交互保护对干酪乳杆菌ATCC 393^(TM)存活的影响  

Influence of cross-protection on the survival of Lactobacillus casei ATCC 393

作　　者：薛峰[1,2] 张娟[1,2] 堵国成[1,2] 陈坚[2,3] 

机构地区：[1]江南大学工业生物技术教育部重点实验室,无锡214122 [2]江南大学生物工程学院,无锡214122 [3]江南大学食品科学与技术国家重点实验室,无锡214122

出　　处：《微生物学报》2010年第4期478-484,共7页Acta Microbiologica Sinica

基　　金：国家“973项目”(2007CB714306);国家自然科学基金重点项目(20836003);国家自然科学基金(30800008,30900013)~~

摘　　要：【目的】以干酪乳杆菌典型株ATCC 393TM(Lactobacillus casei ATCC 393TM)为实验菌株,研究其在多重胁迫环境下的交互保护应答机制。【方法】比较不同亚适应条件(热、H2O2、酸、胆盐)处理后菌体细胞在热致死条件(>60℃)及氧致死条件H2O2(>5mmol/L)下的存活率变化,并集中考察了最佳亚适应条件-酸适应的不同处理方式对细胞交互保护存活率、胞内pH以及脂肪酸含量的影响。【结果】交互保护对干酪乳杆菌ATCC393生理活性的影响因亚适应及致死条件而异:酸胁迫预适应能够显著提高细胞的交互胁迫抗性,其中,盐酸预适应的交互保护效果优于乳酸,其预适应引发的生理应答效应使细胞在应对热致死和氧致死胁迫时存活率分别提高了305倍和173倍;进一步的研究表明,酸预适应提高细胞存活率的作用机制可能与其能够显著改善胁迫环境下的胞内pH和细胞膜脂肪酸不饱和度相关。【结论】盐酸预适应对干酪乳杆菌典型株ATCC393的交互保护作用最为显著,并能够维持胁迫条件下细胞生理状态的相对稳定,本研究将有助于进一步解析干酪乳杆菌在对抗不同胁迫环境的过程中生理应答机制间的相互作用关系。Objective In this study,we investigated the cross-protection of Lactobacillus casei ATCC ○R 393TM under multi-stress conditions.MethodsCells pre-adapted to mild conditions（heat,H2O2,acid or bile salts） were then treated at lethal temperature（ 60℃ ） or hydrogen peroxide stress（ 5 mmol /L）.Furthermore,the changes of survival rate, intracellular pH and membrane fatty acid under lethal conditions with or without acid adaption were compared.Results The cross-protection in Lactobacillus casei ATCC 393TM were affected by different stress conditions.Acid pre-adaption, especially hydrochloride treatment,would increase the resistance of cells to lethal heat and peroxide stresses significantly, with the survival rate of 305-fold and 173-fold,respectively.Further study suggested that the effect of acid pre-adaption might be related to the regulation on intracellular pH and the saturation of cell membrane.ConclusionHydrochloride adaption was the best inducer for the cross-protection of Lactobacillus casei ATCC 393TM to maintain relatively stable physiological status of cells.The results supplied a novel way to investigate the relationship between different protective mechanisms in L.casei under different kinds of stresses.

关 键 词：干酪乳杆菌 交互保护 胁迫抗性 胞内pH 膜脂肪酸 

分 类 号：Q935[生物学—微生物学]