胆盐水解酶基因在植物乳杆菌KLDS1.0386中的表达研究

Expression of Bile Salt Hydrolase Genes in Lactobacillus plantarum KLDS1.0386

摘要:

本文从转录水平上研究了四种胆盐水解酶基因在植物乳杆菌KLDS1.0386中不同生长阶段的表达情况，并且分别以不同浓度的牛磺脱氧胆酸盐和甘氨脱氧胆酸盐为底物，以16s rRNA作为内参基因，利用实时荧光定量PCR技术研究不同浓度底物下的胆盐水解酶基因（bsh1、bsh2、bsh3、bsh4）表达的变化规律。结果显示，内参基因和目的基因的扩增效率均在90%~105%之间，说明目的基因的表达量可以被很好的反应出来。通过实时荧光定量PCR结果分析可知，植物乳杆菌KLDS1.0386中的4种胆盐水解酶基因随着生长时间的延长，表达量显著增加，而且在两种胆盐中都表达，基因表达量都被不同剂量（1%、2%、3%）的胆盐上调，上升幅度随着胆盐浓度的增加表现出极显著的增加趋势，而且胆盐不同，同浓度时每个基因的表达量也各不相同，在甘氨脱氧胆盐中的表达量普遍高于牛磺脱氧胆盐。

Abstract:

The expression levels of four key genes encoding bile salt hydrolase in Lactobacillus plantarum KLDS1.0386 were investigated at the transcriptional level during the different growth phases. Different concentrations of taurodeoxycholate and glycodeoxycholate were used as substrates, 16s rRNA gene was used as the internal standard, and real-time quantitative polymerase chain reaction (PCR) method was used to detect the variations in the expression of the bile salt hydrolase genes (bsh1, bsh2, bsh3, and bsh4) in the presence of taurodeoxycholate and glycodeoxycholate at different concentrations. The results showed that the amplification efficiencies of the reference gene and target genes were in a range of 90~105%, indicating that the expression levels of the target genes were well reflected. The real-time quantitative PCR results showed that the expression levels of four bile salt hydrolase genes increased significantly when the incubation time was prolonged. bsh1, bsh2, bsh3, and bsh4 were expressed in two types of bile salts. The expression levels were upregulated by bile salts at different concentrations (1%, 2%, and 3%), and the increment exhibited an extremely significant upward trend with increasing bile salt concentrations. Additionally, the expression level of each gene was different in the presence of two different bile salts at the same concentration. The gene expression level was generally higher in the presence of glycodeoxycholate (GDC) than that in the presence of taurodeoxycholate (TDC).