Energy Sources

Energy for growth comes from either the oxidation of medium components or from light. Most industrial micro-organisms are chemo-organotrophs, therefore the commonest source of energy will be the carbon source such as carbohydrates, lipids and proteins. Some micro-organisms can also use hydrocarbons or methanol as carbon and energy sources.

CARBON SOURCES Factors influencing the choice of carbon source

It is now recognized that the rate at which the carbon source is metabolized can often influence the formation of biomass or production of primary or secondary metabolites. Fast growth due to high concentrations of rapidly metabolized sugars is often associated with low productivity of secondary metabolites. This has been demonstrated for a number of processes (Table 4.4). At one time the problem was overcome by using the less readily metabolized sugars such as lactose (Johnson, 1952), but many processes now use semi-continuous or continuous feed of glucose or sucrose, discussed in Chapter 2, and later in this chapter (Table 4.15). Alternatively, carbon catabolite regulation might be overcome by genetic modification of the producer organism (Chapter 3).

Table 4.4. Carbon catabolite regulation of metabolite biosynthesis

Metabolite Micro-organism Interfering Reference carbon source

Griseofulvin

Pénicillium griseofuluin

Penicillin

P. chrysogenum

Cephalosporin

Cephalosporium

Was this article helpful?

0 0
Boost Your Metabolism and Burn Fat

Boost Your Metabolism and Burn Fat

Metabolism. There isn’t perhaps a more frequently used word in the weight loss (and weight gain) vocabulary than this. Indeed, it’s not uncommon to overhear people talking about their struggles or triumphs over the holiday bulge or love handles in terms of whether their metabolism is working, or not.

Get My Free Ebook


Post a comment