Abstract:

This experiment was conducted to understand the role of the σ^B factor in regulating the environmental stress of Listeria monocytogenes (LM). We constructed SigmaB gene deletion LM strain by using gene overlap extension PCR (SOE-PCR) and homologous recombination, and the environmental stress response of the strain on the different temperature, different pH condition and high osmotic pressure conditions were detected, and the transcription level of the genes that related with environment stress were tested by using qRT-PCR. The results showed that the environmental stress abilities of the SigmaB gene deletion mutant at the non-suitable conditions weakened and the transcriptional level of genes corresponding to environmental stress (rsbV, rsbW, hpt, clpP, ctsR) decreased significantly comparing with the standard strain. The results indicated that σ^B factor plays an important role in responding to environmental stress (temperature, pH and osmotic pressure) of LM. The study provides an important theoretical basis for further studies on its molecular mechanisms of environmental stress response and new target for drug action.