MALDI-TOF MS与16S rDNA方法对乳酸菌鉴定分析比较

Analysis and Comparison of The Identification of Lactic Acid Bacteria by MALDI-TOF MS and 16S rDNA Method

本研究通过将基质辅助激光解吸电离-飞行时间质谱(MALDI-TOF MS)法与16S rDNA序列分析法,对于乳酸菌鉴定的准确性以及微生物系统分类学相关分析结果进行比较,采用MALDI-TOF MS对本实验所保藏的3株乳酸菌标准菌株,及由乳制品中分离得到的12株乳酸菌进行蛋白质谱图收集,比对谱图特征峰对其进行鉴定及系统进行学分析;同时,进行16S rDNA提取并测序,得到分子生物化学水平鉴定,采用邻近连接法对16S rDNA序列进行系统进化树分析。结果表明,经MALDI-TOF MS与16S rDNA测序对试验所用的15株乳酸菌鉴定,乳杆菌属的2株微生物种水平鉴定结果存在偏差,其他13株鉴定结果一致;两种方法所得到的数据均可得出聚类热图及系统发育树,虽可确定为同一科水平,但不同属种水平微生物亲缘距离与位置有一定差异。MALDI-TOF MS法鉴定乳酸菌有着快速、准确的优势,但仍需要通过优化算法并扩大数据库以准确建立系统发育相关性。

In this study,the matrix-assisted laser desorption ionization-time-of-flight mass spectrometry(MALDI-TOF MS)method and the 16 S rDNA sequence analysis method were used to compare the accuracy of the identification of Lactic acid bacteria and the related analysis results of microbial system taxonomy.The 3 standard strains of lactic acid bacteria preserved in the experiment and the 12 strains of Lactic acid bacteria isolated from dairy products were collected for protein spectroscopy,and the characteristic peaks of the spectra were compared for identification and systematic scientific analysis;at the same time,16 S rDNA was extracted and analyzed.Sequencing,the identification of molecular biochemistry level was obtained,and the phylogenetic tree analysis of the 16 S rDNA sequence was performed using the neighbor ligation method.The results showed that the 15 strains of Lactic acid bacteria used in the experiment were identified by MALDI-TOF MS and16 S rDNA sequencing.There were deviations in the identification results of 2 strains of Lactobacillus at the level of the microbial species level,and the identification results of the other 13 strains were consistent;the data obtained by the two methods were both A clustering heat map and phylogenetic tree can be obtained.Although it can be determined to be at the same family level,there are certain differences in the relative distance and location of microorganisms at the level of different genera and species.The MALDI-TOF MS method has the advantages of rapid and accurate identification of Lactic acid bacteria,but it is still necessary to optimize the algorithm and expand the database to accurately establish the phylogenetic correlation.