The Analyse Of Nif Genes Mutation In Genomes Of Desert Oligotrophic Bacteria By Low-energy N~+ Implantation

At present,with the global soil erosion,land desertification is becoming increasingly serious,the sand method of efficient,convenient and fast will become crucial.Oligotrophic Bacteria can produce biological crusts found in China,Xinjiang Gurbantunggut Desert,the Oligotrophic Bacteria can be made into biological agents sprayed on the surface of sand,the formation of biological crusts,plays a fixing role.But this crust is easily destroyed and a short time is difficult to repair,in order to obtain the oligotrophic Azotobacter more efficient,the mutation of desert Oligotrophic Bacteria gene mediated by the comprehensive study of the low-energy N+ implantation.Based on De novo sequencing of bacterial genome research,is studied in this thesis from 5 aspects respectively using 6 kinds of bioinformatics methods 3 low-energy N+ Implantation Mutation and evolution of 7 gene mediated by recombinant DOB were obtained by the analysis and discussion of the nif gene mutation,a molecular structure the phylogenetic tree,one-level and secondary structure of protein and the change of the domain.The study found that all mutations in nif gene are "mutation hot spots",which shows that the area of the base of low energy nitrogen ions are more sensitive to radiation,mutation is the main driving force of biological evolution;nif gene recombinant strain DOB981 is different from the recombinant strains DOB113,DOB073 and the control strain DOB150,and its evolution faster than DOB113 and DOB073,provides a useful reference for the future study of people DOB strain for millions of years.The study on the structure of the nif protein showed that changes only the nifA and nifM gene encoding protein structure,mainly in the transmembrane region of the protein and transmembrane direction,provide the structural basis for the study of protein folding,spiral,crimp.In the protein secondary structure,recombinant strain DOB981 nif H,nifA,nifM,nifS(I,II,III)level two changes of protein structure and fixB occurred,laid the foundation for the study of the relationship between spatial structure and its catalytic function for the protein of nitrogenase.Domain protein plays a key role in the evolution of protein molecules,affect protein function expression,found that changes of protein domain nifH II recombinant strain DOB981,evolutionary mechanism is helpful to further clarify its protein.This paper through the injection of biological nitrogen fixation gene mediated by recombinant DOB bacteria to low-energy N+(nif gene)research,leading to its biological nitrogen fixation gene mutation and the molecular mechanism of bacterial evolution of DOB ion implantation on the molecular level,enrich the low-energy ions and related organisms function theory,for people to understand the biological nitrogen fixation gene mutation provides a rich material and evolution,and has important theoretical significance and practical value of molecular breeding and application of DOB.