Objective To study the diversity and bioactivity of actinomycetes isolated from the south edge of the Taklamakan Desert, Xinjiang, China. Methods Using standard serial dilution plating method with ten different types of cultural media, 368 isolates were obtained. 166 strains were selected for 16S rRNAgene sequence analysis. Fermentation broths and mycelia of 96 strains were extracted respectively by ethyl acetate and acetone, the antifungal and antibacterial activity of the crude extracts were tested by disk diffusion method. Results 166 strains distributed in 24 different genera of 16 families. The dominant genera were Streptomyces and Nocardiopsis. The 16S rRNA sequence similarity between strain SC8A-24 and the nearest species Nocardioides salaries CL-Z59T in EzBioCloudrndatabase (DQ401092) was 96.41%, which indicated that strain SC8A-24 is a potential new species of Nocardioides. Antimicrobial test showed that 62 out of 96 strains exhibited positive results in at least one antifungal or antibacterial assay, and the total positive rate was 64.58%. Conclusion The study demonstrated the Taklamakan Desert is abundant with untapped actinomycetes that can produce a variety of bioactive substances, which could be a potential source for the discovery of new antibiotics.%目的 探测塔克拉玛干沙漠南麓放线菌多样性及抗菌活性,以期发现新药用微生物资源,为新抗生素发现奠定基础.方法 采用10种分离培养基,以稀释涂布法分离放线菌；采用16S rRNA基因序列分析放线菌多样性；放线菌液体发酵,发酵液乙酸乙酯萃取,菌丝体丙酮浸提;对获得的提取浓缩物,采用纸片扩散法进行抗菌活性筛选.结果 从17份土壤样品,共纯化到368株放线菌；其中166株经过16S rRNA序列分析的放线菌分布于16个科的24个属,链霉菌属和拟诺卡菌属为优势菌属；菌株SC8A-24的16Sr RNA基因序列与最近有效菌株Nocardioides salaries CL-Z59T(DQ401092)的相似率为96.41％,为潜在的新种；发酵96株放线菌,其中62株在至少一个抗菌活性筛选中显示为阳性,总阳性率为64.58％.结论 塔克拉玛干沙漠南麓土壤中存在较为丰富的药用放线菌资源,具有从中发现放线菌新物种及新结构抗生素的潜力.
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