GIVING evolution a bit of a kick has provided a way to 鈥渆volve鈥� bacteria quickly and in a controlled manner in the lab. The new procedure has produced cells that make five times as much useful chemical as previous generations did.
Harris Wang and of Harvard Medical School in Boston, and their colleagues, created short strands of DNA that invade Escherichia coli and modify its genes. The strands were customised to simultaneously tweak multiple targets on the bacterium鈥檚 chromosome. By repeatedly introducing a pool of synthetic DNA to the cells, a huge variety of strains can be created quickly 鈥� each one containing genes tweaked in different ways.
They used the process to create billions of unique strains of E. coli in just a few days. All of these strains were then tested for their efficiency in producing 鈥� a chemical closely related to ones that fight cancer and malaria (Nature, ).
Advertisement
At least 20 different genes control lycopene production. This process boosts the chance of hitting upon a combination of mutations that produces vastly more.