Table 2. Characterization of selected properties of exogenously isolated mercury resistance plasmids.

^aThe frequencies of conjugative transfers are given per recipient cell. Sinorhizobium meliloti strain FP2 served as the donor and S.meliloti strain L331, Pseudomonas sp. strain B131 and E.coli strain HBR101 served as recipients in the respective mating experiments. Transconjugants were selected on LB or TY medium containing 20 µg ml^–1 HgCl₂ and 100 µg ml^–1 rifampicin. The values given in parentheses indicate the limit of detection. n.d., not detected.