From MIT Technology Review: unlike the conventional genetic engineering currently used in the manufacture of antibiotics and protein drugs such as insulin, synthetic biology involves hacking the entire metabolic system--changing the structure of some proteins, altering the expression of others, and adding in genes from other organisms--to create an efficient microbial machine.
Amyris Biotechnology previous took artemisinin, a potent malaria drug derived from the sweet wormwood tree. By tinkering with yeast's metabolic processes, Keasling and his colleagues were able to boost its production of an artemisinin precursor a million-fold. After just two years of work, they are close to meeting their final goal for the drug--producing it in industrial quantities at prices affordable to developing nations. Now, having created microbial factories that can cheaply churn out carbon-based molecules, the group has turned its attention to biofuels.
Rather than trying to find better ways to make ethanol--the aim of most new biofuel efforts--the researchers chose to create entirely novel biofuels, guided by their own ideas about what a fuel might look like if designed from scratch. (Look in the Merck Index and pick the ideal compound). The researchers selected several candidate compounds based on their energy content (ethanol has only 70 percent the energy of gasoline), their volatility (an ideal fuel shouldn't evaporate too fast), and their solubility in water (unlike ethanol, a water-insoluble fuel could be piped around the country like petroleum. Amyris scientists are now designing metabolic pathways that yield these compounds and tinkering with them to make production as efficient as possible.
This is a powerful pre-molecular nanotechnology approach. Greater protein engineering capabilities can lead to full blown molecular nanotechnology.