Question

Recombinant insulin is produced at 100 mg/L by E. coli at a cell concentration of 1 g/L. Calculate the volume of reactor (size of the fermentor) needed to produce 1 Kilogram of insulin in the following conditions:

(a) When the cell concentration is 1 g/L and insulin production is 100 mg /L.

(b) When the cell concentration is 50 g/L and insulin production is 100 mg /L.

Answer 1

(a) Insulin production is 100 mg/L;

so fermentor volume needed for 1 Kg of insulin is 1 Kg / 100mg = 1000, 000mg/100,g = 10,000mg = 10,000L.

So we need 10,000-litre fermentor to produce 1 Kilogram of insulin in one batch.

(b) In this case the cell concentration is increased to 50 g/L;

so insulin production per liter will be 50 X 100 = 5000 mg = 5 g / L;

Thus, to produce 1 Kilogram of insulin we need 1 Kilogram / 5 g = 1000 g / 5g = 200 g.

So, if the cell concentration is increased 50 times, we need 200-litre reactor to produce 1 Kilogram of insulin.