EXPLOITING CELLULAR BIOLOGY TO MANUFACTURE HIGH-VALUE PRODUCTS

he biotechnology industry is expanding rapidly due to advances in understanding complex biological systems and the high demand for biologically manufactured products such as foods and beverages, pharmaceuticals, and commodity and specialty chemicals. The impact of the biotechnology industry on the global economy is substantial. The revenues of the top ten U.S. pharmaceutical manufacturers totaled US$217 billion in 2002 with profits of US$36 billion [1]. A growing biotechnology market is the large scale production of ethanol as a renewable liquid fuel. The production of ethanol in 1998 was 31.2 billion liters worldwide and 6.4 billion liters in the United States with roughly two-thirds of the ethanol produced targeted for biofuel applications [2]. A typical biochemical manufacturing process consists of a reaction step in which a large number of cells are used to synthesize the desired product followed by a series of separation steps, in which the product is recovered from constituents of the reaction liquid. The key requirement for the manufacturing process is the identification of a cell type that converts a relatively inexpensive chemical species to the desired biochemical product. Advances in recombinant DNA technology facilitate the design of