Screening The Activity Of Siderophore From Halophilic Actinomycetes And Preliminary Study On Functional Genes Of Active Stains

Actinomycetes as a precious species microorganism resource,has shown extraordinary application prospects in the field of biomedicine.Now,antibiotics on the market account for 60% of the secondary metabolism of actinomycetes.Due to the constant excavation of actinomycete resources in the general environment,the reproducibility of natural products obtained has increased repetitivly.So,the scientists have turned their attention to the actinomycete resources of extreme environments.The high-salt environment is an extreme environment in which the actinomycete resources are constantly being tapped,and their value is constantly reflected.As an essential resource for the growth and reproduction of microorganisms,iron ions occupy an irreplaceable position in the ecological environment.In the environment,siderophore compounds that can chelate ions,this kind compounds are considered as powerful weapons to compete for resources in microorganisms.At the same time,these compounds show great application prospects in the fields of biomedicine and environmental remediation.In the previous work of this study,compared to the general environment(about 50%),the number of strains with iron-producing carriers of halophilic actinomycetes was high(>90%),and the chelation ability of iron ions was relatively stronger.These experimental data precisely show that in the high-salt environment,the ecological status of halophilic actinomycetes is relatively special and has a good research space.In this study,firstly,explored and improved the separation method of halophilic actinomycetes.By adding different substrate substances to the isolation medium,and different nitrogen elements,siderophore chelators to study the different result.As a result of differert methods,315 strains of halophilic actinomycetes were isolated from the soil samples from the Salt Lake of Qijiaojing in Xinjiang province.In addition,before this work,a large number of functional genes of halophilic actinomycetes were studied.For this experiment,134 strains of halophilic actinomycetes with multiple functional genes were selected and incorporated into this study.In total,449 strains of halophilic actinomycetes were tested for the ability to produce siderophore compounds.Through the preliminary experiments,comprehensive comparison the double-layer plate method and the shaker fermentation method,we found that for the halophilic actinomycetes whether pioduce the siderophore,the inversion method is deemed the most convenient and most efficient screening method.Through the activity detection of siderophore,it was found that 315 strains of halophilic actinomycetes,which accounted for about 90% of the total number of bacteria,and the functional genes of various types of 134 high-throughput screening accounted for 97%.Considering that the high-throughput screening of multiple functional genes is more valuable for the study,the positive strains with multiple functional genes were only rescreened during the screening of positive strains.The screening results showed that the metabolites of 40 strains of halophilic actinomycetes exhibited high iron ion chelating ability.Secondly,three species of potential new halophilic actinomycetes were identified by polyphasic taxonomy.After identification,strains YIM 96934 and YIM 96448 were new species of Phytoactino polyspora,and YIM 96095 was a potential new science.Finally,8 dominant strains were selected from 40 strains of halophilic actinomycetes which were better in the rescreening process.Genome sequencing analysis was performed on them.