TABLE 2.
Frequencies of mobilization of pBHR1 into different bacteriaa
| Recipient | Transfer frequencyb:
|
|
|---|---|---|
| Per donor | Per recipient | |
| Escherichia coli XA106F− | 3 × 10−2 | 1 × 10−1 |
| Ralstonia eutropha AE110 | 2 × 10−1 | 3 × 10−1 |
| Erwinia chrysanthemi A1240 | 1 × 10−2 | 1 × 10−1 |
| Klebsiella pneumoniae KAY2026 Nalr | 2 × 10−3 | 1 × 10−1 |
| Agrobacterium tumefaciens C58 Nalr | 3 × 10−2 | 2 × 10−2 |
| Salmonella enterica serovar Typhimurium MA767 Nalr | 2 × 10−2 | 1 × 10−2 |
| Pseudomonas stutzeri ATCC 17588 Nalr | 4 × 10−2 | 9 × 10−3 |
| Pseudomonas aeruginosa PAO362 Nalr | 9 × 10−3 | 7 × 10−3 |
| Azospirullum brasilense 7000 Nalr | 2 × 10−3 | 6 × 10−3 |
| Pseudomonas aeruginosa PAO531 | 8 × 10−3 | 4 × 10−3 |
| Serratia marcescens HY(y− Ψ−) Nalr | 2 × 10−3 | 1 × 10−3 |
| Erwinia herbicola RH6101 Nalr | 4 × 10−4 | 5 × 10−6 |
| Acinetobacter sp. strain AC58 Nalr | ≤2 × 10−6 | ≤9 × 10−7 |
| Proteus mirabilis NCTC5887 Nalr | ≤4 × 10−7 | ≤6 × 10−7 |
| Proteus vulgaris OX19 Nalr | ≤8 × 10−6 | ≤8 × 10−7 |
a
The Nals E. coli strain S17-1 containing an integrated RP4 plasmid and the Kanr pBHR1 plasmid was mated at 30°C on LB plates with various Nalr Kans bacteria as described by Lejeune et al. (26). After overnight incubation, the recipient, donor, and transconjugants were titrated at 30°C on LB medium supplemented with the appropriate antibiotics (nalidixic acid at 20 μg/ml; kanamycin at 50 or 1,000 μg/ml according to the recipient used).
b
Mobilization frequencies were determined by dividing the number of transconjugants (Kanr Nalr) by the number of recipients (Nalr) or donors (Kanr − Kanr Nalr).