生牛乳源假单胞菌蛋白水解特性及3种分型方法对其表型分布一致性的比较研究OA
Proteolytic properties of Pseudomonas isolated from raw milk and consistency of their phenotypic distribution with three typing methods:A comparative study
生牛乳在冷藏过程中易发生因以假单胞菌属(Pseudomonas)为代表的耐冷腐败菌的蛋白水解作用而发生品质劣变.为明确生牛乳源假单胞菌的蛋白水解表型特征,并评估不同分子分型方法对其腐败表型聚类一致性分析中的适用性,该研究以31株假单胞菌(包括26株来自上海生牛乳的分离株和5株标准菌株)为研究对象,并分别基于16S rRNA基因序列、核糖体分型指纹图谱及看家基因与蛋白酶基因组合的类多位点序列分型(multi-locus sequence typing-like typing,MLST-like)进行分子分型,系统比较各分型结果与蛋白水解表型分布的一致性.结果表明,67.7％的菌株在脱脂乳平板上产生水解圈,蛋白水解阳性菌株平均蛋白酶活力为0.56 △A·h-1·mL-1.在种水平鉴定上,核糖体分型较16S rRNA基因测序更具分辨力,48.4％的菌株被鉴定为荧光假单胞菌(Pseudomonas fluorescens).荧光假单胞菌组的蛋白水解能力显著高于非荧光假单胞菌组(P＜0.000 1).在与蛋白水解腐败表型分布一致性方面,16S rRNA基因序列分析与核糖体分型的聚类结果在蛋白水解表型分布上整体趋势相近;MLST-like分型与蛋白水解能力及蛋白水解致腐风险分级的对应关系最为清晰.该研究通过揭示生牛乳中假单胞菌蛋白水解表型的分布特征,评估3种分型方法在腐败风险识别中的适用性,为生牛乳中假单胞菌的腐败风险识别与分级防控提供参考.
Raw milk is prone to quality deterioration during cold storage due to the proteolytic activity of psychrotrophic spoilage bac-teria,particularly those belonging to the genus Pseudomonas.This study was conducted to clarify the proteolytic phenotypic characteristics of raw milk-derived Pseudomonas and to evaluate the applicability of different molecular typing methods in the consistency analysis of their spoilage phenotype clustering.A total of 31 Pseudomonas strains(including 26 isolates from raw milk in Shanghai and 5 type strains)were used as research subjects,and molecular typing was performed based on 16S rRNA gene sequences,ribotyping fingerprints,and a combi-nation of housekeeping genes and protease genes using multi-locus sequence typing-like typing(MLST-like),respectively,to systemati-cally compare the consistency of each typing result with the distribution of proteolytic phenotypes.The results showed that 67.7％of the strains produced clear zones on skim milk agar plates,and the average protease activity of the proteolytic-positive strains was 0.56 △A·h-1·mL-1.In species-level identification,ribotyping exhibited higher discriminatory power than 16S rRNA gene sequencing,with 48.4％of the strains identified as Pseudomonas fluorescens.The proteolytic capacity of the P.fluorescens group was significantly high-er than that of the non-P.fluorescens group(P＜0.000 1).Regarding consistency with the distribution of proteolytic spoilage phenotypes,the clustering results of 16S rRNA gene sequence analysis and ribotyping showed similar overall trends in the distribution of proteolytic phenotypes,while MLST-like typing exhibited the clearest correspondence with proteolytic capacity and the risk classification of proteolytic spoilage.This study revealed the distribution characteristics of proteolytic phenotypes of Pseudomonas in raw milk and evaluated the appli-cability of the three typing methods for identifying spoilage risk.These findings provided a reference for the identification and graded con-trol of spoilage risk posed by Pseudomonas in raw milk.
詹翠青;祁岩;游春苹
上海海洋大学食品学院,上海,201306||乳业生物技术国家重点实验室,农业农村部功能乳品加工重点实验室,上海乳业生物工程技术研究中心,光明乳业股份有限公司乳业研究院,上海,201103乳业生物技术国家重点实验室,农业农村部功能乳品加工重点实验室,上海乳业生物工程技术研究中心,光明乳业股份有限公司乳业研究院,上海,201103乳业生物技术国家重点实验室,农业农村部功能乳品加工重点实验室,上海乳业生物工程技术研究中心,光明乳业股份有限公司乳业研究院,上海,201103
生牛乳假单胞菌属蛋白酶16S rRNA基因序列分析核糖体分型类多位点序列分型
raw milkPseudomonasprotease16S rRNA gene sequence analysisribotypingmulti-locus sequence typing-like typing
《食品与发酵工业》 2026 (17)
61-73,13
市国资委企业创新发展和能级提升项目(2022013)
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