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Question #46561
The Question
During the conversion of milk to curd, Lactic Acid Bacteria (LAB) produce lactic acid that coagulates and partially digests milk proteins. If a non-toxic chemical buffer is added to fresh milk prior to LAB inoculation, strictly maintaining the pH at 6.8 despite active lactose fermentation, which of the following physiological and ecological outcomes is most likely to occur?
Options
- A.
Casein undergoes complete digestion by LAB proteases, resulting in a clear liquid without coagulation.
- B.
Milk proteins fail to coagulate, and the microbial community shifts towards putrefactive bacteria due to the loss of acidic bacteriostasis.
- C.
LAB hyper-produce lactic acid to overcome the buffer, leading to premature and excessive curdling.
- D.
The LAB inoculum undergoes rapid plasmolysis due to the neutral pH, completely halting lactose fermentation.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Lactobacillus|Lactic_Acid_Bacteria|Decomposition_Rate_Modifiers
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize the NCERT line 'LAB produce acids that coagulate and partially digest the milk proteins' without understanding the underlying biochemical mechanism (pH-induced denaturation of casein at its isoelectric point).
The trap relies on the misconception that LAB enzymes directly and solely cause the physical coagulation of milk, ignoring the critical ecological role of lactic acid in lowering pH to prevent putrefaction (dysbiosis).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Microbes in Human Welfare - Class 12 |
| Concept | Household Product Fermentation Specificity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |