Team:Shanghai Metro/Model
MODEL
In order to determine the appropriate tetracycline induction concentration range
for better growth of our
patent strains, we tested the OD600 of the strains under various concentration of tetracycline
and collected
the data against hours and built the model.
Below is the initial data:
Table 1. OD600 value of the strain D: Pus232-ike4-tke4 after 6 hours
According to the scatter-plot analysis by MATLAB, the data points have a tendency
of oscillation decline,
and there is no model of elementary function conforming to this trend. Therefore, we decided to use
interpolation method to study the numerical transformation and obtained the final curve.
Interpolation method selection: although the curve obtained by spline interpolation
(Spline) is the most smooth, it will produce negative values, which does not conform to the actual
situation. Therefore, Hermite interpolation method (Pchip) is chosen to keep the shape of the original data.
As the curve above, the X-coordinate shows the concentration of tetracycline and
the Y-coordinate shows the corresponding OD600 value of the strain D. In order to find the
appropriate range
of the tetracycline concentration, we referred the OD600 value of the blank control strain after
6 hours
without tetracycline:
Table 2. OD600 value of the strain E: Pus232 after 6 hours
Therefore we drew a horizontal line where OD600 equals 0.3268 and find
the cross
points of these two lines where Xs are 17, 26, 78 and 113. As seen from the graph, it indicates that the
growth of our patent strain (strain D) could grow normally even better the normal strain (strain E) when we
add the tetracycline within the range from 17 µg/L to 26 µg/L, or the more recommended 78 µg/L to
113µg/L.Regarding the range from 0 to 17 µg/L where we didn't have samples to verify the accuracy, thus we
didn’t count it as the recommended concentration range.
To sum up, this model and this recommended concentration range could be used for the future application of
our patented-strain protection technology.