Pulsed electric field (PEF) processing has been developed and applied in food industry for several purposes. In this study we used PEF for increasing the intracellular trehalose content in Lactobacillus plantarum WCFS1. Our results indicated that it is possible to increase intracellular trehalose content in Lactobacillus plantarum WCFS1 to ~100 mM with 75% survival when applying a PEF treatment with an electric field strength of 7.5 kV/cm. Fluorescence staining of PEF-treated cells with propidium iodide (PI) and SYTO 9 showed that at 7.5 kV/cm only a small fraction (23%) of the cells had a permeated membrane by this PEF treatment, of which approximately half had an irreversible permeated membrane. Resealing of the pores in the membrane for PI uptake was very fast, in the order of seconds. These results indicate that PEF treatment is promising for increasing intracellular trehalose, but further optimization is required to increase the trehalose content in all cells.

Industrial relevance

The market for probiotics is growing. Probiotic survival during processing steps such as spray drying is essential for their beneficial effect. We studied pulsed electric field treatment as a method to increase the intracellular trehalose content in L. plantarum WCFS1 which could enhance bacterial robustness during processing. This increased bacterial robustness may again contribute to more energy efficient processing routes of probiotic foods.

中文翻译：

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脉冲电场增加植物乳杆菌WCFS1中细胞内海藻糖含量

脉冲电场（PEF）处理已经开发出来，并在食品工业中用于多种用途。在这项研究中，我们使用PEF来增加植物乳杆菌WCFS1中的细胞内海藻糖含量。我们的结果表明有可能增加植物乳杆菌中细胞内海藻糖的含量使用电场强度为7.5 kV / cm的PEF处理时，WCFS1至〜100 mM，存活率为75％。用碘化丙锭（PI）和SYTO 9对PEF处理的细胞进行荧光染色，结果表明，通过PEF处理，在7.5 kV / cm的条件下，只有一小部分（23％）的细胞具有渗透膜，其中大约一半具有不可逆的渗透膜。膜中的孔被PI吸收重新密封非常快，大约数秒。这些结果表明PEF治疗有望增加细胞内海藻糖，但是需要进一步优化以增加所有细胞中的海藻糖含量。

行业相关性

益生菌的市场正在增长。益生菌在加工步骤（例如喷雾干燥）中的存活对其有益效果至关重要。我们研究了脉冲电场处理作为增加L中细胞内海藻糖含量的方法。植物WCFS1可能在加工过程中增强细菌的鲁棒性。这种增加的细菌健壮性可能再次有助于益生菌食品更节能的加工路线。