Fermentative production microorganisms

There are thousands of breweries worldwide. However, the number of companies using fermentation to produce therapeutic substances and/or fine chemicals number well over 150, and those that grow microorganisms for food and feed number nearly 100. Lists of representative fermentation products produced commercially and the corresponding companies are available (1). Numerous other companies practice fermentation in some small capacity because it is often the only route to synthesize biochemical intermediates, enzymes, and many fine chemicals used in minor quantities. The large volume of L-phenylalanine is mainly used in the manufacture of the artificial dipeptide sweetener known as aspartame [22389-47-0]. Prior to the early 1980s there was httle demand for L-phenyl alanine, most of which was obtained by extraction from human hair and other nonmicrobiological sources. 

Bacteria, yeast and algae are produced in massive quantities of protein sources as food for animals and humans.1 SCP is considered a major source of feed for animals. The production of valuable biological products from industrial and agricultural wastes is considered through the bioconversion of solid wastes to added-value fermented product, which is easily marketable as animal feedstock. The waste streams that otherwise would cause pollution and threaten the environment can be considered raw material for CSP production using suitable strains of microorganisms. 

Many microorganisms represent attractive potential production systems for therapeutic proteins. They can usually be cultured in large quantities, inexpensively and in a short time, by standard methods of fermentation. Production facilities can be constructed in any world region, and the scale of production can be varied as required. 

Microorganisms in liquids and gases can be removed by microfiltration hence, air supplied to aerobic fermenters can be sterilized in this way. Membrane filters are often used for the sterihzation of liquids, such as culture media for fermentation (especially for tissue culture), and also for the removal of microorganisms from various fermentation products, the heating of which should be avoided. 

Savino, A. Lollini, M.N. (1977). Identification of some fermentation products of phenanthrene in microorganisms of the genus Arthrobacter. Bolletino Societa ltaliana Biologa Sperimentale, 53, 916-21. 

Fermentation by microorganisms accounts for a two-thirds share of commercial protease production in the world (Kumar, 1999). Depending on their pH optimum and active-site characteristics, microbial proteases are classified as aspartyl proteases (E.C. 3.4.23, acidic), metalloproteases (E.C. 3.4.24, neutral), cysteine or sulf-hydryl proteases (E.C. 3.4.22, alkaline), or serine proteases (E.C. 3.4.21, also alkaline) (Kalisz 1988 Rao, 1998). Their commercial uses are listed in Table 10.4. 

Pravastatin, a 3-hydroxy-3-methyl glutaryl CoA reductase inhibitor applied as a therapeutic agent for hypercholesterolemia, can be synthesized by stereo- and regioselective hydroxylation of compactin by the soil microorganism Streptomyces sp. Y-110 (Fig. 22) [152]. The fermentative production of pravastatin has already been applied on an industrial scale by Sankyo Co. using different Streptomyces bacteria strains [153, 154]. 

In principle, the same carbohydrates and their degradation products formed after hydrolysis of wood can be recovered from sulfite spent liquors. However, this requires complicated and expensive separation techniques. The industrial use of sulfite spent liquor components is mainly limited to fermentation processes. The most common product is ethyl alcohol which is produced from hexose sugars by yeast (Saccharomyces cerevisae) and separated from the mixture by distillation. Even the carbon dioxide formed in the process can be recovered. Other fermentation products, including acetone, n-butanol, and lactic acid, can be produced by certain microorganisms. Because some contaminants, for example, sulfur dioxide, inhibit the growth of the yeast, they must be removed from the liquor prior to the fermentation. 

Since the discovery of fermentative activity of microorganisms in the eighteenth century and its proof by the French scientist Louis Pasteur, fermentative production of alcohols, amino acids, enzymes (biocatalysts), organic... 

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