利用MALDI-TOF MS鉴定芽苗菜中解鸟氨酸拉乌尔菌和肺炎克雷伯菌的研究

应用基质解析电离飞行时间质谱(MALDI-TOF MS)方法对芽苗菜中检出率较高的2种微生物进行鉴定,结果为解鸟氨酸拉乌尔菌(33.3%)和肺炎克雷伯菌(43.5%)。应用SARAMIS Premium软件对这2种微生物的蛋白质图谱进行分析,获得解鸟氨酸拉乌尔菌特征标识峰16组,肺炎克雷伯菌特征标识峰10组;对分离微生物进行全标识峰和加权特征峰相关性分析,结果表明特征峰的加权会影响微生物鉴定结果间的相关关系,增强微生物的辨识度;对两种微生物进行多方面比较,发现两种微生物生化特性比较接近,但16Sr DNA分辨率较高,质谱相关分析虽有相交但可辨识。实验结果表明MALDI-TOF MS具有检测芽苗菜中微生物的能力并在其特征分析及溯源研究上具有一定的优势,MALDI-TOF MS为开放平台,对农产品微生物蛋白质特征图谱的收集与优化可提高其鉴定准确性。

Research on Identification of Raoultella ornithinolytica and Klebsiella pneumoniae in Sprouts by MALDI-TOF MS

Two kinds of microorganisms with high detection rate in sprouts were identified by MALDI-TOF MS method as Raoultella ornithinolytica(33.3%) and Klebsiella pneumoniae(43.5%),respectively.The protein spectrums for the two microorganisms were analyzed by SARAMIS Premium,and 16 groups of characteristic peaks for R.ornithinolytica and 10 groups of characteristic peaks for K.pneumonia were identified.All peaks and weighted characteristic peaks were used for correlation analysis.The weighting for characteristic peaks could effect the correlation between different microorganisms and strengthen their resolutions.Through comparion by several methods,the two kinds of microorganisms are relatively similar in biochemical reactions.However,the 16SrDNA could isolate them,and their MS correlation trees were recognizable even though they intersected each other.The experimental results show that MALDI-TOF MS is capable of detecting the microorganisms in sprouts,and has certain advantages in their feature analysis and traceability research.MALDI-TOF MS/SARAMIS,as an open platform,could be expanded its applicable scope and improved its identified accuracy by the collection and optimization of microbial characteristics spectrums.