Strains | Conjugants/viable cells | Conjugants/ml |
---|
P. inhibens
| 1.0 × 10-6 | 1.0 × 105 |
P. gallaeciensis
| 2.0 × 10-4 | 3.0 × 103 |
O. indolifex
| 2.7 × 10-2 | 5.0 × 105 |
R. litoralis
| 5.0 × 10-4 | 1.0 × 103 |
R. denitrificans
| 2.0 × 10-4 | 2.0 × 103 |
D. shibae
| 2.4 × 10-2 | 2.0 × 106 |
- aThe recipient Roseobacter strains were cultivated for 18 h in MB at 30°C and the donor E. coli ST18 was grown up to the logarithmic phase (OD578 = 0.5-0.6) in LB supplemented with 50 μg/ml ALA at 37°C. Mating mixtures were incubated on hMB supplemented with 50 μg/ml ALA over 24 h at 30°C in a donor:recipient ratio 10:1. Afterwards, the cells were resuspended in 1 ml MB, diluted serially in 1.7% (w/v) sea salt solution and plated on hMB with and without antibiotics, respectively, to determine the number of conjugants and viable cells. A donor:recipient ratio of 5:1 revealed the same results. The results represent the mean of three independent experiments performed in duplicate.