Abstract: In this study, the traditional physiological and biochemical method, a VITEK automatic biochemical analyzer, the analytical profile index (API) biochemical identification system, real-time fluorescence quantitative polymerase chain reaction (real-time PCR) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) were used comparatively to identify the species of Pediococcus spp. in food. The results showed that the traditional physiological and biochemical method was the most accurate but time-consuming and labor-intensive; the VITEK automatic biochemical analyzer gave unstable results as the database states that Pediococcus acidilactici is negative for amygdalin reaction, whereas some strains actually test positive; the API biochemical identification system yielded accurate results at 24 h of culture, while deviations occurred when the culture period was extended to 48 h; real-time PCR was time-saving, accurate, and suitable for popularization; the MALDI-TOF MS method had the shortest operation time but high equipment requirements, making it difficult to popularize in primary-level institutions. In summary, the traditional physiological and biochemical method, real-time PCR, and MALDI-TOF MS can all serve as standard methods for the identification of Pediococcus spp. in food. The results of this study can provide a technical basis for the formulation of relevant national standards.

Key words: Pediococcus spp.; conventional physiological and biochemical method; VITEK biochemical identification system; analytical profile index biochemical identification method; real-time fluorescence quantitative polymerase chain reaction; matrix-assisted laser desorption ionization time-of-flight mass spectrometry

摘要： 采用传统生理生化法、VITEK生化鉴定法、分析谱型指数（analytical profile index，API）生化鉴定系统、实时荧光定量聚合酶链式反应（polymerase chain reaction，PCR）法、基质辅助激光解吸电离飞行时间质谱（matrix-assisted laser desorption ionization-time of flight mass spectrometry，MALDI-TOF MS）法对食品中片球菌属进行鉴定。结果表明，传统生理生化法结果最准确，但耗时长、工作量大；VITEK生化鉴定法因数据库规定乳酸片球菌苦杏仁苷反应为阴性，而实际部分菌株呈阳性，导致结果不稳定；API生化鉴定系统培养24 h结果准确，延长培养至48 h则出现偏差；实时荧光定量PCR法耗时短、结果准确，适合推广；MALDI-TOF MS法耗时最短，但设备要求高，难以在基层机构普及。综上，传统生理生化法、实时荧光定量PCR法和MALDI-TOF MS法均可作为食品中片球菌属鉴定的标准方法。本研究结果可为相关国家标准制定提供技术依据。

关键词: 片球菌属；传统生理生化法；VITEK生化鉴定法；分析谱型指数生化鉴定系统；实时荧光定量聚合酶链式反应法；基质辅助激光解吸电离飞行时间质谱