【摘要】 采用稀释涂布法和三区划线法从13种花粉中分离筛选产胞外多糖(exopolysaccharide,EPS)的乳酸菌，对筛选菌株进行形态学观察、分子生物学鉴定及生理生化实验，并评价其耐酸、耐胆盐、耐尿素、耐NaCl等特性。结果表明，从刺槐花粉中分离筛选出1株产胞外多糖的菌株YF，其胞外多糖产量为(5.213 5±0.034 5)g/L。经鉴定该菌株为昆氏乳杆菌(Apilactobacillus kunkeei)，革兰氏阳性菌，可广泛利用蔗糖、果糖、鼠李糖等8种不同碳源。其最佳生长时间为21 h，具有良好的环境抗逆性，最适生长pH值、NaCl质量分数、尿素质量分数、猪胆盐质量分数分别为6、2%、2%和0.4%。该研究可为拓展益生菌资源库及开发功能性EPS产品奠定理论基础。更多还原

【Abstract】 Exopolysaccharide(EPS)-producing lactic acid bacteria were isolated from 13 types of pollen using the dilution plating and three-zone streak plate methods. The isolated strains were subjected to morphological observation, molecular biological identification, and physiological-biochemical characterization. Their tolerance to acid, bile salts, urea, and NaCl was evaluated. The results indicated that one EPS-yielding strain, designated YF, was isolated from Robinia pseudoacacia pollen. The EPS yield of this strain was(5.213 5 ± 0.034 5) g/L. Strain YF was identified as Apilactobacillus kunkeei, a Gram-positive bacterium. This strain demonstrated the ability to extensively utilize eight different carbon sources, including sucrose, fructose and rhamnose. Its optimal growth time was 21 h, and it exhibited strong environmental resilience. The optimal conditions for its growth were a pH of 6, an NaCl content of 2%(m/m), a urea content of 2%(m/m), and a porcine bile salt content of 0.4%(m/m). This study lays a theoretical foundation for expanding the probiotic resource library and developing functional EPS products.更多还原