苯胺类除草剂二甲戊灵降解菌的筛选，降解特性及代谢的研究

发布时间：2018-12-11 01:39

【摘要】：二甲戊乐灵(N-(1-乙基丙基)-2,6-二硝基-3,4-二甲基苯胺;CAS no.40487-42-1)是一种二硝基苯胺类除草剂。二甲戊灵的作用机制是通过二甲戊灵进入植物体内与微管蛋白结合,抑制植物细胞的分裂和伸长。近年来被广泛应用于玉米、马铃薯、水稻、大豆、烟草、蔬菜等多种作物的除草。它的广泛使用导致在土壤、地下水、地表水和空气中被检测出来,对生态系统和人类健康产生了重大的危害。本实验室从南海近海岸底泥中筛选到两株二甲戊灵降解菌,命名为WL-4和WL-6。通过形态学、生化特征、16S r DNA序列鉴定,WL-4鉴定为假单胞菌属(Pseudomonas sp.WL-4),WL-6鉴定为芽孢杆菌属(Bacillus sp.WL-6)。菌株Pseudomonas sp.WL-4最适p H和温度分别是7,30℃;菌株Bacillus sp.WL-6最适p H和温度分别是6,35℃。Haldane Andrews模型描述在不同底物浓度下,二甲戊灵的降解速率。降解速率常数qmax,Ks和Ki被拟合分别为0.02873h-1,5.629mg/L,240.2 mg/L。在菌株Bacillus sp.WL-6降解二甲戊灵过程中,通过气相色谱质谱联用仪(GC-MS)有九个产物被捕捉和鉴定。二甲戊灵通过羟基化形成2-((3,4-二甲基-2,6-二硝基苯基)氨基)丁-1-醇再通过脱烷基形成1-(5-甲基-7-硝基-1H-苯并[d]咪唑-1-基)丙-1-酮。二甲戊灵侧链的甲基先通过加氧酶形成羟基,然后在脱氢酶作用下生成7-氨基-5-甲基-1-(戊-3-基)-1H-苯并[d]咪唑-6-甲醛。细菌Bacillus sp.WL-6呈现了一个二甲戊灵全新的降解途径。而Pseudomonas sp.WL-4有两个产物被捕捉并被鉴定为为1-(5-甲基-7-硝基-1H-苯并[d]咪唑-1-基)丙-1-酮,和7-氨基-5-甲基-1-(戊-3-基)-1H-苯并[d]咪唑-6-甲醛。因此Pseudomonas sp.WL-4和Bacillus sp.WL-6可潜在用于二甲戊乐灵污染水体和土壤的生态修复。
[Abstract]:Penicillin (N- (1-ethyl propyl)-2-nitro-3-dimethylaniline; CAS no.40487-42-1) is a herbicide of dinitroaniline. The mechanism of penicillin is to inhibit the division and elongation of plant cells by entering the plant with tubulin binding. In recent years is widely used in maize, potatoes, rice, soybean, tobacco, vegetables and other crops weeding. Its widespread use has led to the detection of soil, groundwater, surface water and air, posing major risks to ecosystems and human health. Two strains of dimethopentyl degrading bacteria, named WL-4 and WL-6., were isolated from the sediments of the South China Sea near the coast in our laboratory. According to morphological and biochemical characteristics, 16s r DNA sequence, WL-4 was identified as Pseudomonas (Pseudomonas sp.WL-4) and WL-6 as Bacillus (Bacillus sp.WL-6). The optimum pH and temperature of strain Pseudomonas sp.WL-4 were 730 鈩，

本文编号：2371615