Amino acid biotechnology — Corynebacterium glutamicum: This industrial workhorse can be engineered or selected to produce which of the following amino acids?
-
AL-ornithine
-
BL-phenylalanine
-
CL-glutamine
-
Dall of these
Answer
Correct Answer: all of these
Explanation
Introduction / Context:Corynebacterium glutamicum is a premier platform for amino acid production thanks to high flux through central carbon metabolism, robust growth, and genetic tractability. While L-glutamate and L-lysine are classics, many other amino acids are feasible products.
Given Data / Assumptions:
- We consider production possibilities for L-ornithine, L-phenylalanine, and L-glutamine.
- Question allows for native or engineered pathways.
Concept / Approach:C. glutamicum has been engineered to overproduce multiple amino acids: L-ornithine via ornithine cycle deregulation and arginine biosynthesis tweaks; L-phenylalanine via shikimate pathway optimization (aro genes, feedback-resistant DAHP synthase); L-glutamine via coupling glutamate overproduction with glutamine synthetase activity and ammonia assimilation control. Hence, “all of these” reflects current bioprocess capabilities.
Step-by-Step Solution: Map each amino acid to a feasible metabolic route in C. glutamicum. Acknowledge historical and modern strain engineering successes. Select the inclusive option.
Verification / Alternative check:Biotech literature and patents document strain lines for these products using promoter engineering, transporter tuning, and redox balancing.
Why Other Options Are Wrong:
- Single-amino-acid choices understate the organism’s spectrum.
Common Pitfalls:Assuming C. glutamicum is limited to L-glutamate/L-lysine; modern metabolic engineering expands its repertoire.
Final Answer:all of these