[Objective] Autolysis is a physiological accommodation of bacteria to lyse themselves under stress conditions.The aim of this study is to investigate comprehensively the autolysis of the lactic acid bacteria (LAB) strains stressed by various growth inhibitors.[Methods] The methods include the autolysis assay of of LAB strains with various origins,as well as the determination of autolysis profiles of Lactococcus lactis MG1363 under the conditions specified by different growth media and inhibitors' interference.[Results] The results showed that the autolysis ofL.lactis MG1363 could be induced in glucose strictly-limited medium through the action of ampicillin (Amp),and this phenomenon could only occur at the glucose exhausting point,indicating a growth phase-dependent pattern.And concomitantly,the expression of four predominant autolysins was significantly altered to a variable extent upon the addition of Amp.Furthermore,all the tested inhibitors negatively affected MG1363's autolysis under non-nutrient conditions,probably suggesting a mode of co-regulation between cell wall synthetic and hydrolytic enzymes.[Conclusion] Collectively,a significant discrepancy was proposed with respect to the autolysis of LAB strains administered with different inhibitors,and moreover,this peculiar phenomenon was strictly nutrition-and growth phase-dependent.%[目的]自溶是细菌在压力环境下通过自身裂解而获得的一种生理适应现象,研究的目的是全面探讨乳酸菌株在生长抑制剂条件下的自溶表型及机理.[方法]对多种来源的乳酸菌株的自溶能力进行检测,通过在不同生长条件和抑制剂压力条件下乳酸乳球菌MG1363的生长检测对其自溶表型进行分析.[结果]在葡萄糖严格受限的培养基中,氨苄青霉素的加入能够显著诱导MG1363的自溶,而且该自溶现象只发生在葡萄糖耗尽的时间点,展现出一种狭窄的生长时期依赖的特征.与此同时,因为氨苄青霉素的加入,4种主要的自溶酶的表达都发生了不同程度的显著改变.此外,所有受试的抑制剂都削弱了MG1363在非营养条件下的自溶,表明该菌株可能具有一种涉及细胞壁合成和降解酶的共同调控的模式.[结论]乳酸菌株在不同生长抑制剂条件下的自溶表型存在很大差异,且该自溶体现出营养条件和生长时期严格依赖的特征.
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