Fermentation Reactors - Medical Science

Q1:

A fed-batch reactor containing 1 g.l-1 of substrate in 2 litre of medium. It is fed with 1 g.l-l of substrate at the rate of 1 litre per hour. After 10 hours, the concentration of substrate in the reactor was 0.5 g.l-1 . The mass of substrate that was used by the culture in the reactor was

A 2g

B 6g

C 8g

D 12g

ANS:B - 6g

Mass =volume * concentration.
The initial volume of the media is 10 litre.

After being fed for 10 hours at the rate of 1 litre per hour it is 12 litre.
Concentration is 0.5g/l.
Therefore mass is 12 * 0.5 = 6g.