The generation time of Escherichia coli (E. coli) in the laboratory under favorable conditions is 15-20 minutes.
In microbiology, generation time is defined as the doubling time of the microbial population from its initial number. In a closed environment, the pattern of growth in a cell population is sigmoid in nature and consists of four phases: lag, logarithmic (exponential), stationary, and death.
Under favorable conditions, in the laboratory, the bacterial population doubles at a particular time interval. The growth is in geometric progression or exponentially 20, 21, 22, 23………2n (where n = the number of generations) and the growth phase is called exponential growth phase. During this phase, all the cells in the population are dividing regularly by binary fission. This phase is also called the doubling phase.
The generation time of E. coli in the laboratory under favorable conditions (Glucose-salts medium) is 15-20 minutes.
The generation time of a microbe can be calculated as G = t/n, where
G = generation time
t = time interval
N1 = number of bacteria (beginning of a time interval)
N2= number of bacteria (end of the time interval)
n = number of generations
Number of generation (n)= 3.3 log N2/N1