中文摘要：

目的分离和鉴定贮留在流式细胞仪流动室中的YL08菌株。方法从流式细胞仪流动室中活化、分离和纯化得到YL08分离株，接种于LB培养基和PBS缓冲液中，鉴定YL08分离株的形态和营养抗逆特性，通过16S rDNA的序列测定及构建系统发育进化树分析鉴定YL08分离株的种属。结果镜检显示YL08分离株呈短小杆状，革兰染色阴性；YL08分离株具有较强的低营养抗逆特性，在无营养的PBS缓冲液中可以生存6个月以上；序列比对及系统进化树分析证实YL08分离株为嗜麦芽寡养单胞菌（Stenortrophomonas maltophilia），同源性≥99％。结论从流式细胞仪流动室中分离得到1株具有低营养抗逆特性的嗜麦芽寡养单胞菌YL08株，为流式细胞仪的消毒维护及YL08分离株的低营养抗逆保护机制研究奠定基础。

英文摘要：

Objective To identify the bacterium strain,YL08,isolated from flow chamber of flow cytometry. Methods YL08 was first activated,isolated and purified from flow chamber of flow cytometry,and incubated in LB culture medium and PBS buffer. Then, YL08 was identified by the morphology, stress-tolerance characteristic and phylogenetic analyses of the 16S rDNA sequence. Results Microscopic examination showed that YL08 was a kind of Gram-negative short bacillus,and YL08 strain could survive more than 6 months in PBS buffer based on its strong rare nutrition resistance characteristic. Phylogenetic analyses indicated that YL08 belonged to Stenortrophomonas maltophilia（ Homology ≥ 99% ）. Conclusions A Stenortrophomonas maltophilia strain, YL08, which has strong stress-tolerance against rare nutrition condition, was isolated and identified from flow chamber of flow cytometry. The present study lays a foundation for the disinfection and maintenance of flow cytometry and the research on the stress-tolerance mechanism of YL08.