Last month, researchers from the Universität Marburg reported mixing 12 enzymes from three spheres of life, including plants, humans and microbes, to create an artificial pathway that is more efficient at fixing CO2 than plants. This achievement is just the latest in a host of projects to generate improved metabolic pathways for catalysis or entirely new ones, ranging from artificial production of vanillin to opiates. Such work is made possible by the falling cost of DNA sequencing and synthesis, which means it is possible to ‘read-and-write’ the DNA required to make a variety of enzymes for less than $1000.