Millions of years of evolution have created thousands of microorganisms containing enzymes known to catalyze almost every chemical reaction. Nature's exquisite enzymatic chemistry tends toward the highly selective, efficient, temperate, and environmentally benign. Scientists have the ability today not only to identify organisms and their enzymes, but to accelerate normal evolutionary processes and engineer biocatalysts for improved performance.

Challenges exist, however, in coercing nature to work on the industrial scale. With a few exceptions, most applications have been for low-volume, high-value products, such as drugs and fine chemicals.