TABLE 1.
Larvicidal activity of B. sphaericus recombinant strains against C. pipiens subsp. pipiens larvae
| B. sphaericus strain | Suspension (all sonicated)a | Larvicidal activityb
|
|
|---|---|---|---|
| LC50c | LC90 | ||
| 2297 (parental) | Spore pelletd | 2.1 ± 0.4 | 12.6 ± 8.8 |
| Purified inclusion bodies | 8 ± 0.05 | 15.5 ± 1.3 | |
| 2297(pMK3) | Washed FWC | 31 ± 2.5 | 59.7 ± 7.3 |
| 2297(pcyt1Ab1) | Washed FWC | 73.3 ± 17.3 | 181.3 ± 75.3 |
| Spore pellet | 7.1 ± 0.9 | 18.6 ± 2.8 | |
| Purified inclusion bodies | 72.4 ± 4.8 | 306 ± 222 | |
| 2362 | Washed FWC | 15.9 ± 1.9 | 28.6 ± 4.4 |
| 2362(pcyt1Ab1) | Washed FWC | 28.5 ± 4.5 | 64.5 ± 0.4 |
| Iab872(pcyt1Ab1) | Washed FWC | 27.9e | 194 |
| Iab872(pcyt1Ab1) | Spore pellet | 5.8 ± 3.5 | 27.4 ± 19 |
| Iab872(pMK3) | Spore pellet | 2.6e | 7.1 |
| 2297 asporulated(pMK3) | Washed FWC | 95.8 ± 45 μg/ml | 526.9 ± 299 μg/ml |
| 2297 asporulated(pcyt1Ab1) | Washed FWC | 109 ± 29.4 μg/ml | 360.0 ± 180 μg/ml |
| B. thuringiensis SPL 407(pcyt1Ab1) | Purified crystals | 5.7 ± 3.1 μg/ml | 29.7 ± 17.3 μg/ml |
a
All B. sphaericus suspensions were subjected to sonication two times for 10 min each before the experiments.
b
Unless otherwise noted, values are in nanograms per milliliter.
c
Lethal concentrations after 48 h of larval exposure.
d
Spores pelleted after ultracentrifugation.
e
The result of one experiment.