Fidelity (F) was obtained from the slope (S) of the log-linear phase of the growth curve via a best-fit fifth-order polynomial: F = 7.39 + 3.80 × S + 1.05 × S2 + 0.15 × S3 + 11.38 × 10-3 * S4 + 3.39 × 10-4 × S5.