Cintas L M, Rodriguez J M, Fernandez M F, Sletten K, Nes I F, Hernandez P E, Holo H
Departamento de Nutrición y Bromatología III, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.
Appl Environ Microbiol. 1995 Jul;61(7):2643-8. doi: 10.1128/aem.61.7.2643-2648.1995.
Lactic acid bacteria were isolated from Spanish dry-fermented sausages and screened for bacteriocin production. About 10% of the isolates produced antimicrobial substances when grown on solid media, but only 2% produced detectable activity in liquid media. Strain L50, identified as Pediococcus acidilactici, showed the strongest inhibitory activity and was active against members of all of the gram-positive genera tested. The strain produced a heat-stable bacteriocin when grown at 8 to 32 degrees C but not at 45 degrees C. The bacteriocin was purified to homogeneity. Its mass was determined to be 5,250.11 +/- 0.30 by electrospray mass spectrometry. The N terminus of the bacteriocin was blocked for sequencing by Edman degradation, but a partial sequence of 42 amino acids was obtained after cleavage of the peptide by cyanogen bromide. The sequence showed no similarity to those of other bacteriocins. Pediocin L50 appears to contain modified amino acids but not lanthionine or methyl-lanthionine.
从西班牙干腌香肠中分离出乳酸菌，并筛选其细菌素的产生情况。约10%的分离株在固体培养基上生长时产生抗菌物质，但在液体培养基中只有2%产生可检测到的活性。鉴定为嗜酸乳杆菌的L50菌株表现出最强的抑制活性，对所有测试的革兰氏阳性菌属成员均有活性。该菌株在8至32摄氏度生长时产生一种热稳定的细菌素，但在45摄氏度时不产生。该细菌素被纯化至同质。通过电喷雾质谱法测定其质量为5250.11±0.30。细菌素的N端被封闭，无法通过埃德曼降解进行测序，但在通过溴化氰裂解肽后获得了42个氨基酸的部分序列。该序列与其他细菌素的序列没有相似性。嗜酸乳杆菌素L50似乎含有修饰氨基酸，但不含羊毛硫氨酸或甲基羊毛硫氨酸。
