Diversity Of Halophilic Or Halotolerant Actinomycete In Dead Sea And Identification Of A Novel Genus

Phylogeny method was applied to study the microbiome distribution and composition ofactinomycetes around the Dead Sea area using strains isolated from the Dead Sea soilsamples as material. The salt tolerance characteristic of the culturable actinomycetes strainswas studied by salt tolerance and adaptation test. We also isolated some new actinomycetespecies and made identification of them using polyphasic taxonomy. The main results are asfollows:1. We isolated237actinomycetes strains from the Dead Sea area soil samples. The16SrDNA was sequenced and blasted in the database of EzBiocloud. The results showed that theisolated strains could be classified into27species and16genera and implied that there wereabundant of actinomycetes resource in the Dead Sea area. We found that the dominantbacterial community was Nocardiopsis of Nocardiopsaceae and Saccharopolyspora ofPseudonocardiaceae. And we also isolated many unknown actinomycetes species with thehighest similarity of16S rDNA between92%and97%, meaning that it was to study on theactinomycetes resource of the Dead Sea area and there may be new actinomycetes belongingto upper taxonomic status.2. The salt tolerance and salt adaption tests of the27strains showed that the testedstrains had different degree of halophilic to different kinds of salt and all of the actinomyceteswere addicted to mixed salt. except for strain194,205,271and369, all the other strains wereaddictive to Mg and addictive to Na actinomycete and were advanced or extreme halophilic.Strain194,229,271and369were Na halophilic actinomycetes and strain205was mutisalthalophilic actinomycete. The tested strains had different tolerance degree to different salt andhalophilic actinomycetes had high tolerance to all kinds of salts with a wide range. Almost ahalf of the tested strains could grow well in medium containing35%salt. The phenomenonimplied that these strains may have a higher tolerace to salt.3. The16S rDNA of strain AFM10251T was sequenced and blasted in the EzBiocloud.The similarity of16S rDNA sequence of strain AFM10251T and the most closely related typestrain Actinopolyspora erythraea YIM90600T was only92.40%and a stable seperate lineagewas formed in the N-J and M-L phylogenetic tree. The results of the morphology observation, physiology and biochemistry identification chemical test and molecular analysis suggestedthat the strain AFM10251T should be considered to be a new genus in the familyActinopolysporaceae and named as Halopolyspora alba gen. nov., sp. Nov.