奶粉中一株阪崎肠杆菌的鉴定及其挥发性产物分析

Identification of a strain of Enterobacter sakazakii from milk powder and analysis of its volatile compounds

中文关键词:  阪崎肠杆菌  鉴定  挥发性产物  顶空气相色谱-质谱联用法

英文关键词:Enterobacter sakazakii  identification  volatile compounds  headspace gas chromatography-mass spectrometry

中文摘要:

      目的 鉴定奶粉中一株阪崎肠杆菌分离菌株F2-1, 采用顶空气相色谱-质谱联用法(headspace gas chromatography-mass spectrometry, HS-GC-MS)分析分离菌株F2-1在液态培养中产生的挥发性代谢产物。 方法 应用VITEK 2 Compact全自动微生物鉴定系统分析分离菌株的生理生化特征; 利用环介导等温扩增技术(loop-mediated isothermal amplification, LAMP)特异性扩增检测分离菌株的16S rDNA, 通过HS-GC-MS分析分离菌株F2-1代谢的挥发性产物。结果 分离菌株F2-1为革兰氏阴性菌, 生理生化特征与阪崎肠杆菌(Enterobacter sakazakii, ES)的相似性为99%, LAMP检测进一步确认为阪崎肠杆菌, 分离菌株F2-1在营养肉汤中代谢的挥发性产物主要有异戊醛、乙醇、异戊醇、3-羟基-2-丁酮、乙酸、正十五烷、正十六烷、正十七烷、1-癸醇。结论 奶粉中分离菌株F2-1鉴定为阪崎肠杆菌, 该菌产生的挥发性产物为阪崎肠杆菌的快速鉴定提供参考。

英文摘要:

      Objective To identify an isolated strain of Enterobacter sakazakii F2-1 in milk powder, and analyze the volatile metabolites produced by isolate F2-1 in liquid culture by headspace gas chromatography-mass spectrometry (HS-GC-MS). Methods The physiological and biochemical characteristics were elucidated by using VITEK 2 compact automated microbiology system. The 16S rDNA of isolated strains was amplified by loop-mediated isothermal amplification (LAMP). The volatile compounds (VCs) from F2-1 cultured with liquid-state nutrient broth were analyzed by headspace gas chromatography-mass spectrometry (HS-GC-MS). Results The isolated strain F2-1 was a Gram-negative bacterium, and its physiological and biochemical characteristics were 99% similar to Enterobacter sakazakii (ES). It was confirmed as Enterobacter sakazakii by LAMP test. The volatile products metabolized by strain F2-1 in nutrient broth were isovaleraldehyde, ethanol, isoamyl alcohol, 3-hydroxy-2-butanone, acetic acid, n-pentane, n-cetane, n-heptadecane, 1-decanol. Conclusion Bacterial strain F2-1 isolated from the milk power Is identified as Enterobacter sakazakii. The VCs produced by F2-1 will provide basis for the rapid identification of Enterobacter sakazakii.