Milecka Dorota, Samluk Anna, Wasiak Katarzyna, Krawczyk-Balska Agata
Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland.
Arch Microbiol. 2015 Mar;197(2):347-51. doi: 10.1007/s00203-014-1053-4. Epub 2014 Oct 29.
The expression of ten genes of Listeria monocytogenes previously identified as penicillin G-inducible was transcriptionally analyzed in the presence of 0.5 M KCl, pH 5.0 and 42 °C. This study revealed that all the genes are upregulated by osmotic stress, seven by acid stress and four by temperature stress conditions. The contribution of a gene encoding a ferritin-like protein (fri), a two-component phosphate-response regulator (phoP) and an AraC/XylS family transcription regulator (axyR) to temperature, acid and osmotic stress tolerance was further examined by analysis of nonpolar deletion mutants. This revealed that a lack of PhoP or AxyR does not affect the ability to grow under the tested stress conditions. However, the Δ fri strain showed slightly delayed growth under osmotic and clearly impaired growth under acid stress conditions, indicating an important role of the ferritin-like protein in acid stress tolerance.
在0.5M KCl、pH 5.0和42°C条件下，对先前鉴定为青霉素G诱导型的单核细胞增生李斯特菌的十个基因的表达进行了转录分析。该研究表明，所有基因均在渗透胁迫下上调，七个基因在酸胁迫下上调，四个基因在温度胁迫条件下上调。通过分析非极性缺失突变体，进一步研究了编码铁蛋白样蛋白（fri）、双组分磷酸盐反应调节因子（phoP）和AraC/XylS家族转录调节因子（axyR）的基因对温度、酸和渗透胁迫耐受性的贡献。结果表明，缺乏PhoP或AxyR并不影响在测试胁迫条件下的生长能力。然而，Δfri菌株在渗透胁迫下生长略有延迟，在酸胁迫条件下生长明显受损，表明铁蛋白样蛋白在酸胁迫耐受性中起重要作用。
