# IGEM:IMPERIAL/2008/New/Growth Curve

(Difference between revisions)
 Revision as of 11:56, 11 September 2008 (view source)m ← Previous diff Revision as of 12:16, 11 September 2008 (view source)m (→The Model)Next diff → Line 28: Line 28: * Stationary phase: * Stationary phase: ** Occurs from 10s – 15 s.  Bacterial growth curve has ceased, hence the gradient of the growth curve does not change at this stage. ** Occurs from 10s – 15 s.  Bacterial growth curve has ceased, hence the gradient of the growth curve does not change at this stage. - - ** Explanation: ** Explanation: - ***      The assumption that the concentration of external nutrients is finite is included in this model ***      The assumption that the concentration of external nutrients is finite is included in this model - - *** Also, the behaviour of a bacteria consuming nutrients during its growth is incorporated in the model, hence the stationary phase *** Also, the behaviour of a bacteria consuming nutrients during its growth is incorporated in the model, hence the stationary phase - * For data analysis * For data analysis ** To characterise the chassis, we want to determine ** To characterise the chassis, we want to determine - + *** Time span of lag phase, stationary phase and exponential phase - *** time span of lag phase, stationary phase and exponential phase + *** The growth rate - + *** The error of each experiments - *** the growth rate + - + - *** the error of each experiments + ==Discussion== ==Discussion==

## Revision as of 12:16, 11 September 2008

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# Growth Curves

Authors: Erika and Prudence

Editors: Erika

## Why model the growth curve?

To characterise the B. subtilis chassis that we are using.

## How to model the growth curve?

In order to model the growth of B. subtilis, the process was broken down into three main steps where a submodel is produced in MATLAB in each step. Each submodel is an ODE model which can be simulated using MATLAB. The variables in each submodel are modified. So in the final step, a combination of submodel 1 and 2 are incorporated with submodel 3, resulting in a more complex model which illustrates the behaviour of bacterial growth. For more details about the process of building the model click on the following link: Tutorial for Growth curve.

## The Model

• The value of C determines the level at which the stationary phase (steady state) remain at.
• The lag phase:
• Occurs from 0 s to 5s: at 5 s growth curve begins to increase exponentially.
• Exponential phase:
• Occurs from 5s – 10s: growth increases exponentially and stops increasing at 10 s. The maximum growth is controlled by value of Cmax (found in M-file 1). At this same time period, the nutrient concentration decreases to zero, causing the bacterial growth to stop.
• Stationary phase:
• Occurs from 10s – 15 s. Bacterial growth curve has ceased, hence the gradient of the growth curve does not change at this stage.
• Explanation:
• The assumption that the concentration of external nutrients is finite is included in this model
• Also, the behaviour of a bacteria consuming nutrients during its growth is incorporated in the model, hence the stationary phase
• For data analysis
• To characterise the chassis, we want to determine
• Time span of lag phase, stationary phase and exponential phase
• The growth rate
• The error of each experiments

Growth Curve