Which statement best describes Escherichia coli in biotechnology?

• A. A yeast used in ethanol production
• B. A bacterium commonly used in recombinant protein production
• C. A mold used in fermentation
• D. A virus used in gene therapy

Answer: (B)

Escherichia coli is a bacterium widely used in biotechnology as a host for producing recombinant proteins. Its rapid growth allows quick, scalable production, and its genetics are exceptionally well understood, with many tools available to insert foreign genes on plasmids and control expression with inducible promoters. This combination makes it a cost-effective, versatile platform for expressing a wide range of proteins, from research enzymes to therapeutic proteins like insulin. Of course, E. coli isn’t capable of some eukaryotic post-translational modifications, so certain proteins may require other hosts for proper folding or glycosylation. This connection to recombinant protein production in a bacterial host is why that statement best describes Escherichia coli in biotechnology, rather than a yeast or mold used for fermentation or a virus used in gene therapy.