Paik H D, Bae S S, Park S H, Pan J G
Bioprocess Engineering Division, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Taejon, Korea.
J Ind Microbiol Biotechnol. 1997 Oct;19(4):294-8. doi: 10.1038/sj.jim.2900462.
Bacillus thuringiensis subsp tochigiensis HD868 was identified as a bacteriocin producer which exhibited a bactericidal effect against closely related species. This bacteriocin designated as tochicin, was partially purified by 75% ammonium sulfate precipitation followed by subsequent dialysis. This partially purified tochicin showed a narrow antibacterial spectrum of activity against most of 20 typical B. thuringiensis strains and a strain of B. cereus, but not against other bacteria and yeasts tested. The antibacterial activity of tochicin on sensitive indicator cells disappeared completely by proteinase K treatment (1 mg ml-1), which indicates its proteinaceous nature. Tochicin was very stable throughout the range of pH 3.0-9.0 and was relatively heat-stable at 90 degrees C, but bacteriocin activity was not detected after boiling for 30 min. The relationship between cell growth and bacteriocin production was studied in a semi-defined medium. Tochicin activity was detected at the mid-log growth phase, reached the maximum at the early stationary phase, but decreased after the stationary phase. Direct detection of tochicin activity on sodium dodecyl sulfate-polyacrylamide gel suggested it has an apparent molecular mass of about 10.5 kDa. Tochicin exhibited a bactericidal activity against B. thuringiensis subsp thompsoni HD522 in phosphate buffer (pH 7.0).
苏云金芽孢杆菌枥木亚种HD868被鉴定为一种细菌素产生菌，对密切相关的物种具有杀菌作用。这种细菌素被命名为枥木菌素，通过75%硫酸铵沉淀随后进行透析进行部分纯化。这种部分纯化的枥木菌素对20株典型苏云金芽孢杆菌菌株中的大多数以及一株蜡样芽孢杆菌显示出较窄的抗菌活性谱，但对测试的其他细菌和酵母没有作用。枥木菌素对敏感指示细胞的抗菌活性通过蛋白酶K处理（1毫克/毫升）完全消失，这表明其蛋白质性质。枥木菌素在pH 3.0 - 9.0范围内非常稳定，在90℃相对耐热，但煮沸30分钟后未检测到细菌素活性。在半限定培养基中研究了细胞生长与细菌素产生之间的关系。枥木菌素活性在对数生长中期被检测到，在稳定期早期达到最大值，但在稳定期后下降。在十二烷基硫酸钠 - 聚丙烯酰胺凝胶上直接检测枥木菌素活性表明其表观分子量约为10.5 kDa。枥木菌素在磷酸盐缓冲液（pH 7.0）中对苏云金芽孢杆菌汤普生亚种HD522表现出杀菌活性。
