乳酸菌MR25的筛选、鉴定及降胆固醇益生特性  

Isolation, Identification and Cholesterol-lowering Characteristics of Lactic Acid Bacteria MR25

作　　者：刘长建[1] 蒋本国[1] 姜波[1] 刘秋[1] 崔玉波[1] 

机构地区：[1]大连民族学院生命科学学院,辽宁大连116600

出　　处：《中国食品学报》2011年第8期42-46,共5页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(No.30671398);NSFC-KOSEF国际合作项目(No.30711140389)

摘　　要：通过气相色谱法,从萝卜干中共分离到31株具有清除培养基中胆固醇能力的乳酸菌,其中乳酸菌MR25的胆固醇清除率最高（42.48%）。通过形态观察、生理生化试验、糖发酵试验等,鉴定MR25为米酒乳杆菌。乳酸菌MR25具有酸耐受性、胆盐耐受性和一定的胆固醇降低能力。在pH2.0、培养2h条件下菌株浓度仍能达到106cfu/mL。加胆盐（0.3%~0.4%）对菌株生长量（OD值）的影响很小。热杀死和休眠的细胞能去除很少的胆固醇,分别是3.26mg/mL和8.42mg/mL,而生长的细胞去除的胆固醇达到44.06mg/mL。胆固醇去除与菌体的生长有一定的相关性。乳酸菌MR25去除胆固醇的机理是菌体对胆固醇的吸附作用,以及菌体在生长过程中对胆固醇的吸收利用。By GC Methods, total 31 strains of Lactic acid bacteria were isolated from dried turnip. All strains could remove cholesterol from media, in which strain MR25’ was highest（42.48%）. Based on morphological, physiological and biochemistry test, strainMR25 was identified as Lactobacillus sake. Strain MR25 showed acid resistance, bile salt tolerance and the cholesterol-reducing ability. The results indicated that MR25 survived at pH2 after 2 h culture and the living bacterial number could reach 106 cfu/mL, 0.3%～0.4% bile salt had no obvious effect on the growth of MR25. Cholesterol removed by dead and resting cells were 3.26 and 8.42 mg/mL compared with growing cells, which was 44.06 mg/mL. Cholesterol removal was definitely associated with growth of strain. The possible mechanisms for removal of cholesterol from media were proposed： assimilation of cholesterol during growth, and adsorbtion of cholesterol to the cell surface.

关 键 词：乳酸菌 分离鉴定 酸耐受性 胆盐耐受性 胆固醇清除 

分 类 号：TS201.3[轻工技术与工程—食品科学]