Answer Happy

A chemostat of working volume 1000 mL is used to obtain steady-state data for metabolic flux analysis. Lactobacillus rhamnosus is cultured at pH 6.0 using sterile substrate medium containing 10 gl' of glucose. Lactic acid production is coupled with energy metabolism in this organism. Table 1 show the profile data of the fermentation at different glucose concentrations of different flow rate. Table 1: Fermentation profile of Lactobacillus rhamnosus in chemostat. L. rhamnosus Glucose Lactic acid Time Flow rate Concentration Concentration Concentration (h) (ml/h) (g/L) (g/L) (g/L). 300 0.5 10 3.3 2 280 0.63 6.19 5.1 3 220 0.926 4.38 6.9 5 168 1.09 3.047 8.7 7 140 1.33 1.106 10.5 9 120 1.43 0.466 12.8 11 110 1.43 0.285 13.1 15 48 1.23 0.078 16.4 ONMN a) By plotting the appropriate graphs, determine: i) the maximum specific growth rate, um (h"), ii) doubling time, ta (h), in) saturation constant, K (L'), iv) maximum biomass yield from glucose, yxs (g cell g glucose), v) maintenance coefficient, m. (g glucose g cells h") vi) endogenous cell loss rate constant, ko (h) Show how the values are obtained graphically. (42 marks)
b) Calculate the optimum dilution rate (Dop), optimum biomass concentration (Xopt) and productivity for cell production (Pry) if S. >>K, (6 marks) c) Determine the flowrate at the optimum dilution rate calculated in (b). (2 marks)