Question

While making a bowl of pasta salad for a birthday party, 20 bacterial cells are introduced into the dish.

- 3 hours before the birthday party, the pasta salad sits in room temperature in a kitchen. Assuming the generation time is 30 minuets, how many bacterial cells are now present ?

- Elaborate how contamination of the pasta salad could have been reduced or prevented ?

Answer 1

A) - As bacterial cells divides by binary fission hence one bacteria give rise to two daughter cells.

One bacteria divide in= 30 minutes

Total time for division of bacteria =3 hour =180 minutes

No of divisions = 180/30= 6divisions.

Hence no of bacteria will be=1280 bacteria.

(Calculate by multiplying 2 with 20 six times).

B)- the contamination of pasta can be prevented by putting the pasta at high temperature or at low temperature such as in the fridge or in the oven as the division of bacteria stops at these temp. You can also use filter papers with pore size smaller then bacterial size to cover the pasta so that the bacterial do not get into the pasta.