A mobile genetic element profoundly increases heat resistance of bacterial spores
A mobile genetic element profoundly increases heat resistance of bacterial spores
复制标题
DOI：
10.1038/ismej.2016.59
复制
发表时间：
2016-11-01
期刊：
影响因子：
11
通讯作者：
Wells-Bennik, Marjon H. J.
中科院分区：
文献类型：
--
作者：
Berendsen, Erwin M.;Boekhorst, Jos;Wells-Bennik, Marjon H. J.
细菌内生孢子是地球上最有弹性的生命形式之一，对极端环境和抗菌处理具有内在的抵抗力。它们的复原力是由独特的细胞结构所解释的，这种结构是由一个复杂的发育过程形成的，通常是在营养缺乏的情况下启动的。虽然来自不同细菌物种的孢子的大分子结构相似，但它们对环境侵害的抵抗力差异很大。目前还不知道哪些因素归因于孢子抗性赋予非常高水平的耐热性。在这里，我们提供了确凿的证据表明，在枯草芽孢杆菌，这是由于存在一个移动的遗传元件（Tn1546样）携带五个预测的操纵子，其中之一包含基因编码同源物的SpoVAC，SpoVAD和SpoVAEb和其他四个基因编码蛋白质与未知功能。这种操纵子被命名为spoVA（2mob），赋予孢子高水平的耐热性。a B中缺失spoVA（2 mob）。携带Tn1546的枯草杆菌菌株在将spoVA（2mob）转移到B中的同时产生热敏感孢子。subtilis 168产生高度耐热的孢子。基于芽孢杆菌科芽孢形成物种中不同spoVA操纵子的遗传保守性，我们提出了B中极端耐热芽孢出现的进化情景。枯草芽孢杆菌（B. subtilis）、B. licheniformis和B.解淀粉菌。这一发现为改进对能够产生高度耐热孢子的孢子形成细菌的检测和控制开辟了途径。
Bacterial endospores are among the most resilient forms of life on earth and are intrinsically resistant to extreme environments and antimicrobial treatments. Their resilience is explained by unique cellular structures formed by a complex developmental process often initiated in response to nutrient deprivation. Although the macromolecular structures of spores from different bacterial species are similar, their resistance to environmental insults differs widely. It is not known which of the factors attributed to spore resistance confer very high-level heat resistance. Here, we provide conclusive evidence that in Bacillus subtilis, this is due to the presence of a mobile genetic element (Tn1546-like) carrying five predicted operons, one of which contains genes that encode homologs of SpoVAC, SpoVAD and SpoVAEb and four other genes encoding proteins with unknown functions. This operon, named spoVA(2mob), confers high-level heat resistance to spores. Deletion of spoVA(2mob) in a B. subtilis strain carrying Tn1546 renders heat-sensitive spores while transfer of spoVA(2mob) into B. subtilis 168 yields highly heat-resistant spores. On the basis of the genetic conservation of different spoVA operons among spore-forming species of Bacillaceae, we propose an evolutionary scenario for the emergence of extremely heat-resistant spores in B. subtilis, B. licheniformis and B. amyloliquefaciens. This discovery opens up avenues for improved detection and control of spore-forming bacteria able to produce highly heat-resistant spores.