Marielle Bouix, Sarrah Ghorbal
AgroParistech-INRA UMR 782, Génie et Microbiologie des Procédés Alimentaires, 78850 Thiverval-Grignon, France.
AgroParistech-INRA UMR 782, Génie et Microbiologie des Procédés Alimentaires, 78850 Thiverval-Grignon, France.
J Microbiol Methods. 2017 Dec;143:50-57. doi: 10.1016/j.mimet.2017.10.005. Epub 2017 Oct 16.
It can be interesting to evaluate the cytoplasmic membrane fluidity of bacteria in order to understand the impacts of stresses during processing. Traditionally, membrane fluidity was assessed by fluorescence anisotropy measured by spectrofluorimetry, but this method does not make it possible to reveal the heterogeneity of bacterial populations. Flow cytometry, as opposed to spectrofluorimetry, has the ability to simultaneously detect different sub-populations. We developed a new method to measure the fluorescence anisotropy of bacterial membranes using flow cytometry. This technique, coupled with viability/mortality/fluidity co-staining, now allows us to assess the membrane fluidity of viable, damaged and dead cells. Then, we show that membrane of viable bacterial cells becomes more and more rigid during batch culture, culminating in the death of the cells. This new flow cytometric method therefore opens new perspectives to study changes and adaptations in bacterial membranes of viable cells depending on the micro-environment during fermentation or stress applications.
评估细菌的细胞质膜流动性以了解加工过程中压力的影响可能会很有趣。传统上，膜流动性是通过荧光分光光度法测量的荧光各向异性来评估的，但这种方法无法揭示细菌群体的异质性。与荧光分光光度法不同，流式细胞术能够同时检测不同的亚群。我们开发了一种使用流式细胞术测量细菌膜荧光各向异性的新方法。这项技术与活力/死亡率/流动性共染色相结合，现在使我们能够评估活细胞、受损细胞和死细胞的膜流动性。然后，我们表明在分批培养过程中，活细菌细胞的膜变得越来越僵硬，最终导致细胞死亡。因此，这种新的流式细胞术方法为研究活细胞的细菌膜在发酵或施加压力期间根据微环境的变化和适应性开辟了新的视角。
