10. Understanding Monod's equation Part -2 | Bioprocess Technology | Notes and MCQ's in description.

!! A MISTAKE IN VIDEO !! Correct formula is S = KsD/Umax - D Question's 1. The volume of a continuous stirred tank bioreactor is 1000 liters. The feed flow rate to the reactor is 200liters/hr. And the glucose concentration in the feed is 5g/l. Determine the steady-state substrate concentration. Use the following cell constants:- umax = 0.3 per hr, Ks = 0.3g/l. 2. The maximum specific growth rate is 0.5 per hr and the steady-state substrate concentration is 0.8g/l. Calculate the feed flow rate if the volume of the bioreactor is 500 liters (Ks = 0.1g/l). 3. Calculate the dilution rate if the steady-state substrate concentration is 0.9g/l and the specific growth rate under is 0.3 per hr. Use Ks = 0.23g/l. 4. The unit of dilution rate is a. Litre/hr b. Litre/min c. per hr d. per litre Answers 1) 0.6g/L 2) 222.22L/hr 3) 0.3/hr 4) c Notes - In a continuous stirred tank reactor the reaction mixture is entirely homogenous due to the stirring action of impellers and agitators. Under steady-state conditions 1. The inflow rate is equal to the outflow rate so that the volume of broth inside the bioreactor remains constant 2. Cell concentration inside the bioreactor remains constant = steady-state cell concentration 3. Substrate concentration inside the bioreactor remains constant = steady state substrate concentration The inflow contains the nutrients for the cells present inside the bioreactor and the outflow contains everything present in the broth at a steady-state such as steady-state substrate, biomass, toxins and metabolites. Mass balance for Biomass is given by Rate of inflow of Biomass - Rate of outflow of Biomass + rate of generation of biomass = Accumulation of biomass. In - Out + Rg = Accumulation In= 0 (only nutrients are present in the feed) Out = Flow rate * steady state biomass concentration Rg = Specific growth rate * steady state biomass concentration * Volume Accumulation = 0 (Constant volume) 0 - Fx + uxV = 0 u = F/V = Dilution rate (D) Monods equation u= umax.S/(Ks +S) Here, S = Steady-state substrate concentration Now we know, u = D D = umax.S/(Ks +S) Rearranging the terms in the above equation S = Ks.D/umax-D so now we have a relation between dilution rate and steady-state substrate concentration. #gatebt #gatebiotech #gatebiotechnology