It is important to note that recombinant DNA technology, one of the enabling technologies for metabolic engineering, did not initiate the biotechnology era. Initially the development of chemical synthesis in microorganisms was highly reliant on experimentation via bioprospecting and random genetic alterations followed by assessment of the resulting physiology (trial-and-error methods). More recently a paradigm shi has occurred toward the more rational and systematic approach of microbial

biosynthesis (Bailey, 1991; Stephanopoulos and Vallino, 1991) whereby taking advantage of the recent developments in molecular biology techniques, analytical methods and improved mathematical models. is approach to altering cellular physiology is commonly known as metabolic engineering. e eld of metabolic engineering has been expanding since the early 1980s though the term was not actually coined until 1991 by Jay Bailey (Bailey, 1991). While this is not a chapter on metabolic engineering, these methods have been and will continue to be highly inuential in the development of recombinant microorganism production platforms for ne chemicals.