解淀粉芽孢杆菌胞外多糖对乳酸菌生长及代谢的调控作用

Effects of Bacillus amyloliquefaciens exopolysaccharides on proliferation and metabolism of lactic acid bacteria

研究解淀粉芽孢杆菌JN4的胞外多糖(exopolysaccharide, EPS-JN4)对乳酸菌生长及代谢的调控作用,有利于阐明EPS-JN4定向增殖乳酸菌的作用机制。采用PCR-变性梯度凝胶电泳技术分析EPS-JN4的定向增殖作用,并考察其对主要乳酸菌生长、主要代谢产物、肠道耐受性和表面疏水性的影响。EPS-JN4可以定向增殖罗伊氏乳杆菌,其对罗伊氏乳杆菌JN125的前期增殖速度较葡萄糖慢,但最高菌浓为葡萄糖的5.25倍,代谢产物中乳酸和醋酸含量则较葡萄糖分别降低了12.2%和32.4%。EPS-JN4增殖的罗伊氏乳杆菌JN125的肠道耐受性和表面疏水性显著提高,对其原因初步分析表明细胞膜蛋白和脂类物质含量提高了40.8%和105.7%,细胞膜组成中的十八碳脂肪酸和不饱和脂肪酸显著提高。EPS-JN4可以作为潜在的益生元,用于调节动物肠道健康。

This study aimed to investigate the effects of exopolysaccharides from Bacillus amyloliquefaciens JN4 (EPS-JN4) on the propagation and metabolism of probiotics. The specific proliferative effects of EPS-JN4 were analyzed by PCR-denaturing gradient gel electrophoresis, and their effects on the growth, metabolites, intestinal tolerance, and surface hydrophobicity of lactic acid bacteria were also determined. It was found that EPS-JN4 had a specific proliferative effect on Lactobacillus reuteri . Compared to glucose, the early proliferation rate of L. reuteri JN125 treated with EPS-JN4 was slower, but its highest biomass was 4.25 times higher. In addition, the contents of lactic acid and acetic acid reduced by 12.2% and 32.4%, respectively. The intestinal tolerance and surface hydrophobicity of EPS-JN4-treated L. reuteri JN125 significantly improved, which could be due to the protein and lipid contents in cell membranes increased by 40.8% and 105.7%, respectively. Besides, the proportions of 18 C fatty acids and unsaturated fatty acids in cell membranes significantly increased. In conclusion, EPS-JN4 can be used as a potential prebiotic to regulate the intestinal health of animals.