Media Sterilization and Stoichiometry

### **Step-by-Step Solution & Mathematical Derivation (GATE BT 2022 Q.29)** **1. Governing Concept & Definition**: - **Topic**: Bioprocess Stoichiometry & Degree of Reductance ($\gamma$) - The degree of reduction of an organic compound $\text{C}_c\text{H}_h\text{O}_o\text{N}_n$ per carbon atom relative to standard reference states ($C = +4, H = +1, O = -2, N = -3$) is: $\gamma = \frac{4c + h - 2o}{c}$ **2. Detailed Step-by-Step Calculation**: - **Given Compound**: Lactic acid ($\text{C}_3\text{H}_6\text{O}_3$): - $c = 3$ - $h = 6$ - $o = 3$ - **Total available electrons**: $\text{Total } e^- = 4(3) + 1(6) - 2(3) = 12 + 6 - 6 = 12$ - **Degree of Reduction per carbon atom**: $\gamma = \frac{12}{3} = 4$ **3. Final Answer**: - **Calculated Value**: **4** - **Official GATE Accepted Range**: **4 to 4**