IGEM:IMPERIAL/2008/New/Growth Curve
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[[Image:Log_graph.tif300pxLogGraph used to determine the growth rate]]}}  [[Image:Log_graph.tif300pxLogGraph used to determine the growth rate]]}}  
  {{Imperial/Box1  +  {{Imperial/Box1Key Phases of Bacterial Growth 
  +  ===Lag Phase===  
  +  During the lag phase, the rate of growth is slow due to two main reasons, ''B. subtilis'' is absorbing nutrients in the medium and the replication machinery is being switched on. The higher the concentration of nutrients in the medium, the faster the rate of bateria growth.  
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  +  As a result, the volume of the bacteria increases, followed by an increase in the number of bacteria.  
+  === Exponential Phase ===  
+  Both colony number and cell volume increase exponentially during this phase. Our model assumes concentration of the nutrients inside the bacteria is constant.  
  +  === Stationary Phase ===  
+  The growth of the colony ceases in number and in volume due to a finite concentration of nutrients, hence it 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}}  
  
  
  
{{Imperial/Box1The Model  {{Imperial/Box1The Model  
The model illustrates the main growth phases the ''B. subtilis'' undergoes. These are identified as the '''lag phase''', the '''exponential phase''' and the '''stationary phase'''. The death phase is a constitutive event and it is possible that it exerts an influence on the three phases discussed below. However, to simplify a complicated model, it is less relevant in this case and therefore is not included in this model.  The model illustrates the main growth phases the ''B. subtilis'' undergoes. These are identified as the '''lag phase''', the '''exponential phase''' and the '''stationary phase'''. The death phase is a constitutive event and it is possible that it exerts an influence on the three phases discussed below. However, to simplify a complicated model, it is less relevant in this case and therefore is not included in this model.  
  The Mfile used to generate the model below is located in the Appendices section  +  The Mfile used to generate the model below is located in the Appendices section of the Dry Lab hub. 
  [[Image:Nutrient ft.TIF500px  +  <center>[[Image:Nutrient ft.TIF500px]][[Image:Label_model.TIF500px]]</center>}} 
  [[Image:Label_model.TIF500px  +  
  
+  {{Imperial/Box1Results  
+  The 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 was also plotted as a function of time and is shown below. Based on our experimental results from the Wet Lab, a log graph was plotted to determine the growth rate. The growth rate was then determined from the gradient of the log graph. This value was included when simulating the growth model using MATLAB.  
+  <html><table border="0" cellpadding="5" cellspacing="0" align="center"><tr><td width=33%></html>[[Image:Experimental_Result.JPGthumbcenter]]<html>  
+  </td><td></html>[[Image:Fitted_Curve.JPGthumbcenter]]<html>  
+  </td><td></html>[[Image:Resource_Curve.JPGthumbcenter]]<html>  
+  </td></tr><tr><td><center>Experimental Results</center>  
+  </td><td><center>Fitted Curve</center>  
+  </td><td><center>Resource Curve</center>  
+  </td></tr></table></html>  
  +  The following constants used to generate the model were found to yield the best fit to experimental results.  
  +  GROWTH CONSTANT (A): 1.3494  
  +  INITIAL NUTRIENT CONCENTRATION (R<sub>0</sub>): 2  
  +  HILL COEFFICIENT (n): 1.25  
+  INITIAL OD: 0.4  
  +  CONSTANT (<math>\alpha</math>): 0.64516  
  +  }}  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
{{Imperial/EndPageDry_LabGenetic_Circuit}}  {{Imperial/EndPageDry_LabGenetic_Circuit}} 
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