nuoB对莓实假单胞菌生理特性及在冷鲜鸡肉中致腐能力的影响

[目的]研究nuoB对莓实假单胞菌菌体特性及其对冷鲜鸡肉致腐能力的影响,为揭示nuoB介导的冷鲜鸡肉腐败机制,开发新型保鲜技术提供理论依据.[方法]通过构建nuoB插入失活突变株,对比野生株和突变株在体外培养条件下的生长曲线、聚集性、泳动性和生物被膜形成能力;以及原位培养条件对冷鲜鸡肉的致腐特征,包括菌落总数、挥发性盐...

Effects of nuoB on Physiological Properties of Pseudomonas fragi and Its Spoilage Potential in Chilled Chicken

【Objective】The effects of nuoB on the properties of Pseudomonas fragi and its spoilage activity on chilled chicken were studied in this work, which could provide a theoretical basis for revealing mechanism of nuoB-mediated chilled chicken spoilage and developing new preservation technologies. 【Method】The nuoB mutant was constructed by inserting a resistance cartridge to analyze the differences of the growth curve, aggregation, motility, and biofilm formation ability between the wild type and the mutant in vitro. The effects on the spoilage characteristics of chilled chicken were studied in situ, including the total viable count, TVBN, pH, and sensory evaluation. This study investigated the influence of nuoB on the physiological properties and spoilage potential of P. fragi. 【Result】The results showed that nuoB did not affect the growth condition, aggregation, and swarming motility of P. fragi. However, the swimming motility and biofilm formation of the mutant were significantly decreased during the incubation period. The in situ assessment of the spoilage ability on chilled chicken showed that there was no significant difference in the total viable count between two groups, which both reached to 10 lg CFU·g ^-1. The TVBN in the mutant group was significantly lower than that in the wild type group during the whole storage period and exceeded the national standard limit of 15 mg/100 g on the 4th day. The maximum value of TVBN in the mutant group at the end of storage was about half of that in the wild type group. The pH values of both samples were within the normal levels in the first 2 days, while the mutant group was significantly lower than that in the wild type group after the 5th day. Sensory evaluation results showed that slime and odor occurred in both groups on day 4, which could be considered as spoilage, but the spoilage extent of mutant group was slightly weaker than the wild type group. 【Conclusion】The destruction of nuoB did not affect the growth ability of P. fragi, but inhibited its swimming motility, biofilm formation, and spoilage potential in chilled chicken.