What type of organism is primarily used for producing recombinant proteins?

Bacteria are primarily used for producing recombinant proteins due to their rapid growth rates, relatively simple genetic manipulation, and well-understood genetics. The most commonly used species, such as Escherichia coli, can be easily transformed with plasmids containing the desired genes. This allows for efficient production of proteins because bacteria can quickly replicate, carrying the plasmid and producing large amounts of the recombinant protein.

Moreover, bacterial systems are often cost-effective and allow for high yields in a relatively short period. Due to these advantages, many initial studies and commercial applications for recombinant protein production are conducted using bacterial systems.

While other organisms, such as plants, animals, and fungi, can also be used for this purpose, they often involve more complex cultivation and processing steps. Plants might be used for specific proteins that require post-translational modifications present only in eukaryotic cells, while animal cells often provide a more complex environment conducive to producing fully functional proteins but at a higher cost and longer time frame. Fungi can be beneficial for certain applications, particularly yeast, but are generally not as efficient as bacterial systems for straightforward protein production.