A predictive model of Vibrio cholerae for combined temperature and organic nutrient in aquatic environments

Aims To develop a predictive model for Vibrio cholerae in sea water. Methods and Results The growth curves of V. cholerae NE-9 at different temperatures (range from 10 to 30 degrees C) and chemical oxygen demand (COD) concentration (range from 5 to 40 mg l-1) were determined. The modified logistic model and Baranyi model were chosen to regress the growth curves. A new method for modelling effects of temperature and COD on the specific growth rate (mu) was successfully developed by a combination of modified square roottype equation and saturation growth rate model. The coefficient of determination (R2), bias factor (Bf) and accuracy factor (Af) were taken to assess the performance of the established model. Logistic model produced a good fit to the observed data (R2 = 0.952). However, the Baranyi model provided biologically plausible parameter estimates. The overall predictions for V. cholerae NE-9 growth agreed well with observed plate counts, and the average R2, Bf and Af values were 0.967, 1.198 and 1.201, respectively. Conclusion The predicted model agreed well with observed data, and the result can be applied for the prediction of V. cholerae in actual environments. Significance and Impact of the Study The results of this study provide the basis for the prediction of V. cholerae in sea water.