Researchers at the University of Bristol in the UK have taken a major step forward in synthetic biology by designing a system that performs several key functions of a living cell, including generating energy and expressing genes.
Their artificially constructed cell even transformed from a sphere shape to a more natural amoeba shape within the first 48 hours of “life,” indicating that the proto-cytoskeletal filaments were functioning ( or, as the researchers put it, they were “structurally dynamic.” on extended time scales”).
Building something even close to what we might think of as living is no walk in the park, especially since even the simplest organisms rely on countless biochemical operations involving complex machinery to grow and reproduce.
Scientists have previously focused on making artificial cells perform a single function, such as gene expression, enzyme catalysis or ribozyme activity.
If scientists discover the secret to building and programming personalized artificial cells capable of more closely mimicking life, it could create a wealth of possibilities in everything from manufacturing to medicine.
While some engineering efforts focus on redesigning the blueprints themselves, others are investigating ways to reduce existing cells to scraps that can then be rebuilt into something relatively new.
To carry out this latest feat of bottom-up bioengineering, the researchers used two bacterial colonies—Escherichia coli and Pseudomonas aeruginosa—for the parts.
These two bacteria were mixed with empty microdroplets in a viscous liquid. One population was captured inside the droplets and the other was trapped on the surface of the droplets.
The scientists then ruptured the bacteria’s membranes by bathing the colonies in lysozyme (an enzyme) and melittin (a polypeptide that comes from bee venom).
The bacteria spilled their contents, which were captured by the droplets to create membrane-covered protocells.
The scientists then showed that cells were capable of complex processes, such as the production of the energy storage molecule ATP through glycolysis and the transcription and translation of genes.
“Our living materials assembly approach offers an opportunity for the bottom-up construction of symbiotic living/synthetic cell constructs,” says first author, chemist Can Xu.
“For example, using engineered bacteria it should be possible to manufacture complex modules for development in diagnostic and therapeutic areas of synthetic biology, as well as in biomanufacturing and biotechnology in general.”
In the future, this type of synthetic cell technology could be used to improve ethanol production for biofuels and food processing.
Combined with knowledge based on advanced models of basic biology, we could mix and match some structures while completely redesigning others to design entirely new systems.
Artificial cells could be programmed to photosynthesize like purple bacteria, or generate energy from chemicals like sulfate-reducing bacteria.
“We expect the methodology to respond to high levels of programmability,” the researchers say.
This article was published in Nature.