两株自选乳酸菌的益生特性

研究了两株自选乳酸菌的益生特性,为其应用于果蔬汁乳酸发酵的功能性饮料研制提供理论依据.以自选植物乳杆菌R23和干酪乳杆菌R35为目标菌,以德氏乳杆菌保加利亚亚种6045为对照菌,考察各菌对模拟胃液酸度和肠道胆盐的抗逆性以及凝集能力、表面疏水性等黏附性能,并评价其发酵液对超氧阴离子和羟基自由基的清除能力等体外抗氧化功能.结果表明:两菌株对酸度和胆盐的耐受能力均优于对照菌,植物乳杆菌R23的抗逆性最强,能耐受pH值2.5、胆盐质量浓度5 g.L-1.干酪乳杆菌R35的黏附能力强,而植物乳杆菌R23疏水性较强而凝集能力较弱.各菌株的胞外代谢产物均有抗氧化能力,以植物乳杆菌R23为最强,其培养24 h后的发酵液对超氧阴离子自由基和羟自由基的清除率达77.8%和80.94%,分别比对照菌高36.72%和5.81%.

Probiotic Properties of Two Self-chosen Lactobacillus Strains

The probiotic properties of two self-chosen lactobacillus strains were studied to provide the theorerical foundation for the research and development of lactic acid fermentation beverage.The stress resistance of lactobacillus plantarum R23 and lactobacillus casei R35 were investigated in a simulated enviroment of gastric acidity and bile salts,the adhesion ability were determined such as their aggregation properties and cell-surface hydrophobicity.The antioxidation of the broth including the scavenging effects on superoxide radical and hydroxyl radical was evaluated in vitro.The results showed that the stress resistance of the both strains was superior to the control group lactobacillus delbrueckii subsp 6045.The tolerance of pH value was 2.5 and bile salt was 5 g·L-1 for the lactobacillus plantarum R23,showing the strongest stress resistance.The adhesion of the lactobacillus casei R35 was the strongest in contrast with the control group,the hydrophobicity of the lactobacillus paltarum R23 was stronger,while its aggregation properties was weaker.The extracellular products of three strains had antioxidant capacity after 24 h culture,while lactobacillus paltarum R23 showed the best.Its scavenging rate to superoxide radical and hydroxyl radical was 77.8% and 80.94% respectively,which was 36.72% and 5.81% higher than the control group.