GATE 2022 BT – Question 28
A batch culture has apparent yield 0.5 g biomass/g substrate and initial biomass and glucose concentrations 2 g/L and 200 g/L. With no endogenous metabolism, maximum biomass (g/L) is ___________.
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Correct answer: 102
Explanation
In batch culture with no endogenous metabolism, the biomass formed is proportional to the substrate consumed:
$$X-X_0=Y_{X/S}\,(S_0-S).$$
The **maximum** biomass is reached when all the substrate is used, $S=0$:
$$X_{max}=X_0+Y_{X/S}S_0=2+0.5\times200=2+100=\mathbf{102\ g/L}.$$