Construction of various bacteriophage λ mutants for stable and efficient production of recombinant protein in Escherichia coli

Three λ mutants were constructed based on the Q− mutant in order to enhance their productivity and stability in an Escherichia coli/bacteriophage λ system. The newly constructed bacteriophage mutants named λSNU1, λSNU2, and λSNU3 were Q−S−, Q−W−E−, and Q−S−W−E− mutants, respectively. Compared to all of the mutants, λSNU1 turned out to be the best with regards to higher protein expression and better genetic stability. Mechanisms by which these attributes are achieved have been discussed. The high productivity of P90c/λSNU1 for the recombinant protein was due to the high copy number of λ DNA and high translational efficiency. This mutant phage λSNU1 can be used to provide a high level of stability and productivity of the cloned gene particularly for long-term continuous operation.