Question

A 10-7 is performed on a culture of bacteria in order to perform viable plate counts. From the dilution, *0.1 mL* of solution is plated on solid media, and 66 colonies of bacteria grow on the plate. Assuming each colony came from a single bacterium, how many bacteria are in a single mL of the original culture?

Answer 1

`66 * 10^8` CFU/mL

Step-by-step explanation:

Given -

a) Number of colonies of bacteria is equal to
`66`

b) Total volume of the solution is equal to
`0.1` mL

c) Dilution factor is equal to
`10^(-7)`

As we know that

CFU/mL
`= (N * DF)/(V)`

Where N is the number of bacterial colonies, DF is the dilution factor and V is the volume

Substituting the given values in above equation, we get -

CFU/mL
`= (66* 10^7)/(0.1) \\= 66*10^8`