Comparison of Primary Models to Predict Microbial Growth by the Plate Count and Absorbance Methods

Table 9

Growth parameters and their 95% confidence limits and coefficients of determination (), SSE, and RMSE of fit obtained with different growth models for average plate count growth curves of Escherichia coli CECT 4031 at 37°C in pH 5 TSB+YE inoculating 10², 10⁴, and 10⁶ CFU mL⁻¹ shown in Figure 3(c).

Growth model	Initial concentration (CFU mL^−1)	Lag time (h)	Growth rate; (log cycles h^−1)	(log CFU mL^−1)	(log cycles)			SSE	RMSE
Three-phase linear	10^2	1.61; (1.41–1.81)	0.518; (0.507–0.526)	2.011; (1.800–2.220)	—		0.992	0.3897	0.1731
	10^4	1.63; (1.39–1.89)	0.521; (0.508–0.544)	4.108; (3.790–4.430)	5.175		0.991	0.4079	0.1771
	10^6	1.74; (1.45–2.02)	0.574; (0.523–0.627)	6.052; (5.920–6.180)	3.229		0.948	0.9450	0.2931
Gompertz	10^2	1.49; (0.57–2.42)	0.576; (0.531–0.620)	1.687; (1.330–2.043)	7.489; (5.845–9.132)		0.997	0.1518	0.1125
	10^4	1.55; (0.97–2.13)	0.580; (0.549–0.611)	3.862; (3.641–4.083)	7.252; (6.270–8.234)		0.999	0.0669	0.0747
	10^6	2.25; (1.63–2.88)	0.692; (0.515–0.869)	6.180; (5.988–6.372)	3.233; (2.898–3.568)		0.985	0.3275	0.1652
Logistic	10^2	0.41; (−1.52–2.34)	0.578; (0.520–0.635)	1.011; (0.223–1.799)	7.501; (5.528–9.474)		0.995	0.2043	0.1305
	10^4	0.85; (−0.11–1.81)	0.593; (0.557–0.630)	3.344; (2.965–3.722)	6.952; (6.051–7.852)		0.998	0.0727	0.0778
	10^6	2.28; (1.64–2.93)	0.728; (0.576–0.880)	6.065; (5.866–6.265)	3.264; (2.987–3.541)		0.992	0.1763	0.1212
Richards	10^2	1.49; (−0.21–3.19)	0.002; (−3.220–3.224)	1.686; (0.453–2.919)	7.488; (4.798–10.180)	0.001; (−2.065–2.067)	0.996	0.1519	0.1175
	10^4	1.53; (0.45–2.60)	0.061; (−1.745–1.867)	3.839; (3.100–4.578)	7.214; (5.605–8.822)	0.041; (−1.248–1.330)	0.998	0.0671	0.0781
	10^6	2.11; (1.08–3.14)	0.953; (0.749–1.157)	5.573; (4.954–6.192)	3.691; (3.069–4.312)	7.363; (−3.876–18.600)	0.996	0.0874	0.0891
Baranyi	10^2	1.32; (0.71–1.92)	0.523; (0.489–0.556)	1.807	—		0.996		0.1176
	10^4	1.79; (1.45–1.92)	0.568; (0.539–0.598)	4.040	5.512		0.999		0.0624
	10^6	2.35; (1.76–2.93)	0.687; (0.528–0.849)	6.181	3.093		0.991		0.1288