低聚糖对乳酸菌抗氧化胁迫能力的影响

目的:研究GOS（低聚半乳糖）和XOS（低聚木糖）对乳酸菌（L.bulgaricus Fn009）耐H2O2胁迫能力的影响。方法:利用H2O2建立氧化应激模型,以MTT法（四甲基偶氮唑盐比色法）检测GOS和XOS对乳酸菌存活率影响,以流式细胞技术检测GOS和XOS对乳菌细胞膜完整性的影响,并测定GOS和XOS对乳酸菌抗氧化酶活力和应激蛋白基因表达水平的影响。结果:H2O2胁迫条件下,GOS和XOS干预组乳酸菌存活率提高了1.83～1.96倍,细胞膜完整率分别提高了17%和13%,T-SOD和GSH-Px酶活力均显著上升（p<0.05）,Dnak、GroEL和Gsp65应激蛋白基因的表达水平显著下调（p<0.05）。结论:GOS和XOS能够提高乳酸菌自身的抗氧化活力,降低H2O2胁迫对菌体细胞膜的损伤程度,增强乳酸菌对氧化胁迫的抗性。 

Influence of oligosaccharides on the antioxidant activities and tolerance capacity of Lactobacillus to oxidative stress

Objective:To evaluate the effects of galacto-oligosaccharide (GOS) and xylo-oligosaccharide (XOS) on the antioxidant activity and tolerance capacity of Lactobacillus under H2O2 stress. Methods:Under H2O2 stress, the survival of Lactobacillus was examined by MTT method and the integrity of cell membrane was examined by flow cytometry. The effects of GOS and XOS on the activity of antioxidant enzyme and expression of stress protein related gene in Lactobacillus were also evaluated. Results:Under the H2O2 stimulus, GOS and XOS could enhance the survival rate of Lactobacillus, which improved by 1.83～1.96 times. And the cell membrane integrity was increased by 17% and 13% respectively. Both oligosaccharides were able to enhance the activity of antioxidant enzyme and reduce the expression level of stress protein related gene in Lactobacillus. Conclusion:GOS and XOS are able to enhance the antioxidant activity and strengthen the resistance of Lactobacillus against oxidative stress.