The biological evolution of biomolecules is a natural process, but a slow one. Laboratory evolution (or directed evolution) is used to generate biomolecules with tailor-made properties, but it typically proceeds at a rate of one round of evolution every few days and requires frequent sample manipulation.

David Liu and co-workers, Harvard University, USA, have developed a way to produce biological macromolecules 100 times faster than conventional laboratory evolution, and in a less labor-intensive manner. Their approach, “phage-assisted continuous evolution,” or PACE, uses E. coli cells to generate gene-coded molecules linked to protein production. The evolving genes are transferred from host cell to host cell through a modified bacteriophage life cycle. The bacteriophage lifecycle is among the fastest known — just 10 minutes — allowing dozens of rounds of evolution to be performed in a single day.

This work could ultimately allow the tailoring of custom pharmaceuticals and research tools from lab-grown proteins, nucleic acids, and other compounds.

• A system for the continuous directed evolution of biomolecules
  K. M. Esvelt, J. C. Carlson, D. R. Liu,
  Nature 2011.
  DOI: 10.1038/nature09929