具有降胆固醇能力的人源乳酸菌筛选

分离筛选出长寿人群肠道中具有益生功能的乳酸菌,并研究其体外降解胆固醇能力。结果表明分离获得的80株乳酸菌中,9株菌在模拟胃液中培养3 h的存活率较高,分别为26.60%、24.30%、22.50%、16.72%、46.61%、16.10%、19.80%、19.60%、17.80%,在0.30%、0.50%及1.00%的胆盐培养基中存活率最高的菌株为o2,存活率分别为21.31%、13.35%及12.43%;9株菌对氨苄青霉素、青霉素G、氯霉素敏感,对四环素、利福平、环丙沙星敏感或中度敏感;9株菌对三株致病菌均有抑制作用,其中V9、o2分别对沙门氏菌、金黄色葡萄球菌抑制能力较强,抑菌圈直径分别为12.00 mm、11.40 mm,9株菌对大肠杆菌的抑制作用普遍较强,抑菌圈直径均大于7.00 mm;9株菌中f10、o2、T1及V9的胆固醇降解率较高,分别为45.85%、40.76%、41.70%、42.87%,经生理生化试验及16S rDNA测序鉴定分别为屎肠球菌、食窦魏斯氏菌、干酪乳杆菌及发酵乳杆菌,是良好的辅助降血脂候选菌株。

Screening of Cholesterol-reducing Lactic acid bacteria from Human Origin

Lactic acid bacteria (LAB) with probiotic were isolated and screened from intestinal tract of longevity crowd, and the ability of cholesterol-reducing in vitro were investigated. The results showed that nine of eighty strains had high survival rates in simulated gastric juice for 3 hours, being of 26.60%, 24.30%, 22.50%, 16.72%, 46.61%, 16.10%, 19.80%, 19.60% and 17.80%, respectively. The survival rates of o2 were the highest, which were 21.31%, 13.35%, 12.43% respectively in 0.3%, 0.5% and 1.0% bile salt. Nine strains were sensitive to ampicillin, penicillin G, chloramphenicol, and sensitive or moderately sensitive to tetracycline, rifampicin and ciprofloxacin. They had bacteriostatic activity against Salmonella, Staphylococcus aureus and Escherichia coli. The bacteriostatic activities of V9 and o2 to Salmonella, Staphylococcus aureu were higher. The inhibition diameters were 12.00 mm and 11.40 mm respectively, and all the nine strains had high bacteriostatic activity to Escherichia coli, with the inhibition diameters of more than 7.0 mm. The cholesterol-reducing rates of f10, o2, T1 and V9 were 45.85%, 40.76%, 41.70%, 42.87%, respectively, higher than other strains, which were identified as Enterococcus faecium, Weissella Cibaria, Lactobacillus casei and Lactobacillus fermentum by physiological and biochemical test as well as 16srDNA sequence alignment. These strains could be good candidate probiotics strains for auxiliary hypolipidemic.