Comparison of the plasmid types obtained by two distantly related recipients in biparental exogenous plasmid isolations from soil

The effect of the recipient strain in exogenous plasmid isolations on the captured plasmid types was investigated by comparing HgR plasmids obtained from eight soils using Escherichia coli HB101RIF (γ-Proteobacteria) and Agrobacterium tumefaciens UBAPF2 (α-Proteobacteria). Plasmids isolated from 121 transconjugants were divided into 16 distinct types based on their restriction patterns and size. Only three of them were captured in both recipients, although nine more plasmid types could transfer and replicate in both E. coli HB101RIF and A. tumefaciens UBAPF2 in separate matings. The results indicate that using distantly related recipients in exogenous plasmid isolations allows capture of a wider spectrum of broad-host-range plasmids than if only one of them had been used.