东北传统发酵食品中高抗氧化活性植物乳杆菌的筛选及体外耐受性分析

为了获得高抗氧化活性植物乳杆菌,从东北传统发酵食品辣椒酱、臭豆腐、粘面子中筛选出75株植物乳杆菌。将75株植物乳杆菌分为无细胞上清液、完整细胞、无细胞提取物三个组分,以DPPH和ABTS⁺自由基清除率为指标对菌株进行筛选,分析不同指标间的相关性,并评价菌株耐酸、耐胆盐能力及对抗生素的敏感性。结果表明,23株菌株表现出较好的抗氧化活性,无细胞上清液对DPPH和ABTS自由基清除率均大于90%,完整细胞和无细胞提取物对这两种自由基清除率均大于30%。植物乳杆菌的三个组分在清除DPPH自由基中存在相关性,无细胞上清液在DPPH和ABTS⁺两种评价方法上存在极显著相关性。其中有5株植物乳杆菌(D2、H8、L20、L11和A2)在pH2.0环境中存活率均大于59%,在0.3%胆盐中的存活率均大于93%,对7种抗生素敏感性较强。因此,这5株植物乳杆菌对于开发抗氧化作用的功能食品具有潜在的应用价值。

Screening and in Vitro Tolerance Analysis of Lactobacillus plantarum with High Antioxidant Activity in Traditional Fermented Food of Northeast China

In order to obtain Lactobacillus plantarum with high antioxidant activity,75 strains of Lactobacillus plantarum were screened from traditional fermented food in northeast China,including capsicum sauce,stinky tofu and sticky face. 75 strains of Lactobacillus plantarum were divided into acellular supernatant,intact cell and acellular extract three components. The DPPH and ABTS+ free radical scavenging rate were used to screen the strains,and the correlation between different indicators was analyzed. The acid and bile salt tolerance of the strain and its sensitivity to antibiotics were evaluated. The results showed that 23 strains showed good antioxidant activity. The scavenging rates of DPPH and ABTS+ free radicals in acellular supernatant were more than 90%,and those of intact cells and acellular extracts were more than 30%. The three components of Lactobacillus plantarum were correlated in scavenging DPPH free radicals,while the cell-free supernatant was significantly correlated in DPPH and ABTS+ evaluation methods. Among them,5 strains of Lactobacillus plantarum(D2,H8,L20,L11 and A2)survived more than 59% at pH2.0 and 93% in 0.3% bile salt. They were highly sensitive to 7 antibiotics. Therefore,these five strains of Lactobacillus plantarum would have potential application value in the development of functional food with antioxidant activity.