Question

The formation of inclusion bodies in microbial cell culture is associated with:

• A. Incorrect folding and intracellular accumulation of recombinant proteins.
• B. Incorrect folding and extracellular secretion of recombinant proteins.
• C. Enhanced cell growth.
• D. Lack of nutrients in the medium.

Hint:

To minimize inclusion body formation in bacterial hosts, one can reduce the fermentation temperature, use lower inducer concentrations, or co-express molecular chaperones to aid correct folding.

Answer 1

The Correct Option is A

Step 1: Concept
Inclusion bodies are dense, insoluble aggregates of proteins that frequently form in the cytoplasm (or periplasm) of bacterial cells during the high-level expression of recombinant proteins.

Step 2: Underlying Cause
When recombinant genes are overexpressed at high rates in hosts like E. coli, the cellular folding machinery (chaperones) becomes saturated. This leads to the hydrophobic regions of partially folded polypeptide chains associating with each other, forming misfolded, insoluble aggregates.

Step 3: Elimination
Because these aggregates are kept within the cell (and not secreted outward) and result from structural misfolding, options referring to extracellular secretion or nutritional starvation are incorrect.

Step 4: Conclusion
Hence, the formation of inclusion bodies is directly associated with incorrect folding and intracellular accumulation, matching option (A). Final Answer: (A)