[Genetic analysis of the br gene in halophilic archaea isolated from Xingjiang region].

ABSTRACT

Some novel members of extremely halophilic Archaea, strain AJ11, AJ12 and AJ13, were isolated from Aularz Lake located in Altun Mountain National Nature Reserve of Xinjiang Uygur Autonomous Region in China. Partial DNA fragments encoding a bacteriorhodopsin (BR) as well as for 16S rRNA of isolated strains were amplified by PCR and their DNA sequences were determined subsequently. On the basis of homology and phylogenetic analysis about 16S rDNA, it was considered that the isolated strains formed a microbiological population are the members of genus Natrinema. The results of genetic analysis, such as GC content, transition/transversion (Ti/Tv) rate ratios, synonymous substitution rates (Ks), indicated that the br fragments with high level of genetic divergence are faced with both purifying selection and bias mutation pressure. The study provides the base for using of species and BR proteins resources.