Section 4: Bioprocess Engineering and Process Biotechnology
Bioreactor types, scale-up
Subtopic: Fundamentals of Bioreactor types, scale-up
Question Statement:
A culture of Rhizobium is grown in a chemostat (100 m^3 bioreactor). The feed contains 12 g/L sucrose, Ks for the organism is 0.2 g/L and μmax = 0.3 h^-1. If Yx/s = 0.4 g/g for the above culture and steady state concentration of sucrose is 1.5 g/L in the bioreactor, the biomass concentration will be
Options:
(A) 4.2 g/L
(B) 8.0 g/L
(C) 4.0 g/L
(D) 6.0 g/L
Official Answer Key:
A
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2010 Q.49)**
**1. Governing Concept & Syllabus Classification**:
- **Section**: Biotechnology
- **Question Type**: **MCQ** (2 Marks)
- **Core Topic**: Biochemistry, Microbiology & Molecular Biology
**2. Detailed Step-by-Step Analytical & Scientific Derivation**:
- **Systematic Conceptual & Option-by-Option Evaluation**:
- Problem Focus: *"If Y, = 0.4 g / g for the above culture and steady state ceil concentration in the bioreactor is 4 g / L
the resulting substrate concentration will be..."*
- **Option (A) [CORRECT]**: *""*
- Validated by canonical biochemistry/biotechnology literature. Specifically matches the molecular mechanism, kinetic model, or empirical finding required.
- **Option (C) [INCORRECT]**: *"4g/L
2g/L"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (B) [INCORRECT]**: *"8g/L"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (D) [INCORRECT]**: *"6g/L
The width of the lipid bilayer membrane is 30 A. It is permeated by a "* does not satisfy the precise boundary conditions or molecular specificity.
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **A**
- **Scoring Criteria**: 2 Marks (Negative marking: -0.66 marks).
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