Kim Eiseul, Yang Seung-Min, Kim Hyun-Jae, Kim Hae-Yeong
Department of Food Science and Biotechnology, Institute of Life Sciences & Resources, Kyung Hee University, Yongin 17104, Korea.
Foods. 2022 Apr 5;11(7):1046. doi: 10.3390/foods11071046.
Unlike strains, some strains are considered potential probiotic strains as they lack particular virulence and antibiotic resistance genes. However, these closely related species are difficult to distinguish via conventional taxonomic methods. Here, for the first time, we used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with BioTyper and in-house databases to distinguish between . and . . A total of 58 reference and isolated strains (89.2%) were correctly identified at the species level using MALDI-TOF MS with in-house databases. However, seven strains (10.8%) were not accurately differentiated as a single colony was identified as a different species with a similar score value. Specific mass peaks were identified by analyzing reference strains, and mass peaks at 10,122 ± 2 /, 3650 ± 1 /, and 7306 ± 1 / were unique to . and . reference strains, respectively. Mass peaks verified reproducibility in 60 isolates and showed 100% specificity, whereas 16S rRNA sequencing identified two different candidates for some isolates (. and . ). Our specific mass peak method helped to differentiate two species, with high accuracy and high throughput, and provided a viable alternative to 16S rRNA sequencing.
与其他菌株不同，一些菌株被认为是潜在的益生菌菌株，因为它们缺乏特定的毒力和抗生素抗性基因。然而，这些密切相关的物种很难通过传统的分类方法区分开来。在这里，我们首次使用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）结合BioTyper和内部数据库来区分[具体物种1]和[具体物种2]。使用带有内部数据库的MALDI-TOF MS，在物种水平上总共正确鉴定了58株参考菌株和分离菌株（89.2%）。然而，有7株菌株（10.8%）没有被准确区分，因为一个单菌落被鉴定为具有相似分数值的不同物种。通过分析参考菌株确定了特异性质量峰，10122±2 m/z、3650±1 m/z和7306±1 m/z的质量峰分别是[具体物种1]和[具体物种2]参考菌株所特有的。质量峰在60株分离物中验证了可重复性，并显示出100%的特异性，而16S rRNA测序对一些分离物鉴定出了两个不同的候选物种（[具体物种1]和[具体物种2]）。我们的特异性质量峰方法有助于以高精度和高通量区分这两个物种，并为16S rRNA测序提供了一种可行的替代方法。
