具抗氧化活性乳酸菌的筛选

Screening of antioxidative lactic acid bacteria

以体外过氧化氢耐受能力为指标,从发酵食品中筛选出2株能够耐受1mmol/L浓度过氧化氢的乳酸菌,两株细菌的耐过氧化氢能力与L. rhamnosusGG的耐过氧化氢能力相当。研究了两株乳酸菌完整细胞和无细胞提取物的DPPH自由基和羟自由基清除能力。结果表明,菌体浓度为109mL-1的L1001完整细胞和无细胞提取物的DPPH自由基清除率分别为36.2%和37.9%,同样浓度的F12完整细胞和无细胞提取物对DPPH自由基的清除率分别为24.4%和27.0%;清除羟自由基实验表明,细胞浓度为109mL-1的细胞清除羟自由基能力与同体积的浓度为1mmol/L抗坏血酸相当,L1001的羟自由基清除能力优于F12。利用API鉴定系统L1001菌株被鉴定为植物乳杆菌Lactobacillus plantarum L1001。

Two strains of lactic acid bacteria were isolated from different fermented foods based on the in vitro resistance to hydrogen peroxide. The H2O2-resistant capacity is similar to that of Lactobacillus rhamnosus GG. Free radical-scavenging ability of two isolates were studied. The results showed that the α, α-diphenyl-β-picrylhydrazyl （DPPH） free radical-scavenging ratio by intact cells and cell-free extracts of a L1001 10^9 mL^-1 lactic acid bacteria were 36.2% and 37.9% respectively, and those of 10^9 mL^-1 F12 cell suspension were 24.4% and 27.0%, respectively; The hydroxyl radicals-eliminating ability of 109 mL^-1 cells were equivalent to that of lmmol/L ascorbic acid of the same volume. The strain of L1001 was identified as Lactobacillus plantarum L1001 by the API method.