Engineering Microbes for Medicine and Industry
Microbial Cell Factories
Why microbes are ideal platforms
Microbes grow quickly, are easy to manipulate, and can be engineered to produce therapeutic proteins, enzymes, biofuels, amino acids, and specialty chemicals. The central task is redirecting metabolism toward the desired product.
Bacteria vs yeast
Bacteria
- Fast growth
- Simple genetics
- Limited eukaryotic protein processing
Yeast
- Eukaryotic expression machinery
- Useful for some complex proteins
- Usually slower than bacteria
Which product is a common target of microbial engineering?
Microbes are widely engineered to produce therapeutic proteins like enzymes and hormones.
Correct answer: Therapeutic proteins
What is metabolic engineering?
It changes flux through biochemical pathways toward useful products.
Correct answer: Rewiring cellular pathways to increase production of a desired compound
Engineering goals
| Goal | Example |
|---|---|
| Increase yield | More antibiotic precursor production |
| Improve folding | Better secretion of recombinant protein |
| Reduce byproducts | Less waste in fermentation |
| Add new pathway | Synthesis of a non-native molecule |
Why might yeast be preferred over bacteria for some proteins?
Yeast can perform some modifications and folding steps that bacteria often cannot.
Correct answer: Yeast can perform some eukaryotic processing
Industrial reality
A strain that works in the lab may fail at scale, so stability, cost, and growth performance matter as much as pathway design.
Improving a microbial production strain
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1
Step 1: Identify the target molecule and pathway.
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2
Step 2: Add or strengthen biosynthetic genes.
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3
Step 3: Reduce competing pathways.
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4
Step 4: Optimize promoters, copy number, and culture conditions.
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Step 5: Measure yield and iterate.