Identifying the Lactobacillus plantarum group using conventional taxonomic methods such as biochemical analysis and 16S rRNA gene sequencing is inaccurate, expensive, and time-consuming. In this study, for the first time, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to identify the L. plantarum group and develop a classification method for species level differentiation with specific peaks based on mass spectra. Furthermore, from the mass spectra of 131 isolates aligned with the biotyper database, 131 isolates (100%) were correctly identified at the species level with a mean score of 2.316. However, commercial databases could not accurately differentiate some isolates of L. plantarum group species because the same colony was identified as different species with similar score values. Moreover, these two species showed a similar mass pattern in the main spectrum profiles-dendrogram and Principal component analysis clustering generated by the mass peak of the reference strains and isolates. Specific peaks to each species were investigated from the analyzed mass peak, and they clearly showed that three species could be differentiated. These peaks were verified by re-identifying 131 isolates, and it demonstrated 100% specificity and accuracy. Also, using a specific peak, isolates that were undifferentiated from the biotyper database were clearly identified as one species, similar to species-specific polymerase chain reaction. Our data demonstrate that the specific peaks accurately differentiate the L. plantarum group and enable high-resolution identification at the species level; this methodology can be used to rapidly and easily identify them and determine their nomenclature.

使用生化分析和 16S rRNA 基因测序等传统分类方法来鉴定植物乳杆菌群是不准确、昂贵且耗时的。本研究首次利用基质辅助激光解吸/电离飞行时间质谱技术对植物乳杆菌类群进行鉴定，并建立了一种基于质谱的特定峰物种水平区分的分类方法。此外，根据与生物型数据库对齐的 131 个分离株的质谱，131 个分离株 (100%) 在物种水平上被正确识别，平均得分为 2.316。然而，商业数据库无法准确区分植物乳杆菌组物种的某些分离株，因为同一菌落被鉴定为具有相似分值的不同物种。此外，这两个物种在由参考菌株和分离株的质量峰生成的主谱图树状图和主成分分析聚类中显示出相似的质量模式。从分析的质量峰中研究了每个物种的特定峰，它们清楚地表明可以区分三个物种。这些峰通过重新鉴定 131 个分离株进行了验证，并表现出 100% 的特异性和准确性。此外，使用特定的峰，与生物型数据库中未分化的分离株被清楚地识别为一个物种，类似于物种特异性聚合酶链反应。我们的数据表明，特定的峰可以准确地区分植物乳杆菌组，并能够在物种水平上进行高分辨率识别；这种方法可用于快速、轻松地识别它们并确定它们的命名法。