Research Article

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

Table 4

Growth parameters obtained and their 95% confidence limits and coefficients of determination (), SSE, and RMSE of fit with different growth models for the average OD growth curves of Escherichia coli CECT 515 at 37°C in pH 5 TSB+YE inoculating 102, 104, and 106 CFU mL−1 shown in Figure 1(c).

Growth modelInitial concentration (CFU mL−1)Lag time (h)Growth rate
(OD units h−1)

(OD units)

(OD units)
SSERMSE

Three-phase linear10214.80
(14.60–15.00)
0.103
(0.100–0.105)
0.161
(0.115–0.207)
1.6220.9950.02000.0250
1049.70
(9.53–9.86)
0.110
(0.107–0.112)
0.167
(0.111–0.223)
1.6560.9960.01500.0220
1064.44
(4.27–4.61)
0.111
(0.108–0.113)
0.176
(0.113–0.239)
1.6000.9960.01500.0224

Gompertz10215.46
(15.29–15.62)
0.117
(0.115–0.119)
0.144
(0.137–0.152)
1.794
(1.780–1.807)
0.9990.07000.0227
10410.29
(10.13–10.46)
0.125
(0.123–0.128)
0.146
(0.137–0.155)
1.799
(1.785–1.812)
0.9990.06630.0227
1064.65
(4.42–4.89)
0.125
(0.122–0.127)
0.123
(0.106–0.140)
1.783
(1.761–1.805)
0.9990.05970.0237

Logistic10215.51
(15.12–15.90)
0.117
(0.113–0.121)
0.105
(0.088–0.121)
1.784
(1.758–1.810)
0.9970.25440.0433
1049.95
(9.56–10.33)
0.123
(0.119–0.126)
0.078
(0.057–0.094)
1.834
(1.808–1.860)
0.9970.18250.0376
1063.67
(3.46–3.89)
0.120
(0.117–0.123)
0.000a1.875
(1.864–1.887)
0.9970.12320.0339

Richards10215.46
(15.18–15.73)
0.00008
(−0.016–0.016)
0.144
(0.137–0.152)
1.794
(1.772–1.816)
0.00024
(−0.049–0.049)
0.9990.06700.0228
10410.29
(9.98–10.61)
0.0001
(−0.063–0.063)
0.146
(0.135–0.156)
1.799
(1.778–1.819)
0.00041
(−0.185–0.186)
0.9990.06630.0228
1064.65
(4.41–4.90)
0.0002
(−0.107–0.107)
0.123
(0.086–0.159)
1.783
(1.743–1.824)
0.00062
(−0.316–0.317)
0.9990.05980.0239

Baranyi10214.31
(13.87–14.75)
0.101
(0.097–0.105)
0.1261.742
(1.727–1.756)
0.9960.0445
1048.96
(8.50–9.41)
0.107
(0.103–0.111)
0.1151.777
(1.763–1.789)
0.9960.0445
1062.72
(2.07–3.38)
0.104
(0.099–0.109)
0.0601.791
(1.776–1.806)
0.9940.0483

Value fixed at bound.