Bioreaction Engineering: From Bioprocess Design to Systems Biology

Abstract

Biotechnology is a key factor in the development and implementation of processes for the manufacture of new food products, animal feedstuffs, pharmaceuticals, and a number of speciality products through the application of microbiology, enzyme technology, and engineering disciplines such as reaction engineering and separation technology. With the introduction of the so-called “new” biotechnologies since 1970, directed manipulation of the cell’s genetic machinery through recombinant DNA techniques and cell fusion became possible. This has fundamentally expanded the potential for biological systems to make important biological molecules that cannot be produced by other means. Existing industrial organisms can be systematically altered to produce useful products in cost-efficient and environmentally acceptable ways. Thus, progress in genetic engineering has led to directed genetic changes through recombinant DNA technology, which allows a far more rational approach to strain improvement than by classical methods. This is referred to as metabolic engineering (Bailey, 1991), and in recent years, metabolic engineering has been applied for improvement of many different microbial fermentation processes (Ostergaard et al., 2000; Nielsen, 2001). Initially, metabolic engineering was simply the technological manifestation of molecular biology, but with the rapid development in new analytical techniques, in cloning techniques, and in theoretical tools for analysis of biological data, it has become possible to rapidly introduce directed genetic changes and subsequently analyze the consequences of the introduced changes at the cellular level. Often the analysis will point towards an additional genetic change that may be required to further improve the cellular performance, and metabolic engineering therefore involves a cyclic operation with a close integration between analysis of the cellular function and genetic engineering.