藏灵菇发酵乳中降胆固醇乳酸菌的分离及鉴定  

Isolation and identification of cholesterol-reducing lactic acid bacteria from Tibet kefir

作　　者：黄颖[1] 隋玉杰[1] 钟莉莉[1] 郑永晨[1] 

机构地区：[1]吉林大学第二医院中心实验室,吉林长春130041

出　　处：《吉林大学学报（医学版）》2010年第6期1181-1185,共5页Journal of Jilin University：Medicine Edition

基　　金：吉林省科技厅科研基金资助课题(20080821-1);吉林大学基本科研业务费项目资助课题(421030693429)

摘　　要：目的:筛选具有降胆固醇功能的乳酸菌菌株,为乳酸菌体外、体内的降胆固醇生理特性和机制研究奠定基础。方法:利用邻苯二甲醛法从源于藏灵菇发酵乳中的7株乳酸菌中筛选具有较高降胆固醇能力的乳酸菌菌株,并研究其耐酸性、耐胆盐活性、生长曲线、产酸特性及抑菌特性;结合生理生化实验及16SrRNA寡核苷酸碱基序列分析鉴定菌株。结果:筛选得到1株降胆固醇效果明显的乳酸菌LA1,胆固醇降解率达到50.36%,且呈现较好的耐酸性和耐胆盐活性,其中LA1在第10小时进入对数生长期,第18小时进入稳定期;其能在pH1.5的MRS培养基中存活至少3h,在含0.3%胆盐的MRS培养基中生长良好,经鉴定为嗜酸乳杆菌;抑菌实验表明:该菌株对大肠杆菌、金黄色葡萄球菌均有明显的抑制作用。结论:该菌株可作为后续体内活性和机制研究的原始菌株。Objective To obtain cholesterol-reducing lactic acid bacteria（LAB）from Tibet kefir,and lay the foundation for physical character and mechanism study of its cholesterol-reducing effect in vitro and in vivo. Methods The cholesterol-reducing ability was tested on 7strains of lactic acid bacteria isolated from Tibet kefir by the o-phthalaldehyde method.LA1strain was screened for its better cholesterol-reducing ability,then subjected to physiological and biochemical identification as well as 16SRNA sequencing,and the acid-and oxgall-resistance, growth curve,pH value and antimicrobial activity were studied.Results The strain of LAB（LA1）was obtained, which presented a comparatively high ability of cholesterol reducing.The strain also showed high acid resistance and bile salt tolerance.The time of LA1entering the logarithm phase of growth and stationary phase of growth was 10and 18hafter culture.The strain survived for at least 3hin the MRS broth with pH 1.5and grew well in the MRS broth containing 0.3%bile salt.The results of bacteria inhibition experiment showed that the separated lactic acid bacterium had remarkable bacteriostasis on the growth of E.coli and Staphylococcus aureus.The strain was identified to be Lactobacillus acidophilus by 16SrRNA sequencing.Conclusion The isolated LA1shows probiotic properties of cholesterol reduction,acid and bile tolerance and antimicobial activity.It can be used as primary strain for study on activity in vivo and mechanism.

关 键 词：藏灵菇 胆固醇 嗜酸乳杆菌 16SrRNA 

分 类 号：Q933[生物学—微生物学]