Yildirim Z, Johnson M G
Department of Food Science and Arkansas Biotechnology Center, University of Arkansas, Fayetteville 72704, USA.
J Food Prot. 1998 Jan;61(1):47-51. doi: 10.4315/0362-028x-61.1.47.
Five stains of Bifidobacterium bifidum (ATCC 11863 and 29591, and NCFB 1453, 1454, 1455) were examined for production of bacteriocins in MRS broth with 0.05% cysteine. Only strain NCFB 1454 excreted a bacteriocin into the broth: it was designated bifidocin B. Bifidocin B was sensitive to several proteolytic enzymes (protease IV, pronase E, protease XVII, proteinase K, trypsin, alpha-chymotrypsin, papain, and pepsin), but was resistant to catalase, peroxidase, lipase, lysozyme, cellulase, ribonuclease A, and amylases. It was also resistant to organic solvents such as ethyl alcohol, acetone, hexane, chloroform, methanol, and ether, and to heating at 90 degrees C for 15, 30, and 60 min or at 121 degrees C for 15 min. Bifidocin B remained active after storage at -20 or -7 degrees C for 3 months and retained biological activity after exposure to pH values of 2 to 10. Bifidocin B was active against some food-borne pathogens and food spoilage bacteria such as Listeria, Enterococcus, Bacillus, Lactobacillus, Leuconostoc, and Pediococcus species but was not active against the other gram-positive and gram-negative bacteria tested. Bifidocin B was produced during exponential phase, reaching a maximum activity of 3,200 AU/ml at early stationary phase. Bifidocin B had a molecular mass of about 3.3 kDa as analyzed by Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
对五株两歧双歧杆菌（ATCC 11863、29591以及NCFB 1453、1454、1455）在添加0.05%半胱氨酸的MRS肉汤中进行细菌素产生情况检测。只有NCFB 1454菌株向肉汤中分泌了一种细菌素：将其命名为双歧菌素B。双歧菌素B对几种蛋白水解酶（蛋白酶IV、链霉蛋白酶E、蛋白酶XVII、蛋白酶K、胰蛋白酶、α-胰凝乳蛋白酶、木瓜蛋白酶和胃蛋白酶）敏感，但对过氧化氢酶、过氧化物酶、脂肪酶、溶菌酶、纤维素酶、核糖核酸酶A和淀粉酶具有抗性。它对有机溶剂如乙醇、丙酮、己烷、氯仿、甲醇和乙醚也具有抗性，并且在90℃加热15、30和60分钟或在121℃加热15分钟后仍具有抗性。双歧菌素B在-20℃或-7℃储存3个月后仍保持活性，在pH值为2至10的环境下暴露后仍保留生物活性。双歧菌素B对一些食源性病原体和食品腐败细菌如李斯特菌属、肠球菌属、芽孢杆菌属、乳杆菌属、明串珠菌属和片球菌属具有活性，但对所测试的其他革兰氏阳性和革兰氏阴性细菌没有活性。双歧菌素B在指数生长期产生，在稳定期早期达到最大活性3200 AU/ml。通过Tricine-十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析，双歧菌素B的分子量约为3.3 kDa。
