植物乳杆菌脂肪酸构成与胆盐耐受性的相关性分析

Correlation Analysis of the Relationship between Fatty Acid Composition and Bile Resistance in Lactobacillus plantarum Strains

为分析菌株的脂肪酸构成与胆盐耐受能力的关系,本文对8株分离自发酵乳制品的植物乳杆菌展开研究。以菌体在含有0.3%胆盐的MRS肉汤培养基中的对数存活率作为其胆盐耐受能力评价的指标,并通过气相色谱法分析各菌株的脂肪酸构成。Pearson相关性分析表明,菌体中棕榈酸(C16:0)和19碳环丙烷脂肪酸(cyc C19:0)含量与其胆盐耐受能力呈显著正相关(P<0.05),而豆蔻酸(C14:0)和油酸(C18:1)含量与菌体胆盐耐受能力呈显著负相关(P<0.05)。细胞完整性评价表明:胆盐敏感型菌株在胆盐环境中具有较弱的细胞完整性,而这一指标受脂肪酸构成影响。本研究结果表明:特定脂肪酸对天然来源的菌体而言,在胆盐环境中维持细胞完整性和提高胆盐耐受性方面扮演着重要角色。

Eight Lactobacillus plantarum strains separated from fermented dairy foods were used to investigate the relationship between fatty acid composition and bile resistance. Bile resistance was evaluated by the bacteria＇s survival in Log cycle when challenged in an MRS broth supplemented with 0.3% bile salt, and the fatty acid compositions of each strain were detected by gas chromatography. Pearson＇s correlation analysis showed that the content levels of palmitic acid （C16：0） and C-19 cyclopropane fatty acid （cycCtg：0） had significant positive relations （P〈0.05） with bile resistance. The content levels of myristic acid （C14：0） and oleic acid （C18：1） had significant negative correlations （P〈0.05）. Cell integrity evaluation implied bile-sensitive strains owned weaker cell integrity, which was affected by fatty acid composition. These results showed the importance of specific fatty acids for bile resistance and maintaining cell integrity in strains from natu- ral food origins.