ABSTRACT
Fermentation technology is the oldest of all biotechnological processes, dating back thousands of years. It was the means by which bread, wine, beer, and cheese were made. The term “fermentation” is derived from the Latin verb fervere, which means “to boil.” This is because of the frothy appearance of fruit extracts or malted grain acted upon by yeast during the production of alcohol as gas bubbles of CO2 are continuously released. It was only in the 1850s, when Louis Pasteur concluded that yeasts were responsible for fermenting sugar into ethanol and carbon dioxide in anaerobic conditions, that research interest in employing microbes in fermentations in the food and beverage industries and therapeutics was initiated. Biochemists consider fermentation to be an energy-generating process in which organic compounds
7.1 Introduction .................................................................................................. 165 7.2 Submerged Fermentation .............................................................................. 167 7.3 Fermenters .................................................................................................... 168 7.4 Types of Fermenters ..................................................................................... 169
7.4.1 Shake Flasks ..................................................................................... 169 7.4.2 Stirred Tank Fermenter .................................................................... 170 7.4.3 Tower Fermenter ............................................................................... 172 7.4.4 Airlift Fermenter............................................................................... 172 7.4.5 Bubble Column Reactor .................................................................... 174 7.4.6 Fluidized Bed Reactor ...................................................................... 175 7.4.7 Membrane Bioreactor ....................................................................... 176
7.5 Comparison of Mechanically Agitated and Pneumatic Fermenters ............. 177 7.6 Conclusions ................................................................................................... 177 References .............................................................................................................. 178
act both as electron donors and acceptors and an anaerobic process where energy is produced without the participation of oxygen or other inorganic electron acceptors. Industrial microbiologists consider fermentation to be any process (aerobic or anaerobic) for the production of products by means of mass culture of microbes even if the nal electron acceptor is not an organic compound.
