| Halophilic actinomycetes from extremely hypersaline environments are an age-old microorganism. Therefore, they could adapt to the peculiar environment conditions and produce some unique gene types and natural active compounds. Extreme environmental microbe is a valuable source for knowing the mechanism of biodiversity and boosting the development of biotechnology industry. Extremophiles are some strategic biosources for the protection of intellectual property rights in novel technology field.To this day, culture-dependent microbe quantity, especially extremophiles are very little, which seriously restrict the exploitation and utilization of microbial source. Phylogenetic diversity of halophilic actinomycetes from hypersaline, arid and sterile environments in Lop Nur salt lake was investigated by using the culture-dependent and culture-independent methods and phylogenetic analysis based on16S rRNA gene sequences. So as to we impersonally know actinobacterial diversity and to deeply understand life phenomenon.As far as the result of culture-independent methods on actinobacterial diversity, some good results are detected in this study. Firstly, The results showed that there were abundant actinobacterial diversity in the sediment of Lop Nur salt lake. These clones belong to12genera in the Acidimicrobidae, namely Ilumatobacter, Saccharopolyspora, Streptomyces, Actinopolyspora, Kocuria, Streptomonospora, Streptosporangium, Amycolatopsis, Isoptericola, Nocardiopsis, Dietzia and Glycomyces. Secondly, abundant novel actinobacteria exit in the salt lake.58.82%clones sequences exhibited low similarity (＜97.0%) to other species of the Acidimicrobidae which represent novel actinobacteria taxa. Others (36.78%) exhibited lower similarity (＜92.0%) which formed some large distinct clades in phylogenetic tree of actinobacterial16S rRNA gene sequences among Phylum Actinobacteria, may represent some new suborder or new class. Finally, the most abundant and diverse clones were the Glycomyces (20.1%), Dietzia(16.13%), lsoptericola(10.3%) and Nocardiopsis(5.88%), not Streptomyces(1.47%). The results showed that there were abundant actinobacterial diversity and some unknown actionobacterial groups existed in hypersaline environments in the sediment of Lop Nur salt lake.These actinomycetes isolated from hypersaline Environments belong to18genera, namely Haloglycomyces, Streptomyces, Actinopolyspora, Glycomyces, Micromonospora, Streptomonospora, Saccharomonospora, Amycolatopsis, Nocardiopsis, Myceligenerans, Kocuria, Isoptericola, Prauserella, Brevibacterium, Saccharopolyspora, Verrucosispora, Nesterenkonia and Haloactinospora. Excitingly, eight novel strains ware isolated. In accordance with the principle of polyphasic taxonomy, a systematic study had been conducted on the taxonomy of six novel isolates. Phylogenetic analysis showed that strain YIM92370T, having lower16S rRNA gene sequence similarity of93.7%with the described species of this Glycomycetaceae, can be distinguished from representatives of other two genera Glycomyces and Stackebrandtia in the family. The novel genus and species Haloglycomyces albus gen. nov., sp. nov. were proposed, with strain YIM92370Tas the type strain of Haloglycomyces albus. On the basis of the polyphasic evidence, the strain TRM40136T should be designated as a novel species of the genus Actinopolyspora for which the name Actinopolyspora xinjiangensis sp. nov. In addition, three novel halotolerans actinobacteria species(Brevibacterium salitolerans, Glycomyces halotolerans and Amycolatopsis salitolerans) as well as one holaphilic species(Saccharopolyspora lacisalsi) were proposed.According to test result, five media (GFA、GW1、AGG、MM and GL3) can good to isolate actinobacteria of salt lake. But no medium is almighty. Accordingly, we should design and innovate more media or isolated methods to make better to know the life world. |
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