从巴马长寿人群肠道中分离得到51株乳酸菌,通过体外试验筛选出16株降胆固醇及甘油三酯能力较强的菌株,降解率均分别大于30.00%和5.00%,其中Lr10的胆固醇及甘油三酯降解率显著高于其他菌株(P<0.05),分别为61.90%和37.22%;通过模拟人工胃液及胆盐耐受试验发现,16株菌株中Lr10的耐酸耐胆盐能力较强,其在pH为3.0的人工胃液及胆盐浓度(w/v)为0.0%、0.1%、0.3%及0.5%的MRS培养基中存活率分别为71.43%、66.37%、64.55%及19.12%;经API试剂条及16S rDNA测序将Lr10鉴定为鼠李糖乳杆菌;将Lr10制成脱脂乳悬浮液及脱脂发酵乳进行体内降血脂试验,结果表明,鼠李糖乳杆菌Lr10及其脱脂发酵乳在体内具有明显的降血脂效果。

In this study,51 strains of lactic acid bacteria were isolated from Bama longevity population gut. Among them,16 strains were selected for their abilities to lower cholesterol and riglycerids with lowering rates of more than 30. 00% and 5. 00%,respectively. The Lr10 was significantly effective than others( P < 0. 05),in which the lowering rates reached 61. 90% and 37. 22%,respectively. The Lr10 had strong ability of bile-salt and low pH tolerance. Its survival rates were 71. 43%,66. 37%,64. 55% and 19. 12% in pH 3. 0 simulated gastric juice and MRSbroth with 0. 3%,0. 5%,and 1. 0% bile salt,respectively. It was identified as Lactobacillus rhamnosus by API and 16s rDNA sequence alignment. The Lr10 was prepared into skim milk suspension and skim fermented milk to test its lipid-lowering ability in vivo,the result showed that Lr10 and its fermented milk had a remarkable lipid-lowering effect in vivo.