Question

If escheria coli has a generation time of 20 minutes, will you be able to construct a growth curve from the following data ? Initial time 0 absorbance 0.05 cell number per every mL 1.0x10⁷ . Ending Time 20 minutes absorbance 0.07 cell number 1.0x10^{7 ?}

Answer 1

No. We need more time and number of generations to construct a growth curve.

Here the generation time of E coli is 20 minutes. Initial time 0 absorbance 0.05 cell number per every mL 1.0x10⁷ and ending time 20 minutes wtih absorbance 0.07 cell number 1.0x10⁷ . In this generation time, E coli is still in lag phase of its growth.

Here the number of cells have not even increased. The time provided, 20 minutes, is barely enough for formation of a single generation. If you need a proper growth curve, you should provide more time for the bacteria to grow and multiply. Below is a typical bacterial growth curve.

And for a typical E coli sample, we have

If you look at the graph, the bacterial is in lag phase for at least the first hour of the growth time. Hence the given data is not sufficient to construct a growth curve.