-N,N-dimethylnicotinamide（Ⅲ）and N-（4,6-dimethylformamide）oxypyrimidin-2-ylcarbamoyl）-1-（methylimino）methanesulfonamide（Ⅳ）,were detected.And 2-amino-4,6-dimethoxy pyrimidine was the main degradation product.It is speculated that the degradation of nicosulfuron mediated by B.cereus was proceeded via the C—N and C—S bond cleavage in the sulfonylurea bridge and the cleavage of the pyridine ring.The toxicity study showed that nicosulfuron and the degradation productⅠhad＂low toxicity＂to zebrafish,with the 96 h-LC50 values of 16.95 mg a.i./L and100.00 mg a.i./L,respectively.Then the ErC50 of nicosulfuron and the degradation productⅠagainst S.obliquus at 72 h were 8.070 and 142.7 mg a.i./L,respectively,which indicated＂low toxicity＂.The EC50 of nicosulfuron and the degradation productⅠagainst D.magna at 48 h were 9.190 and 51.95 mg a.i./L,respectively,and their toxicity levels were＂medium toxicity＂and＂low toxicity＂,respectively.In a word,the toxicity of the main degradation product to the three aquatic organisms were significantly reduced compared to nicosulfuron.

关 键 词：微生物降解 蜡状芽孢杆菌 烟嘧磺隆 降解产物 2-氨基-4 6-二甲氧基嘧啶 环境生物 毒性 

分 类 号：TQ450.26[化学工程—农药化工] X53[环境科学与工程—环境工程]