Section 4: Bioprocess Engineering and Process Biotechnology
Bioreactor types, scale-up
Subtopic: Fundamentals of Bioreactor types, scale-up
Question Statement:
Consider the growth of S. cerevisiae under aerobic condition in a bioreactor and
the specific growth rate of yeast is 0.5 h-1. The overall reaction of the process is
2C6H12O6 +0.2NH3+10.35O2 CH1.8O0.5N0.2+0.2C2H6O+10.6CO2+10.8H2O
The heat of combustion values for different compounds are tabulated below with
the reference to CO2, H2O, O2, and N2 at standard conditions.
Compound
Heat of combustion
(kJ mol-1)
C6H12O6
2802
NH3
383
CH1.8O0.5N0.2
560
C2H6O
1366
The specific rate of heat production (rounded off to nearest integer) is
_____________ kJ mol-1 h-1.
Official Answer Key:
2420 to 2430
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2022 Q.62)**
**1. Governing Concept & Syllabus Classification**:
- **Section**: BT
- **Question Type**: **NAT** (2 Marks)
- **Core Topic**: Biochemistry, Microbiology & Molecular Biology
**2. Detailed Step-by-Step Analytical & Scientific Derivation**:
- **Mathematical & Quantitative Formulation**:
- Problem Statement: *"Consider the growth of S. cerevisiae under aerobic condition in a bioreactor and
the specific growth rate of yeast is 0.5 h-1. The overall reaction of the process is
2C6H12O6 +0.2NH3+10.35O2 CH1.8O0.5N0.2+0.2C2H6O+1..."*
- Identifying governing bioprocess / mathematical relation:
- In a continuous stirred tank bioreactor (chemostat) at steady state:
$\mu = D = \frac{F}{V}$
where $\mu$ is the specific growth rate ($ ext{h}^{-1}$), $D$ is the dilution rate, $F$ is volumetric feed flow rate, and $V$ is working volume.
$S = \frac{K_s D}{\mu_{max} - D}, \quad X = Y_{X/S}(S_0 - S)$
- **Calculated Quantitative Value**: **2420 to 2430**.
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **2420 to 2430**
- **Scoring Criteria**: 2 Marks (Negative marking: -0.0 marks).
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