García María Teresa, Marínez Cañamero Magdalena, Lucas Rosario, Ben Omar Nabil, Pérez Pulido Rubén, Gálvez Antonio
Area de Microbiología, Departamento de Ciencias de la Salud. Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén, Spain.
Int J Food Microbiol. 2004 Jan 15;90(2):161-70. doi: 10.1016/s0168-1605(03)00051-5.
Enterocin EJ97 from Enterococcus faecalis EJ97 showed a concentration-dependent antimicrobial activity against Listeria monocytogenes CECT 4032. Activity of enterocin EJ97 against L. monocytogenes CECT 4032 increased slightly at 4 degrees C, and cold-adapted cells did not show any increased resistance. Sensitivity of L. monocytogenes CECT 4032 to enterocin EJ97 was not modified by the addition of sodium benzoate, sodium acetate, NaCl or sodium tripolyphosphate. Anti-listeria activity was enhanced by potassium nitrate, and especially by sodium nitrite at concentrations of 50 microg/ml or above. E. faecalis EJ97 produced bacteriocin activity during cocultivation with L. monocytogenes CECT 4032 at 37 degrees C and also at 15 degrees C, but not at 4 degrees C. Growth of L. monocytogenes CECT 4032 was inhibited by bacteriocin produced during cocultivation at 37 and 15 degrees C, and the degree of inhibition was influenced by the incubation temperature and the initial concentrations of enterococci and listeria. E. faecalis EJ97 also produced bacteriocin during cocultivation in half-skimmed milk, although its capacity to control L. monocytogenes was limited to populations of 10(3) CFU/ml or lower.
来自粪肠球菌EJ97的肠球菌素EJ97对单核细胞增生李斯特菌CECT 4032表现出浓度依赖性抗菌活性。肠球菌素EJ97对单核细胞增生李斯特菌CECT 4032的活性在4℃时略有增加，且冷适应细胞未表现出任何抗性增加。添加苯甲酸钠、醋酸钠、氯化钠或三聚磷酸钠不会改变单核细胞增生李斯特菌CECT 4032对肠球菌素EJ97的敏感性。硝酸钾可增强抗李斯特菌活性，尤其是浓度为50μg/ml及以上的亚硝酸钠。粪肠球菌EJ97在与单核细胞增生李斯特菌CECT 4032于37℃以及15℃共培养期间产生细菌素活性，但在4℃时不产生。单核细胞增生李斯特菌CECT 4032的生长受到37℃和15℃共培养期间产生的细菌素的抑制，抑制程度受培养温度以及肠球菌和李斯特菌初始浓度的影响。粪肠球菌EJ97在半脱脂牛奶中共培养期间也产生细菌素，尽管其控制单核细胞增生李斯特菌的能力仅限于10³CFU/ml或更低的菌量。
