Phylogenetic And Physiological Diversity Of Actinomycetes Isolated From Different Habitats In Qinghai-Tibet Plateau

Ten soil samples were collected from5representative boreholes in the northern part of Gerze County in Qinghai-tibet plateau.56actinomycetes were isolated using two mediums and the taxonomic status of the isolates was established according to their morphological characteristics in combination with full16S rDNA sequencing. The result revealed that all of the isolates belonged to Streptomyces spp. All of the56streptomycetes were subjected to antimicrobial and physiological tests, and the results showed that11strains had antimicrobial activity towords target pathogens,37stains produced H2S,20strains produced organic acid,56isolates produced catalase,12strains produced esterase I (Tween-20),45strains produced esterase Ⅱ (Tween-40),30strains produced esterase Ⅲ (Tween-80),24strains produced amylase,38strains produced proteinase, and32strains produced urease. These findings suggested that the diversity and richness of the secondary metabolites produced by streptomycetes isolated from permafrost region of Qinghai-tibet plateau may pave a way for bioprospecting towards Qinghai-tibet plateau.A total of87actinomycetes were isolated from rhizosphere soils of16plants collected from Qilian Mountain tiger ditch with different vegetations at different altitudes,using glycerin arginine agar media. Full16S rDNA sequencing in combination with morphological characteristics revealed that the isolates were classified into Streptomyces、Nocardia and a potential new isolate, with Streptomyces strains to be the dominating isolates constituting94.3%of the total counts of actinomycetes. All of the87actinomycetes were subjected to antimicrobial and physiological tests, and the results indicated that the lipase Ⅰ; lipase Ⅱ, lipase Ⅲ amylase, proteinase, urease, catalase, organic acid, H2S and diffusible pigment producing strains accounted for43.7%,81.6%,55.2%,52.9%,58.6%,65.5%,90.8%,19.5%,51.7%and31%of the total actinomycetes, respectively;29strains exhibited antimicrobial activity, accounting for33%of the isolates. The results of diversity and physiological activity indicated that the plant rhizosphere soil of Qilian Mountain is still a potential source for new actinomycetes and their novel bioactive compounds.