Direction: A microorganism grows in a continuous ‘chemostat' culture of 60 m3 working volume with sucrose as the growth limiting nutrient at dilution rate, D = 0.55 h–1. The steady state biomass concentration is 4.5 Kg dry biomass m–3 and the residual sucrose concentration is 2.0 Kg m–3. The sucrose concentration in the incoming feed medium is 10.0 Kg m–3.
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What would be the yield YX/S (Kg biomass/Kg substrate)?
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- 0.562
- 0.462
- 0.362
- 0.162
Correct Option: A
We know, Yield of biomass, YX/S = Biomass produced/ Substrate consumed
Now, Substrate consumed, S = Initial substrate concentration (Si) – Final substrate concentration (Sf )
= Si – Sf
Si = 10 kg/ m3 and Sf = 2 kg/ m3
Biomass produced, X = 4.5 kg dry biomass/ m3
Therefore, YX/S = X/ (Si – Sf) = 4.5 (10 – 2)
= 0.562 Kg of biomass/ kg of the substrate.
