Answer:
5.0 x [tex]10^4[/tex] CFU/mL
Explanation:
The dilution factor for a 1:1,000 dilution is [tex]10^{-3}[/tex].
Since 1 mL of the dilution was taken, the dilution factor that yielded the colony is [tex]10^{-3}[/tex]/1 = [tex]10^{-3}[/tex]
In order to find the colony forming unit (CFU) per volume (1 mL) of the original culture, divide the number of colony resulting from the plating of 1 mL of the dilution by the dilution factor. Hence;
CFU/mL of the original culture = 50/[tex]10^{-3}[/tex]
= 5.0 x [tex]10^4[/tex]
Therefore, the concentration of the original culture is 5.0 x [tex]10^4[/tex] CFU/mL.
