Question

At 3:00 PM, you inoculate 1 x 103 cells in a closed flask on nutrient broth. The cells have a lag phase that lasts an hour. At 8:00 PM, the culture enters stationary phase. At that time, there are 6.5 x 107 cells in the flask. Calculate the number of generations (n), the number of generations/hour (k) and the doubling time or number of hours/generation (g).

Can anyone please help me with the following question. I don't want the answer in scientific notation. Please solve for

k=? And g=?. I already know n which is 15.88 which is correct.

Answer 1

Generation time (G) is the time (t) per generation. n = number of generations).

G=t/n

n = 3.3 logb/B

t = time interval in hours or minutes

B = number of bacteria at 4pm (1 hour is lag phase)

b = number of bacteria at the 8pm

n= 3.3 log (6.5*10⁷)- log (1*10³)= 3.3 (7.81-3)= 15.88

There is a lag phase of 1 hour, generation time is calculated only in log phase where the culture is actively growing.

G= t/n = (8-4)/n= 4/15.88= 0.251 hours per generation

Number of generations per hour (k)= 1/G= 1/0.251= 3.98 generations per hour