Chapter 4, Problem 4.63P

A genetically engineered strain of Escherichia coli (E. coli) is used to synthesize human insulin for people suffering from type I diabetes mellitus. In the following simplified reaction scheme, bacteria consume all of the limiting reactant under aerobic conditions and produce insulin and biomass.

C₆H₁₂O₆ + oNH₃+ bO₂

/7C2.3H2 gO₍ iiN(insulin) + 2 + 5H2O

Feed containing 150 mM glucose (that is, 150 x 10-3 mol C₆H|₂O6/L) and 50 mM ammonia enters a bioreactor at a rate of 100 L/h. Pure oxygen enters the reactor as a gas at the same molar How rate as the ammonia. The product stream leaves at a rate of 100 L/h. The respiratory quotient (see Problem 4.62) RQ = 0.50 mol CO₂ produced/mol O₂ consumed, and the molar ratio of biomass to insulin produced in the reaction is 1.5. The system operates at steady state.

1. Determine the six stoichiometric coefficients and the limiting reactant.

What are the fractional conversion of glucose and the production rates (g/h) of insulin and biomass?