Figure 4.

Growth and enterotoxin production of the B. thuringiensis strains. (A) Growth under simulated intestinal conditions (RPMI 1640 medium treated with CaCo-2 cells, 37 °C, 7% CO₂). (B) NheB production after six hours growth under simulated intestinal conditions (cRPMI, red). Reciprocal NheB titres after six hours growth in CGY medium (nutrient-rich, aerobic conditions) are shown for comparison (orange). (C) Hbl L2 production after six hours growth under simulated intestinal conditions (cRPMI, dark blue). Reciprocal Hbl L2 titres after six hours growth in CGY medium (nutrient-rich, aerobic conditions) are shown for comparison (light blue). *: Significant difference compared to the isolate with highest toxin production (p-value ≤ 0.05; unpaired t-test, 95% confidence interval). Blue: animal isolate, green: food, red: biopesticide, brown: soil, black: unknown origin.