优良抗氧化能力发酵乳杆菌P13的筛选及其耐逆特性

Isolation and Identification of Lactobacillus fermentum Strain P13 with High Anti-oxidative Activity and Its Stress Tolerance Properties

目的:从传统发酵蔬菜中筛选出具有抗氧化功能的益生乳酸菌,为抗氧化功能产品的开发提供优良备选益生菌株。方法:从传统发酵蔬菜中分离出29株乳酸菌,测定分离菌株细胞的体外抗氧化能力(DPPH自由基清除率、还原活力、抗油脂过氧化能力、羟自由基清除能力)。以具有强抗氧化能力的益生菌鼠李糖乳杆菌ATCC53103)为参照菌株。综合4种体外抗氧化能力测定结果,筛选出1株具有强抗氧化能力的乳酸菌,命名为P13,经形态观察和16 S rDNA遗传学分析,把该菌株鉴定为发酵乳杆菌(Lactobacillus fermentum)。对该菌株耐逆特性的研究表明,该菌株的耐酸、耐胆盐和耐盐特性高于对照菌株,而对过氧化氢的耐受能力低于对照菌株。该菌株的溶血型是γ-型,不具有溶血活性。研究结果显示,P13具有优良的抗氧化能力和耐逆特性,可作为制备具有抗氧化功能食品和微生态制剂的备选优良菌株。

The present study aims to evaluate the anti-oxidative activity in vitro of lactic acid bacteria(LAB) isolated from naturally fermented vegetable and select candidates to be used as probiotic starters for the improvement of the traditional fermentation process and the production of newly added value functional foods. Twenty nine lactic acid bacteria(LAB) strains were isolated from traditional fermented vegetables. Compared with the reference strain Lactobacillus rhamnosus GG(ATCC53103), one strain with higher anti-oxidative activity was named P13 and screened by means of measuring anti-oxidative activity in vitro, including the 2,2-diphenyl-1-picrylhydrazyl scavenging activity, reducing power,hydroxyl radical scavenging ability and inhibition capability of lipid peroxidation. Strain P13 was identified as Lactobacillus fermentum by 16 S r DNA nucleotide sequencing and morphology analysis. Strain P13 also showed higher stress tolerance properties(acidity, bile, and osmotic pressure hydrogen peroxide) than L. rhamnosus GG. But the tolerance to hydrogen peroxide was lower than that of reference strain. In addition, the strain P13 exhibited γ-haemolytic activity. Overall, strain P13 is a promising probiotic candidate for preparations of functional foods and antioxidant supplements.