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Two novel strain pairs (HM61 T /HM23 and S-34 T /S-58) were isolated from soil and the faeces of Tibetan antelope ( Pantholops hodgsonii ) collected at the Qinghai-Tibet Plateau of PR China. All four new isolates were aerobic, non-motile, Gram-stain-positive, catalase-positive, oxidase-negative, and short rod-shaped bacteria. The results of phylogenetic analysis based on the full-length 16S rRNA genes and 283 core genomic genes indicated that the four strains were separated into two independent branches belonging to the genus Nocardioides . Strains HM61 T and HM23 were most closely related to Nocardioides pelophilus THG T63 T (98.58 and 98.65 % 16S rRNA gene sequence similarity). Strains S-34 T and S-58 were most closely related to Nocardioides okcheonensis MMS20-HV4-12 T (98.89 and 98.89 % 16S rRNA gene sequence similarity). The G+C contents of the genomic DNA of strains HM61 T and S-34 T were 70.6 and 72.5 mol%, respectively. Strains HM61 T , S-34 T and the type strains of closely related species in the analysis had average nucleotide identity values of 75.4-90.5 % as well as digital DNA-DNA hybridization values between 20.1 and 40.8 %, which clearly indicated that the four isolates represent two novel species within the genus Nocardioides . The chemotaxonomic characteristics of strains HM61 T and S-34 T were consistent with the genus Nocardioides . The major fatty acids of all four strains were iso -C 16 : 0 , C 17 : 1  ω 8 c or C 18 : 1  ω 9 c . For strains HM61 T and S-34 T , MK-8(H 4 ) was the predominant respiratory quinone, ll-2,6-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan, and the polar lipids profiles were composed of diphosphatidylglycerol and phosphatidylglycerol. Based on phylogenetic, phenotypic, and chemotaxonomic data, we propose that strains HM61 T and S-34 T represent two novel species of the genus Nocardioides , respectively, with the names Nocardioides bizhenqiangii sp. nov. and Nocardioides renjunii sp. nov. The type strains are HM61 T (=GDMCC 4.343 T =JCM 36399 T ) and S-34 T (=CGMCC 4.7664 T =JCM 33792 T ).

The essential oil of Tibetan medicine Dracocephalum heterophyllum Benth was obtained by hydrodistillation with a 0.7% (v/w) yield. The chemical composition of the essential oil was analyzed by gas chromatography-mass spectral (GC-MS). Eighty-three compounds, constituting about 89.83% of the total oil, were identified. The main compound in the oil were Cineole (14.89%), trans-nerolido (7.10%), 1-m-ethyl-2-(1-methylethyl)-benzene (4.42%), Germacrene-D (4.84%), Decahydro-1,1,4,7-tetramethyl-4aH-cycloprop[e]azulen-4a-ol (4.94%), p-menth-1-en-4-ol,acetate (4.34%), 4-methyl-1-(1-methylethyl)-3-cyclohexen-1-ol (4.10%). The antimicrobial activity of the oil was evaluated against nine bacterial, one yeast, and three fungi. The antimicrobial test result showed that the essential oil strongly inhibited the growth of test microorganisms studied. The maximal inhibition zones and MIC values for bacterial, yeast and fungi strain were in the range of 18-25 mm and 0.039-0.156 mg mL(-1); *20 mm, and 0.156 mg mL(-1); 8-24 mm and 0.313-2.5 mg mL(-1); respectively. The antioxidant activity of the oil was determined by the malonyldialdehyde (MDA) test, measuring the MDA concentration in mouse liver cell microsomal after induced lipid peroxidation using FeSO(4) and ascorbic acid, The inhibition of lipid peroxidation was 59.3% with a concentration of 0.5 mg mL(-1). Result presented here may suggest that the essential oil of D. heterophyllum posses antimicrobial and antioxidant properties, and therefore, they can be one of new medicinal resources for antimicrobial agent and/or used as a natural preservative ingredient in food and cosmetics and pharmaceuticals industry.