Increased Thermal and Osmotic Stress Resistance in Listeria monocytogenes 568 Grown in the Presence of Trehalose Due to Inactivation of the Phosphotrehalase-Encoding Gene treA
Increased Thermal and Osmotic Stress Resistance in Listeria monocytogenes 568 Grown in the Presence of Trehalose Due to Inactivation of the Phosphotrehalase-Encoding Gene treA
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DOI：
10.1128/aem.00757-11
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发表时间：
2011-10-01
影响因子：
4.4
通讯作者：
Hansen, Lisbeth Truelstrup
中科院分区：
文献类型：
--
作者：
Ells, Timothy C.;Hansen, Lisbeth Truelstrup
食源性病原体单核细胞增生李斯特菌对食品加工者和消费者都是一个问题，因为该生物体对恶劣的环境条件和为防止有害细菌的存活和/或生长而实施的有害屏障具有抗性。其中一个机制，通过该介导的存活是通过积累相容的溶质，如脯氨酸，甜菜碱和肉毒碱。在其他细菌中，包括大肠杆菌，另一种相容性溶质海藻糖的合成和积累有助于应激细胞的存活。本研究的目的是研究海藻糖在L.在单核细胞增多症中，糖被认为是通过特异性磷酸烯醇丙酮酸磷酸转移酶系统和磷酸化为海藻糖-6-磷酸（T6 P）跨细胞质膜转移。后者随后被α，α-（1，1）磷酸海藻糖酶（TreA基因的推定产物）分解为葡萄糖和葡萄糖-6-磷酸。在这里，我们报告了一个等基因的treA突变的L。单核细胞增多症568（568：Delta TreA），其相对于野生型菌株显示出对多种应激源（包括热、高渗透压和干燥）的耐受性增加。这是第一次研究L. lmo 1254（treA）在单核细胞增生性李斯特氏菌中表达。单核细胞增多症568确实编码水解T6 P所需的磷酸海藻糖酶。treA基因的破坏导致T6 P的积累，其随后在胞质溶胶中去磷酸化为海藻糖，从而有助于在treA突变体中观察到的胁迫抗性。这项研究强调了相容性溶质对微生物在不利环境中生存的重要性。
The food-borne pathogen Listeria monocytogenes is a problem for food processors and consumers alike, as the organism is resistant to harsh environmental conditions and inimical barriers implemented to prevent the survival and/or growth of harmful bacteria. One mechanism by which listeriae mediate survival is through the accumulation of compatible solutes, such as proline, betaine and carnitine. In other bacteria, including Escherichia coli, the synthesis and accumulation of another compatible solute, trehalose, are known to aid in the survival of stressed cells. The objective of this research was to investigate trehalose metabolism in L. monocytogenes, where the sugar is thought to be transferred across the cytoplasmic membrane via a specific phosphoenolpyruvate phosphotransferase system and phosphorylation to trehalose-6-phosphate (T6P). The latter is subsequently broken down into glucose and glucose-6-phosphate by alpha,alpha-(1,1) phosphotrehalase, the putative product of the treA gene. Here we report on an isogenic treA mutant of L. monocytogenes 568 (568:Delta TreA) which, relative to the wild-type strain, displays increased tolerances to multiple stressors, including heat, high osmolarity, and desiccation. This is the first study to examine the putative trehalose operon in L. monocytogenes, and we demonstrate that lmo1254 (treA) in L. monocytogenes 568 indeed encodes a phosphotrehalase required for the hydrolysis of T6P. Disruption of the treA gene results in the accumulation of T6P which is subsequently dephosphorylated to trehalose in the cytosol, thereby contributing to the stress hardiness observed in the treA mutant. This study highlights the importance of compatible solutes for microbial survival in adverse environments.