Haddaji Najla, Mahdhi Abdel Karim, Krifi Boubaker, Ismail Manel Ben, Bakhrouf Amina
Laboratory of Analysis, Treatment and Valorization of the Pollutants of the Environment and Products, Faculty of Pharmacy, University of Monastir, Monastir Avicenne Street, Monastir 5000, Tunisia
Laboratory of Analysis, Treatment and Valorization of the Pollutants of the Environment and Products, Faculty of Pharmacy, University of Monastir, Monastir Avicenne Street, Monastir 5000, Tunisia.
FEMS Microbiol Lett. 2015 May;362(9). doi: 10.1093/femsle/fnv047. Epub 2015 Mar 30.
We undertake this study in the aim to give new insight about the change in cellular physiological state under heat shock treatment and probiotic strain screening procedure. Different cell properties have been studied like adhesive ability to biotic and abiotic surfaces, the cell surface hydrophobicity and the fatty acids profiles. Compared to the normal cells, the heated cells increased their adhesive ability to biotic surface. However, the adhesion to abiotic surface was decreased. The cell surface hydrophobicity of the heated strains showed a significant decrease (P < 0.05). Our data revealed that high temperature change the fatty acids profiles of the treated cells, especially the proportions of unsaturated and saturated fatty acid. In fact, the ratio of saturated to unsaturated fatty acids of the heated Lactobacillus casei cells was significantly higher than that of the control cells (P < 0.05). The present finding could firstly add new insight about the response of probiotic to stressful conditions, such us the important role of cell membrane, considered as the first main structure to be damaged by physicochemical stress, in stress resistance because of their composition that can change in adaptation to harsh conditions. Secondly, there is no relationship between changes in membrane composition and fluidity induced by heat shock treatment and adhesion to biotic and abiotic surface.
我们开展这项研究的目的是深入了解热休克处理和益生菌菌株筛选过程中细胞生理状态的变化。我们研究了不同的细胞特性，如对生物和非生物表面的黏附能力、细胞表面疏水性以及脂肪酸谱。与正常细胞相比，受热细胞对生物表面的黏附能力增强。然而，对非生物表面的黏附能力下降。受热菌株的细胞表面疏水性显著降低（P < 0.05）。我们的数据表明，高温会改变处理后细胞的脂肪酸谱，尤其是不饱和脂肪酸和饱和脂肪酸的比例。事实上，受热的干酪乳杆菌细胞的饱和脂肪酸与不饱和脂肪酸的比例显著高于对照细胞（P < 0.05）。本研究结果首先能为益生菌对压力条件的反应提供新的见解，例如细胞膜作为物理化学应激下首个主要受损结构，因其组成可随适应恶劣条件而变化，在抗应激中发挥重要作用。其次，热休克处理引起的膜组成和流动性变化与对生物和非生物表面的黏附之间没有关系。
