降胆固醇乳酸菌的筛选和分析比较

目的比较7株乳酸菌各项生理特性,筛选高效、安全降解胆固醇的益生菌株,为后期开发应用奠定基础。方法对选定菌株依次进行体外降胆固醇、胆盐水解酶(BSH)活力、人工胃肠液及胆盐耐受性、细胞粘附性能的测定和比较,并分析抗生素耐药性和抑制病原菌活性,最后利用16S rRNA基因测序确定细菌种属。结果不同菌株各项生理指标存在差异。其中菌株ZL-2、JQI-7和PC-26的BSH酶活分别为0.010、0.015和0.030 U,可高效清除体外胆固醇,3株菌体外降解胆固醇率在58%以上;并且耐酸、耐胆盐,具备较好的HT--29细胞粘附性,不存在抗生素耐药性,可有效抑制大肠埃希菌、金黄色葡萄球菌、铜绿假单胞菌和阴沟肠杆菌生长。结论菌株ZL-2、JQI-7和PC-26满足降胆固醇益生菌株的生物学特性,可用于进一步研究和开发。

Screening and comparison of cholesterol-lowing Lactobacillus strains

Abstract: Objective To analyze the biological characteristics of seven Lactobacillus strains, screen cholesterol-lowering strains with safety and high-efficiency, and lay foundation for industrial production. Methods The capabilities of lowering cholesterol in vitro, activity of bile salt hydrolase (BSH), tolerance to artificial gastric intestinal juice and bile salt, cell adhesion capacity, tolerance to antibiotics and antimicrobial activity of the selected strains were detected and compared. 16S rRNA sequencing was conducted to identify the Lactobacillus species. Results Among the seven strains, the BSH activities of ZL-2, JQI-7 and PC-26 were 0.010 U, 0.015 U and 0.030 U, respectively. The degradation rates of cholesterol by the three strains were over 58%. They showed good tolerance to acid and bile salt, were sensitive to 13 antibiotics, and demonstrated strong adhesion to HT-29 cells and inhibitory effect to Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterobacter cloacae. Conclusion The strains ZL-2, JQI-7 and PC-26 can be further applied in the industrial production since they have good biological characteristics and significant cholesterol-lowering effect.