Analysis of the role of bacterial endospore cortex structure in resistance properties and demonstration of its conservation amongst species
Analysis of the role of bacterial endospore cortex structure in resistance properties and demonstration of its conservation amongst species
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DOI：
10.1046/j.1365-2672.2001.01394.x
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发表时间：
2001-08-01
影响因子：
4
通讯作者：
Foster, SJ
中科院分区：
文献类型：
--
作者：
Atrih, A;Foster, SJ
目的：本工作的目的是比较一系列物种的孢子皮层的化学结构，并确定皮层结构与孢子抗性特性之间的相关性。方法和结果：使用反相 HPLC 进行胞肽分析，检查枯草芽孢杆菌、巨大芽孢杆菌、蜡样芽孢杆菌和肉毒梭菌的皮层精细化学结构。这些物种的肽聚糖之间存在保守的基本结构，唯一的区别是氨基糖的脱N-乙酰化水平。为了确定皮层结构的改变是否与耐热特性相关，对不同条件下制备的枯草芽孢杆菌孢子的肽聚糖结构和特性进行了比较。来自营养肉汤 (NB) 中制备的孢子的肽聚糖显示，单一 L-丙氨酸取代的胞壁酸仅减少了 13.9%，而 CCY 生长的孢子中的肽聚糖为 20.6%。 NB 制备的孢子也不稳定，其耐热性（60 分钟，85 摄氏度）比 CCY 生长的孢子低 161 倍，Mn2+ 含量低 43 倍。向 NB 中添加 MnCl2 会导致肽聚糖特征与 CCY 生长的孢子相似，耐热性提高七倍（60 分钟，85 摄氏度），并且 Mn2+ 含量增加 86 倍。向 NB 中添加 CCY 盐导致所有参数与 CCY 生长的孢子水平相当。结论：已表明肽聚糖结构在四种孢子形成细菌中是保守的。此外，孢子耐热性是多因素的，不能用任何单一参数来解释。研究的意义和影响：不同物种产生的内生孢子很可能具有共同的耐热机制。然而，其耐药性的分子基础仍然难以捉摸。
Aims: The aim of this work was to compare the chemical structure of the spore cortex of a range of species, and to determine any correlation between cortex structure and spore resistance properties.Methods and Results: The fine chemical structure of the cortex of Bacillus subtilis, Bacillus megaterium, Bacillus cereus and Clostridium botulinum was examined by muropeptide analysis using reverse phase HPLC. There is a conserved basic structure between peptidoglycan of these species, with the only difference being the level of de-N-acetylation of an amino sugar. In order to determine if an alteration in cortex structure correlates with heat resistance properties, the peptidoglycan structure and properties of B. subtilis spores prepared under different conditions were compared. Peptidoglycan from spores prepared in Nutrient Broth (NB) showed reduction in single L-alanine substituted muramic acid to only 13.9% compared with 20.6% in CCY-grown spores. NB-prepared spores are also unstable, with 161-fold less heat resistance (60 min, 85 degreesC) and 43 times less Mn2+ content than CCY-grown spores. Addition of MnCl2 to NB led to a peptidoglycan profile similar to CCY-grown spores, sevenfold more heat resistance (60 min, 85 degreesC) and an 86-fold increase in Mn2+ content. Addition of CCY salts to NB led all parameters to be comparable with CCY-grown spore levels.Conclusions: It has been shown that peptidoglycan structure is conserved in four spore-forming bacteria. Also, spore heat resistance is multifactorial and cannot be accounted for by any single parameter.Significance and Impact of the Study: Endospores made by diverse species most likely have common mechanisms of heat resistance. However, the molecular basis for their resistance remains elusive.