Expression Of CadR Protein On Pseudomonas Aeruginosa And Its Application In Water And Soil

In this paper,Pseudomonas aeruginosa in the Pseudomonas was used as a carrier for the first time,and a heavy metal binding protein CadR with specific response capacity to cadmium ions was displayed on the surface by molec?Lar biology techniques.The expression of CadR protein confers excellent cadmium ion adsorption capacity to Pseudomonas aeruginosa.This adsorption capacity is specific to cadmium ions,and engineering bacteria have no adsorption ability to other heavy metal ions,b ut low concentrations of other ions do not interfere with engineering.The engineered bacteriaused the method of random insertion of the suicide plasmid pBAM1 into the genomic genome of Pseudomonas aeruginosa,which confers excellent genetic stability to engineered Pseudomonas aeruginosa,an application of this stability to engineered bacteria,It is very important for practical application to engineered bacteria.We also investigated the effect of temperature and pH on the cadmium ion adsorption capacity of the engineered bacterium.It was found that the cadmium ion adsorption capacity of the engineered bacterium at 30°C and pH=7 reached the best state.In this study,we conducted a laboratory-scale engineering application of Pseudomonas aeruginosa in soil cadmium contamination remediation experiments.The experimental results show that the current construction of engineering bacteria in natural soil samples is generally effective,but after sterilization.The natural soil shows a certain fixed effect,indicating that the engineered bacteria are not dominant in the competition with indigenous microorganisms.The success of this paper provides us withsome guidance on genetic engineering applications of Pseudomonas aeruginosa.We first expressed the heavy metal binding protein on the s urface of Pseudomonas aeruginosa,indicating that Pseudomonas aeruginosa can express exogenous heavy metal binding protein,which provides a theoretical basis for the f uture application of Pseudomonas aeruginosa in this area,but in practice Soil remediation results show that the engineered bacteria are not suitable for practical soil remediation,which provides us with guidance: Ordinary pure-breeding Pseudomonas aeruginosa may not be applicable with soil remediation,in future studies,we can get from the soil Isolation of a bacterium having a certain adsorption capacity for cadmium ions and occupying a dominant position in the soil microbial population,and expression of the CadR protein on its surface,that is,It is possible to obtain a strain with strong cadmium ion adsorption capacity,and it can occupy the advantage in the competition of soil microorganism without affecting the adsorption capacity of cadmium ion.