Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka, Japan.
Microb Pathog. 2010 Sep;49(3):90-4. doi: 10.1016/j.micpath.2010.05.002. Epub 2010 May 12.
As a stationary-phase signal, indole is secreted in large quantities by Escherichia coli on enriched media and has been shown to control several genes; however, its impact on acid resistance remains to be studied in detail. Real-time quantitative reverse transcription-polymerase chain reaction analysis revealed that indole increases the expression of the glutamine decarboxylase system that includes genes such as gadA, gadB, and gadC genes with no effect on the expression of other acid resistance systems such as arginine decarboxylase (adiA) and lysine decarboxylase (cadA, cadB, cadC, and ldcC). Indole also induces yhiE (gadE) that encodes the regulator required for expression of gadA, gadB, and gadC. These results suggest that indole enhances the survival of E. coli under acidic conditions by increasing the expression of acid resistance genes of the glutamine decarboxylase system, thus increasing its acid resistance.
吲哚作为一种定殖期信号，在富含营养的培养基上，大肠杆菌会大量分泌吲哚，并已被证实可以控制多个基因；然而，其对酸抗性的影响仍需详细研究。实时定量逆转录聚合酶链反应分析显示，吲哚增加了包括 gadA、gadB 和 gadC 基因在内的谷氨酰胺脱羧酶系统的表达，而对其他酸抗性系统（如精氨酸脱羧酶（adiA）和赖氨酸脱羧酶（cadA、cadB、cadC 和 ldcC）的表达没有影响。吲哚还诱导了编码gadA、gadB 和 gadC 表达所需调节剂的 yhiE（gadE）基因。这些结果表明，吲哚通过增加谷氨酰胺脱羧酶系统的酸抗性基因的表达，增强了大肠杆菌在酸性条件下的生存能力，从而提高了其酸抗性。
