酸汤中乳酸菌的鉴定及其耐酸、耐胆盐和抗氧化活性

采用16S rDNA基因序列对从酸汤中分离出的6株乳酸菌进行鉴定,并研究6株菌的耐酸和耐胆盐能力;同时以清除1,1-二苯基-2-苦基肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基和羟基自由基为指标,探究其体外抗氧化活性。结果表明,6株菌均为植物乳杆菌(Lactobacillus plantarum),可耐受pH2.5和0.3%质量分数的胆盐,且活菌数保持在107 CFU/mL以上,存活率大于87%;菌体浓度为108 CFU/mL时,6株菌对DPPH自由基的清除率在23%~35%之间,对羟基自由基的清除率在6%~16%之间。6株植物乳杆菌中,JMST-1兼具良好的耐酸、耐胆盐和一定的抗氧化能力,在耐酸、耐胆盐试验中存活率达到91%,对DPPH自由基和羟基自由基的清除率分别达到28.60%和15.44%。

Identification,Acid and Bile Salt Tolerance,and Antioxidant Ability of Lactic Acid Bacteria Isolated from Sour Soup

Six lactic acid bacteria strains isolated from the traditional sour soup were identified by 16S rDNA gene sequence analysis. Acid and bile salt tolerance of six isolates were studied. Antioxidant activity in vitro of six strains including 1,1-diphenyl-2-picrylhydrazyl(DPPH)radicals scavenging activity and hydroxyl radicals scavenging activity were measured. The results showed that six strains were Lactobacillus plantarum. The six strains exhibited desirable probiotic properties,showing over 107 CFU/mL of viable count and over 87% of survival rate after incubation at pH2.5 and in the presence of bile salt at 0.3%. When adjusting the concentration of strains to 108 CFU/mL,six strainss showed 23%~35% of DPPH radical scavenging rate and 6%~16% of hydroxyl radical scavenging rate. The strain L. plantarum JMST-1 showed a high level of survival rate in acid and bile tolerance tests(>91%)and desirable free radical scavenging activity(28.60% of DPPH free radicals and 15.44% of hydroxyl free radicals).