Chemicals from Glucose via Fermentation

Fermentation is the reproduction of microorganisms in the presence of a source of carbon and energy (such as sugar) and various nutrients. The products of fermentation fall into five major categories  

Macromolecular products excreted by the cells, such as enzymes and polysaccharides 

Primary metabolites, such as acetic acid, acetone, amino acids, citric acid, vitamins, that are essential for cellular growth or result from the conversion of glucose into energy for the living cell 

Secondary metabolites, such as antibiotics, dyes, pigments, aroma compounds, poisons, that are not essential for cellular growth but serve the survival of the species 

Microbial transformations of foreign substrates, often referred to as precursor fermentation. It may be preferred to perform such transformations with whole cells rather than isolated enzymes when the latter approach would involve the recycling of expensive cofactors. Hence, precursor fermentations are often preferred for conducting redox transformations (see Chapter 6). 

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