TABLE 2.
Toxicity and β-exotoxin I concentrations in the culture supernatants of the various B. thuringiensis strain 407 varients
| Strain of B. thuringiensis | Insecticidal activity of culture supernatanta | β-Exotoxin I concn (μg/ml; T0 + 10 h) |
|---|---|---|
| 407(Cry+) | 80-100% mortality | 90 |
| 40(Cry−) | Nontoxic | 4.5 |
| 407-1(Cry−)(Pig+) | 80-100% mortality | 172 |
| 407-1(Cry−)(Pig+) berA::Tn10 | Nontoxic | 2 |
| 407-1(Cry−)(Pig+) ΔberAB::aphA3 | Nontoxic | 2.2 |
a
The 50% lethal dose of β-exotoxin I for the first-instar larvae of S. littoralis is 30 μg/ml.