Metabolic engineering vitamin

Metabolic diseases, liquid crystal accumulations and, 15 112-113 Metabolic engineering, 12 412-413 Metabolic functions, of vitamin A, 25 787-789 Metabolic pathways, as target of antibiotics, 3 24... 

Shintani, D. DellaPenna, D. (1998) Elevating the vitamin E content of plants through metabolic engineering. Science, 282, 2098-100. 

In addition to enhancement with essential vitamins, amino acids, and proteins, plants can also be metabolically engineered to produce nutritionally superior carbohydrates and lipids. The relative inexpensiveness as well as the capability to grow large-scale quantities make plant production an attractive feature. In the case of carbohydrates such as starch and sucrose, many products or modifications of these products can be produced on a large scale and at much lower costs than are currently available. For example, trehalose, a food additive, was in the past too costly for large-scale production however, it has now been produced in transgenic tobacco tissue at a much reduced cost. 

Progress in the techniques of classical strain development and metabolic engineering (Box 24) have made a growing number of fermentation processes feasible and economically attradive. Beside the bulk amino acids, lactic acid, penicillins for the pharmaceutical market, and some vitamins, for example vitamin C (ascorbic acid... 

There are already several examples of chemicals being produced by microbial fermentation of engineered cell factories, whose production through metabolic engineering has been boosted by the use of genomics tools, e.g., 1,3-propanediol used for polymer production, riboflavin used as a vitamin, and 7-aminodeacetoxy-cephalosporanic acid (7-ADCA) used as a precursor for antibiotics production. Furthermore, in the quest to develop a more sustainable society, the chemical industry is currently developing novel processes for many other fuels and chemicals, e.g., butanol, to be used for fuels, organic acids to be used for polymer production, and amino acids to be used as feed. 

As described above, direct production of optically pure LA from a huge variety of mono-, oligo-, or polysaccharides may therefore be possible with a high yield. Thus, cost-efficient LA production is feasible from the view of LA fermentation. However, LAB requires complex nutrients due to their limited ability to synthesize B vitamins and amino acids (Hofvendahl and Hahn-Hagerdal, 2000), and this results in cost-inefficient LA purification. From both a view of metabolic engineering and purification, solutions to this problem should be studied. 

Chemicals. Numerous chemicals, such as amino acids, organic acids, vitamins, flavors, fragrances, and nutraceuticals can be manufactured by metabolic engineering. 

Metabolic Engineering Based on the Two-Step Vitamin C Fermentation Process... 

The classical two-step fermentation process is the most successful route for vitamin C production for its high yield of 2-KLG on D-sorbitol. Though there are two fermentation process, the yield of L-sorbose on D-sorbitol and the yield of 2-KLG on L-sorbose could achieve to more than 99.5 and 97%, respectively. Few of the industrial process could achieve this level. Therefore, the metabolic engineering on the classical two-step fermentation process is always undergoing. 

However, after the report of the innovative two-step fermentation process, the research on the classical two-step based one-step fermentation process seems to be suspended. Few literatures about metabolic engineering of G. oxydans for one-step vitamin C production could be found after then. 

Metabolic engineering of Kluyveromyces lactis for L-ascorbic acid (vitamin C) biosynthesis. Microb. 

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