Takeya K, Shimamoto M, Mizuguchi Y
J Gen Microbiol. 1978 Dec;109(2):215-23. doi: 10.1099/00221287-109-2-215.
A mycobacteriocin (M12) produced by Mycobacterium smegmatic ATCC 25855 was partially purified by ammonium sulphate precipitation followed by DEAE-cellulose chromatography and Sephadex G100 chromatography. Production of M12 was maximal when bacteria were harvested after 3 d cultivation in liquid medium and disrupted by sonication. The molecular weight of M12, estimated by Sephadex G100 chromatograpy, was about 85000. M12 was sensitive to proteolytic enzymes but resistant to DNAase and RNAase, and was relatively stable to heat treatment, sonication, ultraviolet irradiation and pH over the range 4 to 8. When sensitive bacteria were exposed to the mycobacteriocin, the number of viable cells began to decrease after about 6 h incubation. The killing curve of M12 thus appeared to be a multiple-hit curve. Electron microscopic observation revealed that the mycobacteriocin induced morphological changes in the cells; these were partial loss of ribosomes, enlargement of lipoidal inclusion bodies and thickening of the cell envelope. The activity spectrum of M12 was restricted to the genus Mycobacterium.
耻垢分枝杆菌ATCC 25855产生的一种分枝杆菌素（M12），通过硫酸铵沉淀，随后进行DEAE-纤维素色谱和葡聚糖G100色谱进行部分纯化。当细菌在液体培养基中培养3天后收获并用超声处理破碎时，M12的产量最高。通过葡聚糖G100色谱估计，M12的分子量约为85000。M12对蛋白水解酶敏感，但对DNA酶和RNA酶有抗性，并且在4至8的pH范围内对热处理、超声处理、紫外线照射相对稳定。当敏感细菌暴露于分枝杆菌素时，在孵育约6小时后活细胞数量开始减少。因此，M12的杀伤曲线似乎是一条多击曲线。电子显微镜观察显示，分枝杆菌素诱导细胞形态发生变化；这些变化包括核糖体部分丧失、脂质包涵体增大和细胞膜增厚。M12的活性谱仅限于分枝杆菌属。
