Mucilaginibacter aurantiaciroseus sp. nov. and Mucilaginibacter flavidus sp. nov., isolated from Renlongba glacier on the Tibetan Plateau.

Strains RB4R14 and RT5R15, two Gram-stain-negative, aerobic, rod-shaped, non-motile bacteria, were isolated from ice and cryoconite of Renlongba glacier, respectively, on the Tibetan Plateau, PR China. The results of phylogenetic analysis based on 16S rRNA genes indicated that strains RB4R14 and RT5R15 belonged to the genus with the highest similarities to WPCB133 (98.78 %) and BJC16-A31 (97.64 %), respectively. The genomic DNA G+C contents of strains RB4R14 and RT5R15 were 42.8 and 43.1 mol%, respectively. The digital DNA-DNA hybridization values between strains RB4R14, RT5R15 and their close relatives were below 31.9 and 17.4 %, respectively. The average nucleotide identity values between the two novel strains and their close relatives were 79.5-82.0 and 77.9-79.3 % respectively, indicating the novelty of the two isolates at a species level. The two novel strains contained MK-7 as the major menaquinone, and summed feature 3 (comprising C 7 and/or C 6), iso-C and iso-C-3OH as the major fatty acids. The major polar lipid of the two novel strains were phosphatidylethanolamine. Based on phenotypic, chemotaxonomic and phylogenetic results, we propose two novel species, sp. nov. (RB4R14=CGMCC 1.11911=NBRC 114020) and sp. nov. (RT5R15=CGMCC 1.23117=NBRC 113930).