A novel actinomycete, strain 1_25(T), was isolated from soil under a black Gobi rock sample from Shuangta, PR China, and characterized using a polyphasic taxonomic approach. The results of comparative analysis of the 16S rRNA gene sequences indicated the 1_25(T) represented a member of the genus Streptomyces. Chemotaxonomic data revealed that 1_25(T) possessed MK-9(H-8) as the major menaquinone. The cell wall contained LL-diaminopimelic acid (LL-DAP) and the whole-cell sugar pattern consisted of ribose, glucose and galactose. Major fatty acid methyl esters were observed to be iso-C-16:0 (23.6%), and anteiso-C-15:0 (10.4%). The genomic DNA G+C content of 1_25(T) was 69 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequence indicated that 1_25(T) had high sequence similarity with Streptomyces qinglanensis 172205(T) (98.1%), Streptomyces lycii TRM 66187(T) (98 %), and Streptomyces griseocarneus JCM4580(T) (98 %). In addition to the differences in phenotypic characters, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between 1_25(T) and closely related species were below the recommended threshold values for assigning strains to the same species. The fermentation product of 1_25(T) in ISP2 had an inhibitory effect on Staphylococcus aureus. On the basis of these genotypic and phenotypic characteristics, strain 1_25(T) (=JCM 34936(T)=GDMCC 4.216(T)) represents a novel species of the genus Streptomyces, for which the name Streptomyces gobiensis sp. nov. is proposed.
Gram-stain-negative, aerobic, rod-shaped, non-motile bacterium strain ZFBP2030(T) was isolated from a rock on the North slope of Mount Everest. This strain contained a unique ubiquinone-10 (Q-10) as a predominant respiratory quinone. Among the tested fatty acids, the strain contained summed feature 8, C-14:0 2OH, and C-16:0, as major cellular fatty acids. The polar lipid profile contained phosphatidyl glycerol, phosphatidyl ethanolamine, three unidentified phospholipids, two unidentified aminolipids, and six unidentified lipids. The cell-wall peptidoglycan was a meso-diaminopimelic acid, and cell-wall sugars were ribose and galactose. Phylogenetic analyses based on 16S rRNA gene sequence revealed that strain ZFBP2030(T) was a member of the genus Sphingomonas, exhibiting high sequence similarity to the 16S rRNA gene sequences of Sphingomonas aliaeris DH-S5(T) (97.9%), Sphingomonas alpina DSM 22537(T) (97.3%) and Sphingomonas hylomeconis CCTCC AB 2013304(T) (97.0%). The 16S rRNA gene sequence similarity between ZFBP2030(T) and other typical strains was less than 97.0%. The average amino acid identity values, average nucleotide identity, and digital DNA-DNA hybridization values between strain ZFBP2030(T) and its highest sequence similarity strains were 56.9-79.9%, 65.1-82.2%, and 19.3-25.8%, respectively. The whole-genome size of the novel strain ZFBP2030(T) was 4.1 Mbp, annotated with 3838 protein-coding genes and 54 RNA genes. Moreover, DNA G + C content was 64.7 mol%. Stress-related functions predicted in the subsystem classification of the strain ZFBP2030(T) genome included osmotic, oxidative, cold/heat shock, detoxification, and periplasmic stress responses. The overall results of this study clearly showed that strain ZFBP2030(T) is a novel species of the genus Sphingomonas, for which the name Sphingomonas endolithica sp. nov. is proposed. The type of strain is ZFBP2030(T) (= EE 013(T) = GDMCC 1.3123(T) = JCM 35386(T)).
Ecosystems away from human disturbance provide an ideal paradigm for microbial ecology research. The Burqin glacier No. 18 in the Chinese Altay Mountains is such an ecosystem; however, there are no prior studies on the microbiology in the area. Here, we isolated 902 bacterial strains on the Burqin glacier No. 18 to determine the diversity and distribution characteristics of microorganisms. Isolated strains belonged to six phyla (in the order of dominance: Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and Deinococcus-Thermus) and 90 genera. Our results also demonstrated the presence of a high proportion of potential new species (43%) in the Burqin glacier No. 18, and 67% of the potential new species were isolated at 25 degrees C. Species diversity varied among habitats, with the lowest diversity in surface ice and the highest diversity in the soil farthest from the glacier terminus. The pigmented colonies made up 52.7% of all isolates, with yellow-colored colonies being the most abundant (18.8%). This study indicates that the Burqin glacier No. 18 hosts rich bacterial strain diversity, and may represent a significant potential source of new functional and pigmented bacteria for the development of critical pharmaceuticals.