Characterization of a methionine sulfoximine resistant strain of Rhodobacter capsulatus E1F1

The transposon-loaded plasmid pAS8-121, incapable of autonomous replication in Gram-negative bacteria of non-enteric group, was transferred to Methylobacillus flagellatum KT wild type strain MFK1. The transconjugants arose at a frequency of 10(-7) per donor cell. The majority of the transconjugants tested exhibited the transfer of all selected chromosomal markers at rather high (10(-4)-10(-6) per donor cell) but similar frequencies. Only one of the obtained donors, designated MFK 64, was capable of mobilizing M. flagellatum KT chromosome in a polarized manner. The integrated nature of the plasmid in this and other MFK1 (pAS8-121) derivatives was supported by the results of DNA-DNA hybridization.