Abstract: | It has been shown that the plasmid R89S derivatives can be used as integrative vectors for bacteria in which the plasmid is unable to replicate autonomously. The chromosomal and plasmid fragments of phototrophic bacterium Rhodobacter sphaeroides have been cloned in plasmid pVZ365, a SmRKmR-derivative of R89S. The obtained recombinant plasmids were mobilized into R. sphaeroides cells by the I pcP-group conjugative plasmid R751. The frequencies of the SmR-transconjugants formation are 3.7.10(-5) to 5.6.10(-3) per recipient cell. The formation of the SmR-transconjugants has not been revealed in case of the plasmid pVZ365 mobilization. The recombinant molecules containing R. sphaeroides plasmid fragments have been shown to integrate into endogenous plasmids and form cointegrates with them. |