Page 65 - Academic Press Encyclopedia of Physical Science and Technology 3rd BioTechnology

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Encyclopedia of Physical Science and Technology EN002G-67 May 25, 2001 20:8

Bioreactors

Yusuf Chisti Murray Moo-Young
University of Almer´ ıa University of Waterloo

I. Introduction
II. Bioreactor Systems
III. Considerations for Bioreactor Design
IV. Concluding Remarks

GLOSSARY the increasing concentration of the product (or sub-
strate) of a reaction slows down the rate of the reac-
Austenitic stainless steels Stainless steels with an spe- tion by interfering with the enzyme(s) that catalyze the
cific type of nonmagnetic crystal structure. reaction.
Downcomer The region of a an airlift bioreactor where Protoplast A cell with its wall removed.
the gas–liquid dispersion flows downwards. Reduced substrate A substrate that contains relatively
Enzymes Protein molecules that catalyze the various bio- little oxygen within its molecules.
chemical reactions. Riser The region of an airlift bioreactor where the gas-
Heterotrophic growth Growth in which the carbon and liquid dispersion flows upwards.
energy for building the biomass are derived exclusively Solidity ratio The ratio of the swept area to the total pro-
from organic chemicals. jected area of the impeller blades, as viewed from di-
Mass transfer Molecular-level transport of any sub- rectly overhead an installed impeller.
stance through any medium. Substrate Any compound that is modified by a cell or
Organelles Well-defined structures associated with spe- an enzyme.
cific functions in a cell. Water-for-injection (WFI) Highly purified water that
Photomixotrophic culture A culture that obtains a part conforms to the WFI specifications of the United States
of the carbon needed for making the biomass from an Pharmacopoeia.
organic chemical and another part from carbon dioxide
via photosynthesis
Phototrophic growth Growth in which the carbon A BIOREACTOR is any device or vessel that is used to
needed to make the biomass comes from fixation of carry out one or more biochemical reactions to convert any
carbon dioxide via photosynthesis. starting material (or raw material or substrate) into some
Pressure drop Loss of pressure with distance down- product. The conversion occurs through the action of a
stream from any point in tubes, channels, and other biocatalyst—enzymes, microorganisms, cells of animals
flow devices. and plants, or subcellular structures such as chloroplasts
Product (or substrate) inhibition A situation in which and mitochondria. The starting substrate may be a simple

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