Answer:
The colony-forming unit includes the fungal or the bacterial cells and can be used for the cell counting. The colony forming unit is used for the viable cells.
The cfu/ ml can be calculated as follows:
cfu/ml=(no. of colonies × dilution factor)/volume of culture plate
In control:
We have given, the no. of colonies=160
, dilution factor=400 and volume=1ml
The cfu of the control is
cfu/ml(control)=(160 × 400)/1=64000 cfu/ml
For the experimental data,
We have given the no. of colonies=32
, dilution factor=200 and volume=0.1 ml
.
cfu/ml=32 × 200/0.1=64000 cfu/ml
.
Since, the cfu of the control and the experiment is equal, the preservative is of no use.