Isolation And Screening Of Marine Actinomvcetes And Study On The Function Of Its Two-component Signal Transduction System

The diversity of microbial and its metabolites in nature provides the inexhaustible driving force to found the leading compounds and new drugs. Although most of the derived from secondary metabolites of actinomycetes, but as a lot of antibiotics appeared from actinomycetes, antibiotic resources of the secondary metabolites of terrestrial actinomycetes become increasingly scarce. On the other hand, the Drug-resistant bacteria is increasingly serious, Push the researchers looking for the rich resources of Marine microorganisms.The new structure of Marine actinomycetes’ active substances often containing halogen elements or disulfide bond structure, there is a new antibacterial targets, the resistance of tumor cells and inhibition of pathogenic bacteria is stronger,.It has become the focus of the study, and the special Marine environment such as high salt, high pressure, low temperature and low light gives Marine actinomycetes unique metabolic mode and regulation mode. A large number of studies have shown that two-component signal transduction system in regulating the synthesis of the secondary metabolites such as antibiotics play an important role, this topic is for the purpose of researching that the roles of TCSs in screening of strain and elucidating the regulatory mechanism of actinomycetes TCSs to provide reference for further studyIn our study, we totally obtained eight strains of actinomycetes from 44 under extreme conditions of soil samples. After comparing the results of 16 s rDNA preliminary classification we found that all of the eight actinomycetes strains belong to Streptomyces. six strains of these actinomycetes such as I1, SR14, M01, STZ2, K1,and TVG-purple can produce bioactive substances inhibited the growth of the indicator bacteria. Actinomycetes TVG-purple also can produce purple pigment which make the whole colony morphology purple and could be able to restrain the growth of the Helminthosporium maydis and red yeast.Then we use Streptomyces TVG - purple as the starting strain to build the cosmid gene library in E.coli, and by means of library hybridization and genetic sequencing to determine the final strains 19#F5, As the best research object.,4275/76 is located in the center position of 19#F5. we electricity its plasmid into E.Coli BW25113 / pIJ790 and through the PCR - targeting technology to knockout the gene 4275/76 to obtain mutant strains, then joint transfer with wild strains TVG--purple, to obtain the mutant strain TVG - purple (△) 4275/76.