QUESTION 1 The number of viable spores of a new strain of Bacillus subtilis is measured as a fun of time at various temperatures. Time Number of spores at: (min) T= 85°C T=90°C T= 110°C T= 120°C 0.0 2.40 x 109 2.40 × 10º 2.40 × 109 2.40 x 10 0.5 2.39 x 10° 2.38 x 10 1.08 x 10 2.05 x 10' 1.0 2.37 x 10 2.30 x 109 4.80 x 108 1.75 x 105 1.5 2.29 x 10' 2.20 X 108 1.30 x 10 2.0 2.33 x 10' 2.21 x 109 9.85 x 107 3.0 2.32 x 109 2.17 × 109 2.01 x 10' 4.0 6.0 00 2.28 x 109 2.12 x 109 4.41 x 10 2.20 x 109 1.95 × 10 1.62 x 105 8.0 2.19 x 109 1.87 x 10 9.0 6.88 x 10³ 2.16 x 10' 1.79 × 109 ii. iii. i. Determine the activation energy for thermal death of Bacillus subtilis spores [15 marks] ko What is the thermal death constant at 100°C? [3 marks] Estimate the time required to kill 99% of spores in a sample at 100°C? [2 mark Formula dN/dt = kN ==No e-kt =ko e-E/RT Wo/N) = ko te -E/RT