Favret M E, Yousten A A
J Invertebr Pathol. 1989 Mar;53(2):206-16. doi: 10.1016/0022-2011(89)90009-8.
Bacillus thuringiensis serovar, thuringiensis (HD-2) demonstrated antibacterial activity against 48 of 56 strains of B. thuringiensis and against some other Gram-positive species but not against Gram-negative species. The antibacterial activity was not inducible by mitomycin C or by ultraviolet irradiation, and additional activity was not liberated from cells by sonication. Upon dilution of the antibacterial substance, zones of inhibition diminished without the appearance of plaques. Gel filtration chromatography indicated an Mr greater than 950,000 for the bacteriocin (thuricin) in its native form. The native thuricin was sedimented by ultracentrifugation, but electron microscopy of the pellet failed to reveal phage particles or phage components. Nondenaturing polyacrylamide gel electrophoresis (PAGE) of thuricin demonstrated the association of bacteriocin activity with a protein band which migrated only slightly into a 5% gel. Sodium dodecyl sulfate (SDS)-PAGE of partially purified thuricin revealed five major bands. Thuricin activity was substantially reduced by treatment with chymotrypsin, pronase, subtilisin, trypsin, and heat at 96 degrees C but not by treatment with lysozyme, phospholipase C, papain, peptidase, or organic solvents. It exhibited a bactericidal and bacteriolytic effect on a sensitive strain, B. thuringiensis serovar, canadensis (MF4). Partially purified preparations of thuricin had phospholipase A activity which was adsorbed by sensitive cells but not by cells which were insensitive to thuricin. Antibacterial activity was blocked by preincubation of thuricin with phospholipid. Loss of a 150-mDa plasmid was correlated with loss of thuricin production.
苏云金芽孢杆菌苏云金亚种（HD - 2）对56株苏云金芽孢杆菌中的48株以及一些其他革兰氏阳性菌具有抗菌活性，但对革兰氏阴性菌无活性。其抗菌活性不能被丝裂霉素C或紫外线诱导，超声处理也不会使细胞释放出额外的活性。抗菌物质稀释后，抑菌圈缩小但未出现噬菌斑。凝胶过滤色谱表明，其天然形式的细菌素（苏云金素）的相对分子质量大于950,000。天然苏云金素可通过超速离心沉淀，但对沉淀的电子显微镜观察未发现噬菌体颗粒或噬菌体成分。苏云金素的非变性聚丙烯酰胺凝胶电泳（PAGE）显示，细菌素活性与一条仅轻微迁移到5%凝胶中的蛋白带相关。部分纯化的苏云金素的十二烷基硫酸钠（SDS）-PAGE显示有五条主要条带。用胰凝乳蛋白酶、链霉蛋白酶、枯草杆菌蛋白酶、胰蛋白酶处理以及96℃加热后，苏云金素的活性大幅降低，但用溶菌酶、磷脂酶C、木瓜蛋白酶、肽酶或有机溶剂处理则不会。它对敏感菌株苏云金芽孢杆菌加拿大亚种（MF4）表现出杀菌和溶菌作用。部分纯化的苏云金素制剂具有磷脂酶A活性，该活性可被敏感细胞吸附，但不能被对苏云金素不敏感的细胞吸附。苏云金素与磷脂预孵育会阻断其抗菌活性。150 - mDa质粒的丢失与苏云金素产生的丧失相关。
