Fermentation vitamin

Certain factors and product precursors are occasionally added to various fermentation media to iacrease product formation rates, the amount of product formed, or the type of product formed. Examples iaclude the addition of cobalt salts ia the vitamin fermentation, and phenylacetic acid and phenoxyacetic acid for the penicillin G (hen ylpenicillin) and penicillin V (phenoxymethylpenicillin) fermentations, respectively. Biotin is often added to the citric acid fermentation to enhance productivity and the addition of P-ionone vastly iacreases beta-carotene fermentation yields. Also, iaducers play an important role ia some enzyme production fermentations, and specific metaboHc inhibitors often block certain enzymatic steps that result in product accumulation. 

Vitamins. Fermentation of citrus molasses by Eremothecuim ashbyii (NRRL 1363) produced nearly 720 p grams/mL riboflavin with 7-9 days of fermentation under optimal conditions (23). Parameters critical to optimal riboflavin production were identified as removal of inhibitory agents from concentrated press liquor by filtration, pH control in a narrow range of 7-8, and adequate levels of reducing sugars. 

P12 Pates, M. M. Effect of orotic acid lysozyme activity of the blood serum. Novoe Biokhim. Fiziol. Vitamin. Ferment, pp. 9-16 (1972) (CA 79 (1973) 51711w) (Russ.)... 

Chem. Descrip. Organic defoamer Uses Defoamer for yeast and vitamin fermentation Properties Liq. sp.gr. 1.002 vise. 400 cps flash pt. (PMCC) > 350 F Mazu DF 289 [Emerald Foam Control]... 

A process that uses the growth of microoi nisms to produce cellular material, such as enzymes and vitamins. Fermentation can also be used to convert complex organic compounds into simpler substances. An example of the latter is the use of yeast to convert sugar into carbon dioxide and alcohol. 

Because of the simplicity of swiae and poultry feeds, most feed manufacturers add vitamins (qv) and trace minerals to ensure an adequate supply of essential nutrients. Amino acids (qv) such as methionine [7005-18-7] lysiae [56-87-17, threonine [36676-50-3] and tryptophan [6912-86-3], produced by chemical synthesis or by fermentation (qv), are used to fortify swiae and poultry diets. The use of these supplements to provide the essential amino acids permits diets with lower total cmde proteia coateat. 

Although a tremendous number of fermentation processes have been researched and developed to various extents, only a couple of hundred ate used commercially. Fermentation industries have continued to expand in terms of the number of new products on the market, the total volume (capacity), and the total sales value of the products. The early 1990s U.S. market for fermentation products was estimated to be in the 9-10 x 10 range. The total world market is probably three times that figure, and antibiotics continue to comprise a primary share of the industry. Other principal product categories are enzymes, several organic acids, baker s yeast, ethanol (qv), vitamins (qv), and steroid hormones (qv). 

Sulfur Dioxide and Sulfites. Sulfur dioxide [7446-09-5], SO2, sodium bisulfite [15181-46-1], NaHSO, and sodium metabisulfite [23134-05-6] ate effective against molds, bacteria, and certain strains of yeast. The wine industry represents the largest user of sulfites, because the compounds do not affect the yeast needed for fermentation. Other appHcations include dehydrated fmits and vegetables, fmit juices, symps and concentrates, and fresh shrimp (79). Sulfites ate destmctive to thiamin, and cannot be used in foods, such as certain baked goods, that ate important sources of this vitamin. 

Dlterpenes. Diterpenes contain 20 carbon atoms. The resin acids and Vitamin A are the most commercially important group of diterpenes. GibbereUic acid [77-06-5] (110), produced commercially by fermentation processes, is used as a growth promoter for plants, especially seedlings. 

Preparation of the vitamins in commercial quantities can involve isolation, chemical synthesis, fermentation, and mixed processes, including chemical and fermentation steps. The choice of process is economic, dictated by the need to obtain materials meeting specifications at the lowest cost. Current process technologies (ca 1997) employed for each vitamin are indicated in Table 9. 

Fermentation. Much time and effort has been spent in undertaking to find fermentation processes for vitamin C (47). One such approach is now practiced on an industrial scale, primarily in China. It is not certain, however, whether these processes will ultimately supplant the optimized Reichstein synthesis. One important problem is the instabiUty of ascorbic acid in water in the presence of oxygen it is thus highly unlikely that direct fermentation to ascorbic acid will be economically viable. The successful approaches to date involve fermentative preparation of an intermediate, which is then converted chemically to ascorbic acid. 

In nature, vitamin A aldehyde is produced by the oxidative cleavage of P-carotene by 15,15 - P-carotene dioxygenase. Alternatively, retinal is produced by oxidative cleavage of P-carotene to P-apo-S -carotenal followed by cleavage at the 15,15 -double bond to vitamin A aldehyde (47). Carotenoid biosynthesis and fermentation have been extensively studied both ia academic as well as ia iadustrial laboratories. On the commercial side, the focus of these iavestigations has been to iacrease fermentation titers by both classical and recombinant means. 

After its separation from Hver extracts, vitamin B 2 was also isolated from cultures of Streptomjces aureofaciens (12). AH vitamin sold commercially is produced by microbial fermentation. 

As noted above, all vitamin is produced by microbial fermentation. A partial Hst of microorganisms that synthesize vitamin B 2 under appropriate conditions follows. Most strains, in their wild state, produce less than 10 mg/L vitamin although a few approach 40 mg/L. The organisms are both aerobes and anaerobes. The carbon requirements in the fermentations are satisfied from sources as wide ranging as hydrocarbons, methanol, and glucose. 

For animal feed use, vitamin B 2 is usuaby provided in a diluted form on a carrier such as calcium carbonate and/or rice hubs. An earher practice of using a spray-dried fermentation biomass in this appHcation appears to be no longer used. 

In contrast to vitamin K, there has been considerably more activity on fermentative approaches to vitamin (50). The biosynthetic pathway to vitamin K2 is analogous to that of vitamin except that poly(prenylpyrophosphates) are the reactive alkylating agent (51,52). Menaquinones of varying chain lengths from to have been isolated from bacteria. The most common forms are vitamin K2 35, (40) (45) significant amount of K2 20)... 

In all fermented foods, microbes contribute as preservatives, ie, by lowering the pH and producing ethanol, or by making the food more palatable. The dehberate use of yeasts as food in themselves is less common. Small beer, the sediment from beer, has been traditionally used as a vitamin supplement for infants. Beginning in 1910, dried, spent brewers yeast was developed as a food, and Candida utilis was used as a food supplement in Germany during World War II. 

The most widely available yeast biomass is a by-product of the brewing industry, where the multiplication of yeast during brewing results in a surplus of ceUs. Eor every barrel (117 L) of beer brewed, 0.2—0.3 kg of yeast soHds may be recovered. In the U.S., a substantial fraction is recovered and made available about 40 x 10 kg of brewers yeast aimually. The yeast is recovered from beer by centrifuging and dried on roUer dmms or spray dryers and sold as animal feed or a pet-food supplement. It can be debittered by alkaline extraction to remove the bitter hop residues, and is then sold mainly by the health-food industry. It is available as tablets, powder, or flakes and is often fortified with additional vitamins. Distillers yeast caimot be readily separated from the fermented mash and the mixture is sold as an animal feed supplement. 

By-Products. After the removal of alcohol, the fermentation residues are processed to produce distiUers grains. These residues consist of proteins, fats, minerals, vitamins, and fiber that are concentrated threefold by removal of the starch. DistiUers grains are usually divided into one of four groups including distiUers dry grains (DDG), distiUers dry solubles (DDS), distiUers dry grains with solubles (DDG/S), and condensed distiUers solubles (CDS). 

Biotransformations are carried out by either whole cells (microbial, plant, or animal) or by isolated enzymes. Both methods have advantages and disadvantages. In general, multistep transformations, such as hydroxylations of steroids, or the synthesis of amino acids, riboflavin, vitamins, and alkaloids that require the presence of several enzymes and cofactors are carried out by whole cells. Simple one- or two-step transformations, on the other hand, are usually carried out by isolated enzymes. Compared to fermentations, enzymatic reactions have a number of advantages including simple instmmentation reduced side reactions, easy control, and product isolation. 

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