Crude oil is the number one starting material for the synthesis of key chemicals and polymers. As oil becomes increasingly scarce and expensive, biological processing of renewable raw materials in the production of chemicals using live microorganisms or their purified enzymes becomes increasingly interesting. Biological processing, in particular, fermentations have been used for centuries to make beverages. Over the last 50 years, microorganisms have been used commercially to make compounds such as antibiotics, vitamins, and amino acids. However, the use of microorganisms for making industrial chemicals has been much less widespread. It has been realized that microorganisms are able to provide biosynthetic routes to certain compounds. However, such biosynthetic routes can be economically unreasonable depending upon their efficiency.