Low-Cost Microbe: Engineered Bacteria Used As Alternative Host for Scalable Synthetic Biological Experiments

For several decades, Escherichia coli has been used by biologists in protein engineering and other related experiments. In a recent study, a team of researchers claims to have found a better alternative to this microbe.

(Photo: Wikimedia Commons/ UC Davis College of Engineering)

E. Coli as Platform in Protein Engineering

Scientists use a small piece of DNA called a plasmid, which acts as the instructional manual for making a molecular machine or the protein of interest in studying proteins for creating therapeutic drugs or fuels. Conventional methods involve placing a plasmid into E. coli are produced in many copies to test the effectiveness in several variants.

Since the late 1970s, E. coli has been preferable in helping molecular biologists multiply and manipulate plasmids for protein engineering. The bacterial competent cells derived from these microbes are a critical molecular biology component. In fact, their role in protein expression has set the foundation for the modern biotechnology era.

However, using E. coli in biotechnology has some disadvantages. The process is usually expensive since scientists often need to purchase them from manufacturers. Since they need to be kept in a cold environment, they are typically maintained in rooms of expensive equipment. This means that modified E. coli, used in synthetic biology, must be handled very carefully due to their fragility.

Although E. coli is easy to produce, the process is usually tedious and requires tools that can only be found in a typical biological laboratory. This limits the democratization of synthetic biology.

In conducting experiments, scientists do not often know precisely what regulatory or molecular sequences should be achieved to reach their goals. They need to test a lot of variants, so they need a type of microorganism that can help scale up the testing process.

Better Approach in Synthetic Biology

At Cornell University, researchers have created an engineered microbe that demonstrates the ability to synthesize proteins for synthetic biological experiments. Their study is discussed in the paper "Efficient natural plasmid transformation of Vibrio natriegens enables zero-capital molecular biology."

Vibrio natriegens works like an inexpensive multiplier, like a photocopier in a test tube. It helps laboratories test protein variants for developing drugs, synthetic fuels, and sustainable compounds for destroying weeds or pests.

This microbe can be engineered within hours and effectively works without using costly incubators, shakers, or deep freezers. In other words, it is not complicated and is very easy to produce. It is so simple that someone with limited resources can do it.

Led by David A. Specht, the researchers compared the simplicity of Vibrio natriegens in performing synthetic and molecular experiments. They discovered that the process is inexpensive with this engineered bacteria since it does not require capital equipment purchases, and it can also work at room temperature.

Additionally, the cells produced from Vibrio natriegens grow quickly. For instance, a transformation that started at 9 a.m. yields visible colonies by 5 p.m., each filled with masses of proteins. This fast-growing feature is also capable of natural transformation where DNA is drawn from media through an active process under physiological conditions.