Abstract: The lytic genes of phage λ with S amber mutation(S-RRz) were introduced into the recombinant E. coli VG1(pTU14) producing poly-β-hydroxybutyrate(PHB)to attain controllable lysis of cells. The results of EDTA/Tris(pH8.0)buffer treatment showed that S-RRz were successfully expressed in VG1(pTU14), and cell lysis was realized due to the action of EDTA on cytoplasm membrane.Here the function of EDTA was similar to that of S gene product.When PHB content was 85%—90％，membrane permeability would be increased by the abundantly accumulated in-cell PHB granules, and then the autolysis of recombinant cells occurred. After studies on different projects for direct separation of PHB from fermentation broth, a new technique, in which temperature treatment was introduced to simulate the function of S gene product, was presented, and the autolysis of cells was then easily realized based on the successful expression of S-RRz.By this simple technique, the final purity of PHB product could be up to 95%.

Key words: λ噬菌体裂解基因, 聚β-羟基丁酸酯, 细胞可控裂解

摘要： 将S基因琥珀突变的λ噬菌体裂解基因(S-RRz)引入产聚β-羟基丁酸酯（PHB）的重组大肠杆菌VG1(pTU14)中以实现细胞的可控裂解破壁.采用EDTA/Tris(pH值8.0)缓冲液处理结果表明，S-RRz在VG1(pTU14)中能够成功表达，且EDTA对细胞裂解的决定性作用是由于它模拟了S基因产物的功能.当细胞内PHB含量为85％～90％时，大量积累的PHB颗粒可以改变细胞膜的通透性，实现重组细胞的内控自裂解.对PHB与细胞进行直接分离的后处理工艺研究表明，在S-RRz成功表达的基础上，采用升温处理模拟S基因产物的功能诱导细胞自裂解，PHB产品纯度可以达到95％以上.

关键词: λ噬菌体裂解基因, 聚β-羟基丁酸酯, 细胞可控裂解