8
Chapter 1
are normally referred to as specific rates, and in any physiological study these are the important
rates. That the cells live and interact in a vessel, the bioreactor, is incidental to the cellular reaction,
but we need another term for the rate of reaction based on reactor volume. Here we choose to use
q
as in the first edition of the text. We know that in many other textbooks
q
is used for specific rates.
However, we trust that the reader will accept our choice - even a cursory study of the text will soon
make the nomenclature acceptable, also if the reader happens to be familiar with another
nomenclature.
Also in order to make cross reference to texts in chemical engineering easier we have used a
slightly different nomenclature for concentrations in Chapter 10 and 11 than in the remainder of the
book.
1.3 A Final Note
As educators and academic researchers, we wish to promote an understanding of the subject—
perhaps sometimes to search for the mechanism of a physical or biological process - and in our
effort to contribute to development in general, we wish to assist in the improvement of industrial
processes in the broadest possible meaning of the word
improvement.
On the whole, the present text hopefully illustrates the fundamental engineering cyclic approach to
problem solution:
Ideas breed experiments, which are systematically described by models, which
further lead to new experiments and new model structures - a dictum valid both in
bioprocess design and in systems biology.
REFERENCES
Bailey, J. E. (1991) Toward a science of metabolic engineering.
Science
252:1668-1674
Nielsen, J. (2001) Metabolic engineering.
Appt Microbiol Biotechnol
55:263-283
Nielsen, J., Olsson, L. (2002) An Expanded Role for Microbial Physiology in Metabolic Engineering and Functional Genomics:
Moving towards Systems Biology.
FEMS Yeast Research
, in press
Ostergaard, S., Olsson, L., Nielsen, J. (2000) Metabolic engineering of
Saccharomyces cerevisiae. Microbiol. Mol. Biol Rev.
64:34-50
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