蜂蜜中艾皮斯乳杆菌A9（Lactobacillus apis A9）的分离鉴定及其对铅的吸附作用

Identification of Lactobacillus apis A9 Isolated from Honey and Quantitation of its Lead Adsorption

摘要:

为了探究蜂蜜中乳酸菌的益生特性，从蜂蜜中分离纯化出一株革兰氏阳性菌，结合菌落和菌体特征、生理生化反应以及16S rDNA测序技术分析，鉴定该菌为艾皮斯乳杆菌（Lactobacillus apis）。安全性实验表明，该菌株A9不溶血，不水解明胶，不还原硝酸，无氨基酸脱羧能力，对青霉素等9种抗生素敏感。益生实验结果显示该菌有高自聚集率（93.37%）和较高的疏水率（48.71%），pH值3的环境下培养3 h存活率为43.67%，在1 wt.%胆酸钠溶液、6 wt.% NaCl溶液、25 wt.%葡萄糖溶液中分别培养24 h后，存活率分别为96.48%、68.27%、88.57%。表明该菌具有很强的耐酸耐胆盐和耐高渗能力。该菌吸附重金属铅的结果显示，对Pb2+ 的吸附率高达55.53%。铅占菌体表面的元素百分比为5.90%。红外结果表明，菌体表面的羟基、氨基与铅离子发生了相互作用，造成菌体蛋白的α螺旋和β转角增加，β折叠减少。结果表明，从蜂蜜中筛选出的Lactobacillus apis A9具有良好的安全性、益生功能及良好的重金属铅吸附能力，为蜂蜜中乳酸杆菌的开发利用，提供了新的思路。

Abstract:

In an investigation of the probiotic properties of lactic acid bacteria in honey, a gram-positive bacterium was isolated from honey and purified. Based on its colony and cell morphology, physiological and biochemical responses, and 16S rDNA sequencing analysis, the bacterium was identified as Lactobacillus apis A9. This strain was found to be negative for hemolysis, gelatin hydrolysis, nitrate reduction, and amino acid decarboxylation, and susceptible to nine antibiotics, including penicillin. In probiotic experiments the bacterium displayed a high self-aggregation rate (93.37%) and a relatively high hydrophobicity rate (48.71%). It exhibited 43.67% survival after incubation for 3 h at pH 3.0. After 24 h of incubation in solutions of 1 wt.% sodium deoxycholate, 6 wt.% sodium chloride, and 25 wt.% glucose, the survival rates of the bacterium were 96.48%, 68.27%, and 88.57%, respectively. These results indicate that strain A9 possesses strong resistance to acid, bile salts, and hyperosmotic stress. The bacterium displayed a lead (Pb2+) absorption rate of 55.53%. Lead accounted for 5.90% of the bacterium’s surface-displayed elements. Infrared results revealed that hydroxyl and amino groups on the bacterium’s surface interact with lead ions, leading to an increase in α-helices and β-turns in the bacterium’s proteins and a decrease in β-sheets. In summary, L. apis A9 isolated from honey exhibits good safety, probiotic function, and lead adsorption capacity. This study provides new insights into the development and utilization of lactobacilli in honey.