transfecting a bacterial cell comprising a lysogenic lambda prophage with a linear nucleic acid molecule, wherein the linear nucleic acid molecule comprises two homology arms that flank a plasmid origin of replication, wherein one of the homology arms is a homology arm of 30 to 1000 nucleotides in length that is homologous to a lambda nucleic acid sequence between a nucleic acid sequence encoding excisionase (xis) and a nucleic acid sequence encoding P_L and another of the homology arms is a homology arm of 30 to 1000 nucleotides in length that is homologous to a lambda nucleic acid sequence encoding a c1857 repressor, P_R and/or Cro; and

inducing expression of Beta from the lysogenic lambda prophage;

thereby inducing recombination of the linear nucleic acid molecule with the lambda prophage and producing a plasmid comprising the plasmid origin of replication and a lambda prophage nucleic acid sequence,

wherein the lysogenic lambda prophage comprises P_L; the nucleic acid sequence encoding Beta operably linked to P_L; a nucleic acid sequence encoding P; a nucleic acid sequence encoding O; a nucleic acid sequence encoding Cro; a nucleic acid sequence encoding integrase (int), a nucleic acid encoding xis, and att;

a phage origin of replication, and

a nucleic acid sequence encoding c1857 repressor;

and the lambda nucleic acid sequence located between the nucleic acid sequence encoding xis and the nucleic acid sequence encoding Beta and the lambda nucleic acid sequence encoding the c1857 repressor, P_R and Cro;

wherein the nucleic acid sequence encoding Cro comprises an amber codon, the nucleic acid sequence encoding P, the nucleic acid sequence encoding O, or both the nucleic acid sequence encoding P and the nucleic acid sequence encoding O comprise an amber codon, such that Cro and P, Cro and O, or Cro, P and O are not produced when the lambda phage is introduced into a suppressor minus host cell;

wherein the lambda prophage does not comprise an active bacterial origin of replication; and wherein the lambda prophage is lysogenic in a suppressor minus host cell and is lytic and produces phage at 42° C. in a host cell that produces an amber suppressive tRNA.

replacing the plasmid origin of replication with a different origin of replication.

transfecting a bacterial cell comprising a lysogenic lambda prophage with a linear nucleic acid molecule,

wherein the lysogenic lambda prophage comprises a nucleic acid sequence encoding Beta operably linked to P_L; a nucleic acid sequence encoding c1857; a nucleic acid sequence encoding P; a nucleic acid sequence encoding O; and a nucleic acid sequence encoding Cro;

wherein the linear nucleic acid molecule comprises first and second homology arms that flank a plasmid origin of replication, wherein each of the first and second homology arms is a homology arm of 30 to 1000 nucleotides in length that is homologous to the lysongenic prophage;

wherein the lambda prophage does not comprise an active bacterial origin of replication; and

wherein the lambda prophage is lysogenic in a suppressor minus host cell and is lytic and produces phage at 42° C. in a host cell that produces an amber suppressive tRNA; and

inducing expression of Beta from the lysogenic lambda prophage in the bacterial cell, thereby inducing recombination of the linear nucleic acid molecule with the lambda prophage and producing a plasmid comprising the plasmid origin of replication and a lambda prophage nucleic acid sequence, wherein the lambda prophage nucleic acid sequence comprises the nucleic acid sequence encoding Beta.