冷冻干燥对乳酸菌细胞膜通透性的影响

Impact of Membrane Permeability in Lactic Acid Bacteria During Freeze-drying

摘要:

对细胞膜通透性变化的研究是认识冷冻干燥过程对乳酸菌损伤机理的途径之一。用荧光探针检测冻干过程前后细胞内H+和Ca2+浓度的变化, 可以精确的表征细胞膜通透性的改变。利用荧光探针BCECF-AM和Fluo3-AM对德氏乳杆菌保加利亚亚种在冻干前后的细胞膜通透性进行研究, 并对比菌种在冻干过程中的活力损失, 发现细胞膜在冻干前后通透性有显著增加, 并与活力的损失成反相关关系。说明在冻干过程中细胞受到了生理性损伤, 细胞膜通透性的改变可能是导致乳酸菌在冻干过程中致死和失活的原因之一。

关键词:乳酸菌, 冷冻干燥, 荧光探针

Abstract:

Alteration of cell membrane permeability is speculated to be one of the damage mechanisms to Lactic Acid Bacteria during freeze-drying. It has been reported that the H+ and Ca2+ alteration may be accurately detected by using fluorescent probe. The Lactobacillus bulgaricus permeability is studied by using fluorescent probe BCECF-AM and Fluo3-AM. The membrane permeability has a significant increase which is anti-related to the loss of vitality. These results suggest that alteration in cell membrane permeability contributes to the physical damage, it may be one of the reasons that lead to the cell death and loss of activity.

Key words:Lactic acid bacteria, Freeze-drying, Fluorescent probe