Figure 4

Correlation between hardness (Young’s modulus) and indirect measurements of heat and UV resistance. (A) Young’s modulus vs. D₁₂₁ values. (B) Young’s modulus vs. irradiation energy. Key for both panels: □, Geobacillus stearothermophilus; Δ, Bacillus coagulans; ○, Bacillus subtilis; ▴, Bacillus licheniformis; ●, Bacillus megaterium.