通过Miseq高通量测序分析和荧光定量PCR技术,研究某纳污河流中四环素类与磺胺类抗性基因(ARGs)的分布特征、传播情况及微生物群落结构相关性.结果表明:在河流地表水与沉积物中均检测到四环素类抗性基因tetA和tetB与磺胺类抗性基因sul1和...通过Miseq高通量测序分析和荧光定量PCR技术,研究某纳污河流中四环素类与磺胺类抗性基因(ARGs)的分布特征、传播情况及微生物群落结构相关性.结果表明:在河流地表水与沉积物中均检测到四环素类抗性基因tetA和tetB与磺胺类抗性基因sul1和sul2,四环素类抗性基因和磺胺类抗性基因的绝对丰度分别为5.09×10^3~1.26×10^7,3.94×10^5~1.32×10^9copics/L,磺胺sul1抗生素抗性基因丰度显著高于其它基因;河流主要优势菌门为Proteobacteria,Bacteroidetes,Firmicutes,Actinobacteria和Cyanobacteria,其平均总相对丰度占总比例的95.62%,且总体差异较小.抗性基因与微生物群落冗余分析显示, Methylotenera菌属是影响tetA抗性基因分布丰度的主要因素, Dechloromonas和Clostridium sensu stricto 1菌属是影响tetB抗性基因分布丰度的主要因素,Dechloromonas、Clostridium sensu stricto 1和Methylotenera菌属是影响sul1、sul2抗性基因分布丰度的主要因素.展开更多
The gas phase reaction mechanism of Cl2 ＋ I2 = 2ICl has been theoretically investigated by DFF method at the B3LYP/3-21 G＊ level. Transition states of three reaction channels were consequently given. The results ind...The gas phase reaction mechanism of Cl2 ＋ I2 = 2ICl has been theoretically investigated by DFF method at the B3LYP/3-21 G＊ level. Transition states of three reaction channels were consequently given. The results indicate that in the title reaction the least activation energy of bi-molecular reaction was smaller than the dissociation energies of I2 and Cl2, and thus the reaction mechanism was the course of molecule-molecule interaction at low reaction rate. If other factors such as illumination were taken into account, I2 could dissociate into I atoms and then react with Cl2, or Cl2 dissociates into CI atoms and reacts with I2. These were photochemical reactions with high reaction speed. The theoretical results were further validated with absorbance measurement at 516 nm.展开更多
文摘通过Miseq高通量测序分析和荧光定量PCR技术,研究某纳污河流中四环素类与磺胺类抗性基因(ARGs)的分布特征、传播情况及微生物群落结构相关性.结果表明:在河流地表水与沉积物中均检测到四环素类抗性基因tetA和tetB与磺胺类抗性基因sul1和sul2,四环素类抗性基因和磺胺类抗性基因的绝对丰度分别为5.09×10^3~1.26×10^7,3.94×10^5~1.32×10^9copics/L,磺胺sul1抗生素抗性基因丰度显著高于其它基因;河流主要优势菌门为Proteobacteria,Bacteroidetes,Firmicutes,Actinobacteria和Cyanobacteria,其平均总相对丰度占总比例的95.62%,且总体差异较小.抗性基因与微生物群落冗余分析显示, Methylotenera菌属是影响tetA抗性基因分布丰度的主要因素, Dechloromonas和Clostridium sensu stricto 1菌属是影响tetB抗性基因分布丰度的主要因素,Dechloromonas、Clostridium sensu stricto 1和Methylotenera菌属是影响sul1、sul2抗性基因分布丰度的主要因素.
基金Project supported by the Chinese Postdoctoral Science Foundation (No. 2003033486)
文摘The gas phase reaction mechanism of Cl2 ＋ I2 = 2ICl has been theoretically investigated by DFF method at the B3LYP/3-21 G＊ level. Transition states of three reaction channels were consequently given. The results indicate that in the title reaction the least activation energy of bi-molecular reaction was smaller than the dissociation energies of I2 and Cl2, and thus the reaction mechanism was the course of molecule-molecule interaction at low reaction rate. If other factors such as illumination were taken into account, I2 could dissociate into I atoms and then react with Cl2, or Cl2 dissociates into CI atoms and reacts with I2. These were photochemical reactions with high reaction speed. The theoretical results were further validated with absorbance measurement at 516 nm.
