Researchers at the University of Bristol in the UK have taken a big step forward in synthetic biology by designing a system that performs several key functions of a living cell, including energy generation and gene expression .
Their artificially constructed cell even transformed from a sphere-like shape to a more natural amoeba-like shape within the first 48 hours of “life”, indicating that the proto-cytoskeleton filaments were functioning (or, as the researchers put it, were “structurally dynamic over extended time scales”).
Building something close to what we might consider alive is no picnic, not least thanks to the fact that even the simplest organisms depend on countless biochemical operations involving incredibly complex machinery to grow and thrive. reproduce.
Scientists have previously focused on obtaining artificial cells to perform a single function, such as gene expression, enzyme catalysis or ribozyme activity.
If scientists unlock the secret to custom building and programming artificial cells that can mimic life more closely, it could open up 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 break down existing cells into pieces that can then be rebuilt into something relatively new.
To achieve this latest feat of bottom-up bioengineering, the researchers used two bacterial colonies – Escherichia coli and Pseudomonas aeruginosa – for 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 burst the bacteria’s membranes by bathing the colonies in lysozyme (an enzyme) and melittin (a polypeptide from bee venom).
The bacteria spilled their contents, which were captured by the droplets to create membrane-covered protocells.
The scientists then demonstrated that the cells were capable of complex processes, such as the production of the energy storage molecule ATP by glycolysis, as well as the transcription and translation of genes.
“Our approach to assembling living materials provides 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 fabricate complex modules for development in the 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, just like sulfate-reducing bacteria do.
“We expect the methodology to meet high levels of programmability,” the researchers say.
This article was published in Nature.