# IGEM:IMPERIAL/2008/New/Growth Curve

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## Growth Curves## Why model the growth curve?The aim of modelling the growth curve is to characterise the ## How to model the growth curve?In order to model the growth of In the final step, a combination of Submodels 1 and 2 are superposed with Submodel 3, resulting in a more complex model which enhances the accuracy of illustrating bacterial growth. For more details about the submodels, please click on the following link: Media:Modelling_Growth_Curve.pdf. For more information on our modelling strategy, please click on Tutorial for Growth Curve. ## The ModelThe M-file used to generate the model below is located in the Appendices section, its link can be found at the bottom of this page. The model illustrates the main growth phases the ## LAG PHASEDuring the lag phase, the rate of growth is slow due to two main reasons, As a result, the volume of the bacteria increases, followed by an increases in the number of bacteria. ## EXPONENTIAL PHASEBoth colony number and cell volume increase exponentially during this phase. Our model assumes concentration of the nutrients inside the bacteria is constant. ## STATIONARY PHASEThe growth of the colony ceases in number and in volume due to a finite concentration of nutrients, hence its does not have a gradient. Other causes may be death and cell division. According to the model, the maximum growth of the bacteria is determined by the concentration of nutrients available initially. To further enhance the accuracy of the model, the following information will be extracted from experimental data: - Time span of lag phase, stationary phase and exponential phase
- The growth rate
## ResultsThe model for the growth curve was fitted to the experimental results as shown below. The experimental results is depicted by the red curve, while our model is shown by the green curve. The resource curve also indicates that there is a period of time for which nutrients is being transported into the cells, contributing to the lag phase of the growth curve. From experimental
GROWTH CONSTANT: A = 1.3494 INITIAL NUTRIENT CONCENTRATION: R_0 = 2 HILL COEFFICIENT: n = 1.25 INITIAL OD = 0.4 CONSTANT: α = 0.64516
## DiscussionGrowth Curve |