产广谱抑菌活性物质乳酸菌的分离筛选

目的]研究筛选可产广谱抑菌性活性物质的乳酸菌,为食品保存方法的研究提供参考。方法]以自制泡菜为材料,用含有溴甲酚紫的BCP培养基进行初筛,用添加CaCO3的MRS培养基制备上清液,复筛得到对4种指示菌有抑制作用的菌株,再经过排除酸和过氧化氢的抑制作用,且经过热稳定性试验和活性持效期试验筛选抑菌菌株。结果]通过初筛和复筛,得到对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌和酵母菌有抑制作用的菌有5株。其中菌株LP-6排除酸和过氧化氢的抑菌活性后仍具有明显的抑菌活性,且经过热稳定性试验,活性持效期试验,发现LP-6菌株的发酵上清液仍具有明显的抑菌活性。结论]初步判断菌株LP-6产细菌素类抑菌物质,可应用于食品工业中。

Isolation of Lactobacillus with Broad-spectrum Antimicobial Activity

Objective ] The study aimed to isolate Lactobacillus with broad-spectrum antimicobial activity to provide scientific references for the research of methods of food preservation. Method] The homemade pickles were taken as the material to preliminarily isolate LactobaciUus in BCP culture medium containing bromocresol purple, then Lactobacillus supernatant was prepared using MRS mediumcontaining CaCOz. Af- terwards, the strains having inhibitory effects on four indicator bacteria were obtained, and then the strain with the best antibacterial activity （the antibacterial activity of acid and H2O2 were excluded） was isolated through thermal stability test and activity persistence test. Result] Through two times of isolation, it was found that five strains had inhibitory activity to bacteria, like Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Saccharomyces cerevisiae. Among them, strain LP-6 still presented obvious antibacterial activity after the antibacterial ac- tivity of acid and H202 were excluded. Moreover, the antibacterial activity of strain LP-6 heated or preserved for three months was also obvi- ous. F Conclusion] Strain LP-6 could release some bacteriocin.