有机磷农药是目前环境中残留量最多的农药之一,对其残留量的检测及降解机制的研究对于环境污染及生态修复具有重要意义。微生物传感器由生物学元件与换能器构成,因具有成本低廉、易于微型化及选择性高等特点而被广泛应用于各种生化物质...有机磷农药是目前环境中残留量最多的农药之一,对其残留量的检测及降解机制的研究对于环境污染及生态修复具有重要意义。微生物传感器由生物学元件与换能器构成,因具有成本低廉、易于微型化及选择性高等特点而被广泛应用于各种生化物质的分析和检测。本文从长期受农药污染的土壤中分离出4株能以甲基对硫磷为碳源生长的菌株,根据形态特征和16S r RNA基因序列同源性分析,对4株降解菌进行鉴定,利用高效液相色谱测定降解率,选取降解率最高的1株菌进行降解机制研究,以期将其应用于测定环境中甲基对硫磷残留的电位型微生物传感器的构建。结果表明,在甲基对硫磷初始浓度50 mg·L-1、30℃、p H 7.0的培养条件下培养7 d,4株菌对甲基对硫磷的降解率均在78%以上,其中1株菌的降解效率可达100%。16S r RNA基因序列测定表明,该菌株属于克雷伯氏菌属,命名为Klebsiella sp.MP-6。利用液相色谱-质谱联用对其降解产物的研究表明,菌株MP-6水解甲基对硫磷主要产生二甲基硫代磷酸(dimethyl thiophosphoric acid,DMTP)和对硝基苯酚(p-nitrophenol,PNP),极少部分PNP通过产生4-硝基邻苯二酚(4-nitrocatechol,4-NC)和1,2,4-苯三酚(1,2,4-BT)进一步代谢。结果表明,基于测定中间产物对硝基苯酚(p-nitrophenol,PNP)的电位响应信号,该菌株适用于构建测定海水及土壤等环境中有机磷农药的微生物传感器。展开更多
The assembly reactions of o- (or m-, or p-) tetrafluorobenzenedicarboxylic acid (denoted as o-H2L, m-H2L and p-HzL, respectively), benzonitrile and Ag+ ion led to three compounds: [Ag2(PhCN)2(o-HL)2]n (1),...The assembly reactions of o- (or m-, or p-) tetrafluorobenzenedicarboxylic acid (denoted as o-H2L, m-H2L and p-HzL, respectively), benzonitrile and Ag+ ion led to three compounds: [Ag2(PhCN)2(o-HL)2]n (1), [Ag2(PhCN)2(m-HL)2]n (2) and [Ag2(PhCN)2(p-L)], (3). 1 and 2 feature a 1D coordination chain, while 3 bears a 2D net structure. A variety of weak interactions are observed in the compounds. Strong nwrinteractions connect the 1D chains into a 3D supramolecular network in 1. Hydrogen bonds connect the chains into layers in 2. Three types of interesting π-π interactions also assemble the 2D layers into a 3D overall structure in 3.展开更多
文摘有机磷农药是目前环境中残留量最多的农药之一,对其残留量的检测及降解机制的研究对于环境污染及生态修复具有重要意义。微生物传感器由生物学元件与换能器构成,因具有成本低廉、易于微型化及选择性高等特点而被广泛应用于各种生化物质的分析和检测。本文从长期受农药污染的土壤中分离出4株能以甲基对硫磷为碳源生长的菌株,根据形态特征和16S r RNA基因序列同源性分析,对4株降解菌进行鉴定,利用高效液相色谱测定降解率,选取降解率最高的1株菌进行降解机制研究,以期将其应用于测定环境中甲基对硫磷残留的电位型微生物传感器的构建。结果表明,在甲基对硫磷初始浓度50 mg·L-1、30℃、p H 7.0的培养条件下培养7 d,4株菌对甲基对硫磷的降解率均在78%以上,其中1株菌的降解效率可达100%。16S r RNA基因序列测定表明,该菌株属于克雷伯氏菌属,命名为Klebsiella sp.MP-6。利用液相色谱-质谱联用对其降解产物的研究表明,菌株MP-6水解甲基对硫磷主要产生二甲基硫代磷酸(dimethyl thiophosphoric acid,DMTP)和对硝基苯酚(p-nitrophenol,PNP),极少部分PNP通过产生4-硝基邻苯二酚(4-nitrocatechol,4-NC)和1,2,4-苯三酚(1,2,4-BT)进一步代谢。结果表明,基于测定中间产物对硝基苯酚(p-nitrophenol,PNP)的电位响应信号,该菌株适用于构建测定海水及土壤等环境中有机磷农药的微生物传感器。
基金Supported by the NNSFC (21071025,91122031, 21107008)Doctoral Fund of Ministry of Education of China (20100041120021)the Fundamental Research Funds for the Central Universities (DUT12YQ04)
文摘The assembly reactions of o- (or m-, or p-) tetrafluorobenzenedicarboxylic acid (denoted as o-H2L, m-H2L and p-HzL, respectively), benzonitrile and Ag+ ion led to three compounds: [Ag2(PhCN)2(o-HL)2]n (1), [Ag2(PhCN)2(m-HL)2]n (2) and [Ag2(PhCN)2(p-L)], (3). 1 and 2 feature a 1D coordination chain, while 3 bears a 2D net structure. A variety of weak interactions are observed in the compounds. Strong nwrinteractions connect the 1D chains into a 3D supramolecular network in 1. Hydrogen bonds connect the chains into layers in 2. Three types of interesting π-π interactions also assemble the 2D layers into a 3D overall structure in 3.