摘要
【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、挥发性盐基氮(TVBN)含量、pH和感官评分,探讨nuoB对莓实假单胞菌生理特性和致腐作用的影响。【结果】体外培养条件下,nuoB并未影响莓实假单胞菌的生长能力、聚集性和swarming泳动性,但突变株的swimming泳动性和生物被膜形成能力在培养过程中显著下降。原位条件下,对冷鲜鸡肉致腐能力的评估发现两组样品菌落总数差异不显著,均达到了10 lg CFU·g^(-1);突变株组在冷鲜鸡肉储藏期间TVBN均显著低于野生株组,在第4天时才超过国家标准限量15 mg/100 g,培养末期的最大值约为野生株组的1/2;培养前2 d所有样品的pH均处于正常范围内,突变株组的pH从培养第5天开始显著低于野生株组;感官评价结果显示培养第4天时的两组样品均出现了黏液和异味,被判定为腐败,但突变株组样品稍弱于野生株组。【结论】nuoB的破坏没有影响莓实假单胞菌的生长能力,但抑制了菌株的泳动性、生物被膜形成和对冷鲜鸡肉的致腐能力。
【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 for
作者
王光宇
李晴
唐文倩
王虎虎
徐幸莲
邱伟芬
WANG GuangYu;LI Qing;TANG WenQian;WANG HuHu;XU XingLian;QIU WeiFen(College of Food Science and Engineering,Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and Safety of Jiangsu Province,Nanjing 210023;College of Food Science and Technology,Nanjing Agricultural University,Nanjing 210095)
出处
《中国农业科学》
CAS
CSCD
北大核心
2021年第8期1761-1771,共11页
Scientia Agricultura Sinica
基金
国家自然科学基金青年基金(31901759)
现代农业产业技术体系-肉鸡(CARS-41)。
关键词
莓实假单胞菌
基因
菌体特性
腐败
冷鲜鸡肉
Pseudomonas fragi
gene
bacterial property
spoilage
chilled chicken
