The Diversity Analysis And Polyphasic Taxonomy Of Halophilic Archaea In Lop Nur

The salt lakes in our country are rich in microorganism resources,and unique species diversity were created by the unique geographical environment.Under these environment stress,special physiological mechanism,art gene and metabolic type were appeared in microorganism and it laid a good foundation for human to realize the phenomenon of life.By far,only 1%microorganism kinds were found and the species was more scarce in the special environment.For further enriched the diversity of salt lakes in Xinjiang,soil samples were collected from the typical characteristics salt Lake Lop Nur.Halophilic archaea were isolated and their diversity were studied.The taxonomy of the new species were fixed through multiphase classification analysis.Chitosan-asparagine medium(F6),Glycerin-aspartic acid medium(C1),Mannitol-acid hydrolysis of casein medium(GWI),Trehalose-creatine medium(B7),Glycerin-arginine medium(GJ),Mannitol-alanine medium(Z5),Casein-mannitol medium(CMKA),CM,HP,and KC medium with different salinities were used for seperating archaea.Morphological characteristics identification,16S rDNA genes amplification,restriction endonuclease digestion to eliminate duplicate and 16S rDNA genes sequencing analysis were used for discussing the diversity of archaea.Finally 71 archaeal strains were obtained,which all belonged to Euryarchaeota,Halobacteria,Halobacteriales,Halobacteriaceae,and distributed in Haloterrigena,Natrialba,Halococcus,Halorubrum,Halovivax,Natrinema,Natronococcus,Halobiforma,Halopiger,Halostagnicola,Haloferax.Haloterrigena was the dominant group.The similarities between detected sequences(34%of total strains)and published sequences were less than 98%.They formed distinct clades in phylogenetic tree and might represent new taxa.Chitosan-asparagine medium(F6),which had a good isolation effect,was diluted to 1/2?1/10 and 5%?10%?15%?20%?25%?30%were set to isolate archaea strains.Another 19 archaeal strains were obtained,which all belonged to Euryarchaeota,Halobacteria,Halobacteriales,Halobacteriaceae,and distributed in Haloterrigena,Natrialba,Halopiger,Halostagnicola,Halovivax,Natrialba,Natronorubrum.Haloterrigena was the dominant group.The similarities between detected sequences(19%of total strains)and published sequences were less than 98%.They formed distinct clades in phylogenetic tree and might represent new taxa.At the same time,as the increase of the dilution,the obtained strains reduced.And as the increase of the NaCl concentration,the richer of the medium,the more strains were obtained.It reached the max at the 20%.Three potential new species were chosen to fix the taxonomy through the traditional classification of phenotypic characteristics,genotype analysis and chemical composition analysis and so on.The results showed that the three archaea strains were three new species in a new genus named Natribaculum.And TRM20010T named Natribaculum breve,TRM20040T named Natribaculum alaerense,TRM20345T named Natribaculum longum respectively.In this study,90 archaea strains were obtained through designing 10 appropriate separation mediums,introducing nutrition dilutions,simulating the growth environment and setting 6 different NaCl concentrations.All of these showed the rich archaea resources in LopNur,which contained a variety of new types of species and had great research value.Other,the research showed that the growth of microorganism were limited not only by the growth environment,nutrition,temperature,pH and NaCl concentration,but also the separation medium.Combining the diversity of the soil sample from different environments,more microbial resources would be obtained and the diversity of life on earth would be revealed better.