Global analysis of Escherichia coli gene expression during the acetate-induced acid tolerance response
Global analysis of Escherichia coli gene expression during the acetate-induced acid tolerance response
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DOI：
10.1128/jb.183.7.2178-2186.2001
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发表时间：
2001-04-01
影响因子：
3.2
通讯作者：
Siegele, DA
中科院分区：
文献类型：
--
作者：
Arnold, CN;McElhanon, J;Siegele, DA
大肠杆菌在低pH下存活的能力受到环境因素的强烈影响，例如生长培养基和生长期的组成。在中性或接近中性的pH下暴露于短链脂肪酸，如乙酸盐、丙酸盐和丁酸盐，也显示出增加酸存活。大肠杆菌和鼠伤寒沙门氏菌。探讨乙酸诱导E. coliO157：H7中，用基因芯片鉴定了乙酸盐诱导表达改变的基因。60个基因的表达减少了至少两倍，其中48个编码转录翻译机制的组件。26个基因的表达增加了两倍或更大的治疗与乙酸。这包括已知其产物对于在低pH下的存活是重要的六个基因，这些基因中的五个以及其他六个乙酸诱导的基因是大肠杆菌RpoS调节子的成员，RpoS是已知由在非致死性低pH下生长或进入稳定期诱导的酸耐受性所需的应激σ因子。通过转座子插入突变破坏rpoS基因也阻止了乙酸诱导的耐酸性。然而，诱导RpoS表达似乎不足以激活酸耐受反应。用NaCl或乙酸钠（pH 7.0）处理增加了rpoS：：lacZ融合蛋白的表达，但仅用乙酸盐处理增加了酸存活。
The ability of Escherichia coli to survive at low pH is strongly affected by environmental factors, such as composition of the growth medium and growth phase. Exposure to short chain fatty acids, such as acetate, proprionate, and butyrate, at neutral or nearly neutral pH has also been shown to increase acid survival off. coli and Salmonella enterica serovar Typhimurium. To investigate the basis for acetate induced acid tolerance in E. coli O157:H7, genes whose expression was altered by exposure to acetate were identified using gene arrays. The expression of 60 genes was reduced by at least twofold; of these, 48 encode components of the transcription translation machinery. Expression of 26 genes increased twofold or greater following treatment with acetate. This included six genes whose products are known to be important for survival at low pH, Five of these genes, as well as six other acetate-induced genes, are members of the E, coli RpoS regulon, RpoS, the stress sigma factor, is known to be required for acid tolerance induced by growth at nonlethal low pH or by entry into stationary phase. Disruption of the rpoS gene by a transposon insertion mutation also prevented acetate-induced acid tolerance. However, induction of RpoS expression did not appear to be sufficient to activate the acid tolerance response. Treatment with either NaCl or sodium acetate (pH 7.0) increased expression of an rpoS::lacZ fusion protein, but only treatment with acetate increased acid survival.