[Mu-induced deletions and mutations of Erwinia carotovora chromosomes, including resident prophages E105 and 59].

The plasmid RP4::Mu cts62 in stably inherited by Erwinia carotovora 268 strain. Under the conditions of thermoinduction bacteriophage Mu is segregated and completely eliminated more intensively than in Escherichia coli cells. At thermoinduction the transposition of bacteriophage Mu cts62 into different chromosomal sites takes place, causing the induction of chlorate resistant and auxotrophic mutants with the frequency of 10(-4). Two clones deficient in production of 2 of the 4 resident prophages of Erwinia carotovora 268 strain were found among Mu-induced mutants. The deleted prophages are E105 and 59. DNA-DNA hybridization has revealed the complete and partial deletions of bacteriophage E105 with the level of L-asparaginase production in the cells remaining intact. The damage of the prophage 59 is probably caused by point mutations or short deletions.