# IGEM:IMPERIAL/2008/New/Growth Curve

### From OpenWetWare

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[[Image:Label_model.TIF]] | [[Image:Label_model.TIF]] | ||

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- | + | ==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. | 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 increases in the number of bacteria. | As a result, the volume of the bacteria increases, followed by an increases 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. | 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 its does not have a gradient. Other causes may be death and cell division. | The 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. |

## Revision as of 13:37, 27 September 2008

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{{Imperial/Box1|| ## 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 was also plotted as a function of time and is shown below. From experimental 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_0 = 2 HILL COEFFICIENT: n = 1.25 INITIAL OD = 0.4 CONSTANT: α = 0.64516
## DiscussionGrowth Curve |