浆水中降胆固醇乳酸菌的筛选及其功能特性

Screening and functional properties of cholesteroldegrading lactic acid bacteria from Jiangshui

【目的】获取高降胆固醇菌种并明确其功能特性。【方法】以浆水为实验材料,利用高降胆固醇培养基筛选出降胆固醇的乳酸菌,并研究高降胆固醇菌株的耐酸、耐盐等功能特性,而后采用生理生化特性鉴定和16S r DNA分子生物学鉴定结合的方法鉴定高降胆固醇菌株的种属。【结果】所分离的乳酸菌都有一定的降胆固醇能力,其中有4株菌对培养物中胆固醇的降解率大于75%,经鉴定发现有乳酸乳球菌乳亚种(Lactococcus lactis subsp.lactis)1株,乳酪短杆菌(Brevibacterium casei)2株,棉籽糖乳球菌(Lactococcus raffinolactis)1株。【结论】从浆水中筛选出4株高降胆固醇乳酸菌,且其功能性质良好,有进一步开发利用价值。

[Objective] We intended to obtain and characterize lactic acid bacteria with high capacity of cholesteroldegrading. [Methods] We chose Jiangshui as the experimental material,screened lactic acid bacteria by the culture medium with high cholesterol,and studied other features of lactic acid bacteria like salt-tolerant,acid resistance,then identified the species of lactic acid bacteria by combining physiological and biochemical methods and 16 S r DNA sequence.[Results]All lactic acid bacteria isolated had the capacity of cholesterol-degrading to some extent. There were 4 strains had high cholesterol-degrading rate（ 75%）. Four strains were Lactococcus lactis subsp. lactis,two were Brevibacterium casei,and one was Lactococcus raffinolactis. [Conclusion] Cholesterol-degrading lactic acid bacteria were screened from Jiangshui,with application potential for cholesterol degradation.