INVESTIGATION OF A PHAGE RESISTANT SERRATIA-ENTOMOPHILA STRAIN (BC4B), ESTABLISHMENT OF GENERALIZED TRANSDUCTION AND CONSTRUCTION OF SERRATIA-ENTOMOPHILA RECA MUTANTS

A recA clone was isolated from a cosmid library of Serratia entomophil a constructed in the Escherichia coli strain HB101. Subcloning and tra nsposon mutagenesis were used to identify a 1.36 kb fragment containin g the recA gene. A cloned recA mutation, generated by transposon mutag enesis and the replacement of a portion of the recA gene with an antib iotic resistance cassette, was introduced into the chromosome via a ma rker exchange technique. The recA strains created were deficient in DN A repair, homologous recombination and both the spontaneous and UV ind uction of prophages. S. entomophila recA strains showed continued path ogenicity towards the New Zealand grass grub, Costelytra zealandica. S imple procedures for further construction of S. entomophila recA strai ns have been demonstrated.