Programmed Escherichia coli cell lysis by expression of cloned T4 phage lysis genes

Self-disruptive Escherichia coli that produces foreign target protein was d eveloped. E. coli was co-transformed with two vector plasmids, a target gen e expression vector and a lysis gene expression vector. The lytic protein w as produced after the expression of the target gene, resulting in simplific ation of the cell disruption process. In this study, the expression of clon ed T4 phage gene e or t was used for the disruption of E. coli that produce d beta -glucuronidase (GUS) as a model target protein. The expression of ge ne e did not lead to prompt cell disruption but weakened the cell wall. Res uspension with deionized water facilitated cell lysis, and GUS activity was observed in the resuspended liquid. Expression df gene e at mid logarithmi c growth phase was the optimal induction period for GUS production and rele ase. On the other hand, the expression of gene t induced immediate cell lys is, and intracellular GUS was released to the culture medium. Maximum GUS p roduction was obtained when gene t was induced at late logarithmic growth p hase.